PS038 – A prospective hazard analysis and pre-implementation
evaluation of non-Luer spinal connectors
Phase 1 - The Potential Hazards Associated With The Implementation of the
Prototype Non-Luer Spinal Connectors (June 2006 – March 2007)
PS038 – A prospective hazard analysis and pre-implementation evaluation of non-Luer spinal connectors 1
Phase 1 - The Potential Hazards Associated With The Implementation of the Prototype Non-Luer Spinal
Connectors (June 2006 – March 2007)
1
1)
Abstract
2
2)
Executive Summary
3
2.1
Task 1: Gaining an appreciation of the problem the new devices are designed to overcome 3
2.2
Task 2: Gaining familiarity with the various devices currently in the prototype stage
2.3
Task 3: Assessing the potential problems associated with the introduction of non-Luer devices 3
3
3)
Introduction
4
4)
Task 1 - Gaining an appreciation of the problem the new devices are designed to overcome
6
4.1
Introduction
4.1.1 Procedures investigated in this research
6
6
4.2
Methodology
7
4.3
Findings and Discussion
8
4.4
Task 1 Summary
9
5)
6)
Task 2 - Gaining familiarity with the various devices currently in the prototype stage
5.1
Summary of SHU, SMTL & BIME evaluations
5.1.1 SMTL Investigation into Non-Luer Compatible Intrathecal Connectors
5.1.2 SHU Product Analysis (October 2006)
5.1.3 BIME Usability Testing
5.1.4 Potential for Misconnection with prototype systems
5.2
Task 2 Summary
10
10
(April 2006) 10
11
12
12
13
Task 3 - Assess the potential problems associated with the introduction of non-Luer devices
13
6.1
Introduction
13
6.2
Methodology
13
6.3
Results and Discussion
6.3.1 Feedback on Prototype Connector Designs
(i)
Prototype 1 System
(ii)
Prototype 2 System
(iii)
Common Disadvantages
6.3.2 Prospective Hazard Analyses
15
15
15
16
17
18
1
6.3.3
6.4
Issues surrounding supply and storage of non-Luer equipment
Task 3 Summary
21
23
7)
Conclusions
23
9)
Glossary
24
10) References
25
11) Appendices
26
1)
11.1 Appendix A: Sheffield Hallam University Product Analysis
26
11.2 Appendix B: Prospective Hazard Analysis Spreadsheets
26
11.3 Appendix C: Hierarchical Task Analyses
26
11.4 Appendix D: NHS Logistics Supply Chain Analysis
26
11.5 Appendix E: SMTL Investigation into Non-Luer Compatible Intrathecal Connectors
26
Abstract
It is widely agreed that an engineered solution to the problem of spinal cross-connection errors is
needed. The DH is currently co-ordinating the design, evaluation and implementation of an
engineered solution in the form of non-Luer compatible equipment for spinal procedures. Within
this wider initiative, this research team has received funding to conduct a prospective hazard
analysis and pre-implementation evaluation of the use of this equipment. The present report
addresses the first of these phases, the prospective hazard analysis, which has recently reached
completion.
The first task of this phase of research was to gain an appreciation of the problem that the new
devices are designed to overcome. A review of the relevant literature revealed that the true
incidence of spinal misconnection errors is difficult to determine due to a paucity of formal incident
reporting. Case reports of documented errors suggest that, as is the case with many adverse
events in healthcare, this type of error often results from the coincidence of a number of
contributory factors.
Further insight into the procedures implicated in this technology implementation was gained
through observation of clinical procedures (including intrathecal chemotherapy and spinal
anaesthesia) and five interviews with consultant haematologists and anaesthetists. Data gathered
during this exercise were used to compile hierarchical task analyses of the relevant procedures,
which formed the basis for the prospective hazard analysis process.
For the second task of this phase, Professor Paul Chamberlain (Sheffield Hallam University) and
his colleagues performed an evaluation of the two proposed design options from an industrial
design perspective. Their report largely verifies the findings of the Surgical Materials Testing and
Bath Institute of Medical Engineering regarding compatibility with the Luer system and usability
issues.
The final and central task of this phase of research was a prospective hazard analysis of the nonLuer spinal equipment. Six prospective hazard analysis workshops were conducted, during which
2
twenty-four healthcare professionals utilised the aforementioned task analyses to systematically
identify potential hazards relating to the use of the novel non-Luer equipment for the relevant spinal
procedures. Workshops investigating intrathecal chemotherapy revealed that: no new hazards
would accompany the introduction of the new devices; there were several shortcomings in the
prototype solutions which need to be addressed; very few procedural changes would be necessary
prior to implementation; and healthcare professionals are supportive of, and enthusiastic, about the
move to non-Luer compatible equipment. It emerged from, workshops examining spinal
anaesthesia, that: anaesthetists feel the focus on spinal injections (rather than on epidural and
intrathecal infusions) is misplaced; the proposed equipment will not provide an engineered solution
to wrong drug errors in this context, due to the way in which spinal anaesthesia is prepared; and
some degree of clinical resistance to the introduction of non-Luer equipment in this area is
anticipated.
2)
Executive Summary
2.1
Task 1: Gaining an appreciation of the problem the new devices are
designed to overcome
Spinal misconnection in oncology and anaesthesia is a significant, well-documented problem. The
introduction of an engineered solution, in the form of non-Luer compatible devices, represents a
further step towards the eradication of spinal maladministration.
Unfortunately, it is difficult to accurately estimate the occurrence of such errors, as it is believed
that many cases have not been formally documented. However, there have been, worldwide, a
minimum of 41 instances of intrathecal injection of vinca alkaloid drugs, 19 cases of
maladministration of other medicines by the intrathecal route, and 29 maladministrations of
medicine by the epidural route, in the last 38 years [5, 6].
Like many adverse events in healthcare, spinal misconnections often result from the interplay of
numerous contributory factors and an approach that considers the ‘system’ in which spinal
misconnections occur will be adopted here. Antecedents found in the literature relate to
prescribing, dispensing, labelling, checking, storage and delivery of drugs; to knowledge,
experience, supervision, training and work schedules of healthcare staff; and to other issues, such
as the location in which procedures are performed, regional differences in protocols, and
dissemination of clinical guidelines.
2.2
Task 2: Gaining familiarity with the various devices currently in the
prototype stage
The two prototype design solutions have been appraised from an industrial design perspective by
Professor Paul Chamberlain and his colleagues at Sheffield Hallam University (see appendix A).
Professor Chamberlain and his team largely verify the findings of the Surgical Materials Testing
(SMTL) regarding compatibility with Luer, and those of Bath Institute of Medical Engineering
(BIME) in terms of the usability of the prototypes. Furthermore, they propose shortcomings in the
sole use of colour coding to differentiate between equipment used for different routes of entry, and
outline potential benefits of the use of shape coding in this context.
2.3
Task 3: Assessing the potential problems associated with the introduction of
3
non-Luer devices
In order to investigate the potential problems associated with the introduction of the new
equipment, six prospective hazard analysis workshops, focusing on the relevant spinal procedures,
were conducted. These involved a total of twenty-four healthcare professionals using a task
analysis of the relevant spinal procedure to systematically investigate the potential for risks in the
use of the novel non-Luer equipment.
During workshops, healthcare professionals were asked to provide feedback on the acceptability of
the two proposed design solutions. The more significant drawbacks of the proposed connection
systems related to: the translucency or opacity of connectors which causes difficulty in observing
cerebrospinal fluid flashback; the small diameter of the holes at the end of prototype syringes
which causes problems in intrathecal chemotherapy preparation; the need to twist the syringe in
order to connect the Prototype 2 syringe to a spinal needle; the relatively heavy weight of the
Prototype 2 connector; and the provision of the Prototype 2 solution in the form of a separable
adaptor.
Workshops focusing on intrathecal chemotherapy revealed that the application of a designed
solution to spinal misconnection errors would not introduce any additional hazards into this area of
patient care, and very few procedural changes would be needed in order to accommodate the use
of non-Luer equipment in this context. Also, the new equipment would decrease the likelihood of
errors in intrathecal chemotherapy drug preparation and labelling. Healthcare professionals are
supportive of the introduction of an engineered solution in the form of non-Luer compatible
equipment.
Workshops addressing spinal anaesthesia found that the proposed prototypes do not present a
design solution in this area of care due to the way in which spinal injections are prepared.
Furthermore, anaesthetists proposed that the focus on spinal anaesthesia is misplaced. They
suggest that errors in anaesthetic spinal/epidural infusions are more common and their
consequences more significant. For these primary reasons, some degree of clinical resistance is
anticipated if either of the current design solutions were implemented.
Several interviews with individuals responsible for the procurement of equipment were conducted.
Regarding supply and procurement of the new equipment, concerns included the initial lack of
competition in the market resulting in prohibitive cost; the proliferation of non-Luer devices if a
more general standard is agreed upon (leading to possible compatibility problems); and the
possibility of delays in implementation due to European trade guidelines. The procurement of the
current and proposed equipment is addressed in a supply chain analysis, conducted by Jonathan
Edwards of NHS Logistics, which is appended to this report (see Appendix D).
3)
Introduction
The Luer connection system is ubiquitous in patient care. Luer connectors are found in a wide
range of devices, including those used for drug administration, feeding and monitoring. On one
hand their universality is desirable – a single piece of equipment may be easily used for a number
of different procedures. On the other hand, however, this interconnectability presents a risk to
patient safety. Luer connectors make it possible for a substance to be unintentionally administered
via a route for which it is not intended. In some cases such ‘misconnections’ have not resulted in
harm to patients. In others they have proved fatal.
4
In 2001, Wayne Jowett died following an injection of Vincristine intrathecally. This drug should only
be administered intravenously. Cases such as this have led Berwick [1] to call for the health
service to follow other high-risk industries in adopting a systems approach to avoiding accidents. In
particular, he has emphasised the need to redesign medical devices to eliminate errors. The
systems approach to risk management focuses not only on the individual, but also on the role of
organisational factors [2]. It is acknowledged that in order to understand the roots of individual
error it is necessary to consider the physical, social and organisational environment in which
individuals operate. From the systems perspective, a crucial distinction is made between active
and latent failures. Active failures are the proximal causes of adverse events. They nearly always
involve individual error or violation and have an immediate negative effect. Latent or organisational
failures, on the other hand, are likely to be removed in time and space from the focal event, but
nevertheless act as contributory factors. For example, the proximal causes of the fatal intrathecal
injection of vincristine at Queens Medical Centre (QMC) were a combination of errors and
violations. However, the external inquiry conducted by Professor Toft highlighted a wide range of
situational and organisational factors that had contributed to the incident, including labelling of
syringes, problems with communication between staff and conflicting protocols [3]. In a summary of
the inquiry Professor Toft concludes “the most dangerous physical aspect of all, in my opinion, is
that the syringe containing Vincristine can also be connected to the spinal needle that delivers
intrathecal drugs to patients. Clearly, once such a connection has been made the patient’s life is in
danger as there are no other safeguards in place to prevent the Vincristine from being
administered”. Thus, in this research programme the immediate risk of spinal misconnection will
be studied within an organisational context. This requires a consideration of the way drugs are
drawn up in pharmacy, delivered to the ward and stored in clinical areas as well as the way the
devices themselves are used.
Others followed in highlighting the need for an engineered solution to the problem of misconnection
errors. In a report to the Chief Medical Officer, entitled 'The Prevention of Intrathecal Medication
Errors' [4] Professor Kent Woods states ‘there should be urgent assessment of the feasibility and
safety of dispensing Vinca drugs either in an infusion bag or in a non-Luer syringe allowing
intravenous administration only’. A further report on Luer connectors, for the European committee
for Standardization (CEN) [5], cites a number of incidents that involved the misconnection of Luer
connectors and suggests that the only way to achieve a safe system would be to design different
male/female connectors that will not allow inter-changeability between intended routes of delivery.
In sum, there seems little doubt about the need for an engineered solution to this problem.
In February 2004, the National Patient Safety Agency (NPSA) published a risk assessment of
spinal procedures for the Department of Health (DH) [6]. This document detailed the risks present
in spinal procedures with the recently introduced DH guidelines in place, and how these risks
would be affected by three potential engineered solutions. The risk assessment concluded that
‘replacing all current spinal equipment with devices with unique spinal connectors would be the
most effective method to minimize the risk of maladministration of vincristine, and would help to
prevent wrong route errors with other medicines and spinal procedures’ (p. 4, par. 18). However,
the NPSA risk assessment also highlights the need to assess the potential hazards associated with
the implementation of this option that may arise from supply, storage and other logistical problems.
5
In a response to a DH advertisement, three medical equipment manufacturers put forward
prototype non-Luer connection systems for use in spinal procedures. Following two rounds of
engineering tests, conducted at the Surgical Materials Testing Laboratory in Bridgend, the DH
Non-Luer Steering Committee (DHNLSC) decided two of these design solutions should progress to
usability testing at Bath Institute of Medical Engineering (BIME). Due to delays in providing
samples, and unsatisfactory performance during testing, the DHNLSC decided that the third
manufacturer should take no further part in the project.
This research group, led by Dr Rebecca Lawton of Leeds University, has been awarded funding to
conduct a prospective hazard analysis and pre-implementation evaluation of non-Luer equipment
for spinal procedures. A series of user tests, conducted using clinician participants in simulated
environments, was originally included in this bid, however, with a need to implement the non-Luer
equipment as quickly as possible, this component was contracted out to Bath Institute of Medical
Engineering (BIME). The present report addresses the first phase of the project, which has
involved three tasks:
1. Gaining an appreciation of the problem the new devices are designed to overcome
2. Gaining familiarity with the various devices currently in the prototype stage
3. Assessing the potential problems associated with the introduction of non-Luer devices
This report will deal with each of these tasks in turn.
4)
Task 1 - Gaining an appreciation of the problem the new devices
are designed to overcome
4.1
Introduction
The first task of phase 1 was to become familiar with the problem of intrathecal (IT) misconnection
errors, in particular the types of errors that have taken place and causal factors that have played a
role in their occurrence. It was also necessary for the research group to gain an understanding of
the spinal procedures for which the non-Luer equipment will be used, the contexts in which the
procedures are performed, and the healthcare professionals that carry them out. In line with the
recommendation contained within the NPSA risk assessment [5], this project is concerned solely
with equipment used for lumbar punctures and the administration of bolus intrathecal doses (these
procedures are described below). Consequently, the research team has not addressed the
following procedures: epidural bolus or continuous administration of medicines; epidural top-up
administration of medicines; combined spinal epidural (CSE) anaesthesia; long term administration
of epidural and intrathecal medicines (including externalised systems, partially externalised
systems and totally implanted systems); neurosurgical ventricular administration of medicines;
neurosurgical implant of medicines; and nerve blocks.
4.1.1
(i)
Procedures investigated in this research
Non-Therapeutic Lumbar Puncture
The purpose of this procedure is to take a sample of the cerebrospinal fluid (CSF) for diagnosis or
monitoring. Following the administration of a local anaesthetic (in adults) or a general anaesthetic
6
(in children), a spinal needle is inserted into the lumbar region of the spine until the needle tip is
located in the subarachnoid space. The sample is then collected by allowing the CSF to drip from
the end of the spinal needle into a pathology sample bottle. When the desired volume of CSF has
been collected, the spinal needle is carefully removed and pressure is applied to the puncture site.
(ii)
Intrathecal Chemotherapy
This involves the administration of bolus doses of chemotherapeutic agents intrathecally as part of
chemotherapy treatment protocols. First, spinal needle placement occurs as detailed in 4.1.1 (i)
(above). A syringe containing the chemotherapeutic drug is then connected to the spinal needle
and the agent is injected into the intrathecal space. The spinal needle is then removed and
pressure is applied to the injection site. It is also common for CSF samples to be taken when
intrathecal chemotherapy is being administered.
(iii)
Spinal Anaesthesia Bolus
Bolus doses of local anaesthetic/analgesic agents are also administered by the intrathecal route to
provide regional anaesthesia/analgesia in an obstetric or surgical context. It is common for a
combination of local anaesthetic and analgesic agents (for instance bupivicaine and diamorphine)
to be administered intrathecally.
4.2
Methodology
In order to understand the types of misconnection errors that have taken place, and to gain an
appreciation of their antecedents, a review of the relevant literature was conducted. This review
included the reports of Professor Brian Toft [3] and Professor Kent Woods [4], in addition to the
NPSA risk assessment of spinal procedures [6]. It also incorporated a literature review conducted
for the Society of Hospital Pharmacists of Australia in 2005 [7]. Further insight into the issues
surrounding spinal misconnection was achieved during interviews with five consultant
haematologists and anaesthetists in the Leeds and Sheffield NHS Trusts.
To gain an appreciation of the procedures implicated in the present technology implementation,
observations of the preparation for, and execution of, spinal procedures were carried out in both
the Leeds Teaching Hospitals NHS Trust, and the Sheffield Teaching Hospitals NHS trust. The
preparation and administration of paediatric IT chemotherapy was observed at both Sheffield
Children’s Hospital and St James' Hospital, Leeds. This was also observed in the context of adult
care at Leeds General Infirmary (LGI). The use of spinal anaesthesia for pain relief during a
cesarean section was witnessed at Royal Hallamshire hospital, Sheffield. Observation of epidural
anaesthesia took place both in a theatre context, at LGI, and in the context of obstetric care, at the
Royal Hallamshire Hospital. The measurement of Cerebrospinal Fluid (CSF) pressure was
observed in the Neurology Day Case Unit at LGI.
During the above observations a 'talk-aloud' protocol [15] was adopted, whereby the clinicians and
technicians being observed were asked to verbalise their actions. This method was utilised to
clarify the sequence of tasks that make up the spinal procedures. The observations and talk-aloud
protocol aided the research team in the production of hierarchical task analyses of the relevant
spinal procedures, which were used as the basis for prospective hazard analysis (PHA). These
task analyses can be seen in the first column of the PHA spreadsheets in Appendix B, and in
Appendix C.
7
4.3
Findings and Discussion
Nature and Incidence of Spinal Misconnection Errors
It is difficult to determine the true incidence of spinal maladministrations, as numerous adverse
events have not been published in the academic literature, and it is thought that many such
incidents have not been documented further than the institutional level [7]. However, from the
incidents reviewed by the Society of Hospital Pharmacists of Australia [7] and the National Patient
Safety Agency Risk Assessment [6], it appears that there have been, worldwide, a minimum of 41
instances of intrathecal injection of Vinca alkaloids, 19 cases of maladministration of other
medicines by the intrathecal route, and 29 maladministrations of medicine by the epidural route in
the last 38 years.
Antecedents of Documented Errors
Adverse events in complex healthcare systems often result from the interaction of numerous
contributing factors. The case of intrathecal maladministration is no exception, as evidenced by the
interplay of events that resulted in the death of Wayne Jowett [3]. A review of the relevant literature
has revealed that the factors listed below can play a causal role in spinal maladministration errors.
It should be noted that the factors listed below are derived from reports of incidents relating to IT
chemotherapy. There is a paucity of information on errors in other spinal procedures (e.g. spinal
anaesthesia).
Prescription – The prescription of IT cytotoxic drugs to be administered at the same time, or on
the same day, as IV Vinca alkaloids creates a situation whereby the two types of drugs may
become confused with one another, or a clinician may assume both drugs are for IT delivery (e.g.
[8]). Also, the use of a single chemotherapy prescription chart for all chemotherapy, regardless of
administration route, may make administration errors more likely.
Dispensing – The dispensing of chemotherapy by those untrained in cytotoxic drugs contributed
to error in at least one case.
Storage – The holding of IV and IT medications in a common cupboard/fridge in pharmacy or on
the ward may lead to the incorrect drug being selected for administration (e.g. [9]). Further, the
storage of chemotherapy in unlocked fridges makes their administration less regulated and more
prone to error.
Delivery – The arrival of IT and IV medicines to the treatment room at the same time increases the
likelihood of drug confusion (e.g. [10]).
Location – The administration of IT chemotherapy outside of a specialist cancer ward or unit may
contribute to error (e.g. [11]).
Regional Differences – Variation in procedures between different trusts may play a causal role in
spinal maladministration. For instance, in the Wayne Jowett case [3] one clinician expected IT
medications to be delivered in a distinctly coloured container, as was standard practice in his
previous trust. However, this was not the policy of his new employer.
Labelling – Several labelling issues are evident in the literature. Syringes containing
chemotherapy have been prepared but not labelled, with labelling only being applied to outer
packaging. ‘Mislabelling’ of syringes has also been stated as an antecedent (e.g. [12]). Some
8
labels have been found to be inadequate as the drug name, route of administration, or treatment
warnings were written in too small a font, were incomplete or were not sufficiently highlighted (e.g.
[9]). Also the similarity between the packaging of IT and IV drugs has lead to confusion [3].
Knowledge – Lack of understanding or inexperience in chemotherapy administration and its’
related procedures has been cited as a causal factor in spinal errors (e.g. [12]). This is more
probable when clinicians are providing cover outside of their specialty (e.g. [11]), and so are more
likely to be unfamiliar with the medicines being administered.
Supervision – In some reported cases, new or junior staff were not adequately supervised by their
superiors, leaving them free to perform procedures for which they lacked the necessary experience
(e.g. [13]).
Training – Lack of formal orientation or training in IT chemotherapy procedures in a clinicians’ new
place of work may contribute to spinal administration errors. The absence of formal evaluation to
ensure that new members of staff had read and understood ward guidelines played a part in one
case [3].
Fatigue – Overworking can lead to a reduction in vigilance that makes errors more likely to occur.
In one instance a doctor had been on duty for 30hours when he accidentally picked up a syringe of
Vincristine instead of Methotrexate [13].
Changeover – The changeover of staff has occurred during the preparation of the patient, or in
between checking and administration of treatment. This scenario may increase the likelihood of
error (e.g. [9]).
Checking – Failure to perform a second check prior to administration was reported as contributing
to one error in the literature [14]. On other occasions, inadequate checking has been reported,
where labels were not read carefully, or were not checked against the prescription sheet. Failure to
include patients in the checking procedure is also an issue of concern.
Guideline Dissemination – Despite drug administration guidelines being in place in one site, their
inadequate dissemination meant that some members of staff were unaware of them, creating
capacity for error [3].
Equipment – Ultimately, the fact that syringes containing medications meant for IV administration
were compatible with needles used for IT administrations allowed drugs to be given via the wrong
route.
4.4
Task 1 Summary
•
Procedures investigated include non-therapeutic
chemotherapy and spinal anaesthesia
lumbar
puncture,
intrathecal
•
At least 41 instances of intrathecal injection of Vinca alkaloids and 19 other intrathecal
maladministrations have occurred worldwide
•
Intrathecal misconnection commonly results from a combination of contributory factors
9
5)
Task 2 - Gaining familiarity with the various devices currently in
the prototype stage
As part of the first phase of research, the two prototype connection systems were appraised from
an industrial design perspective by Professor Paul Chamberlain and his associates at Sheffield
Hallam University (SHU). Please see Appendix A for their full report. Their findings largely validate
the findings of a previous battery of tests conducted at the Surgical Materials Testing Laboratory
(SMTL), Bridgend, conducted between March 2004 and March 2006. Please see Appendix E for
this report. As part of the wider project, usability testing of the prototype equipment in a simulated
environment was conducted by Craig Davey and his colleagues at Bath Institute of Medical
Engineering (BIME). Findings of the BIME usability evaluations are summarised in 5.1.3, below.
5.1
Summary of SHU, SMTL & BIME evaluations
5.1.1
SMTL Investigation into Non-Luer Compatible Intrathecal Connectors
(April 2006)
Three manufacturers provided prototype non-Luer connectors for engineering and usability testing
at SMTL: Manufacturer 1, Manufacturer 2 and Manufacturer 3. A number of problems in material
selection and design were identified during the first round of testing. Manufacturers were given the
opportunity to rectify these issues before providing equipment for a second round of tests.
Following the second round of SMTL evaluations, the DHNLSC decided that the manufacturer
Manufacturer 3 should have no further involvement in the project. Their delay in providing
prototypes impeded the SMTL evaluations, and the equipment provided for testing was not of a
satisfactory standard to progress to the next stage of the project. Consequently, they will be
omitted from this summary of the SMTL report on the second round of testing.
(i)
Bench Tests
Testing was based on the European standard for Luer Lock fittings (BS EN 1707: 1997). First,
prototypes were subjected to a battery of bench tests investigating their material integrity. These
included evaluations of liquid leakage, air leakage, separation force, unscrewing torque, and
resistance to overriding. Performance of the Prototype 1 and Prototype 2 connectors are
summarised in the table below. It can be seen (in table 1 below) that Prototype 1 (pictured in Fig 1,
page 14) passed 10/10 tests in each of the 5 areas. The mean pass score of the Prototype 2
equipment (pictured in Fig 2, page 15) was 8.2/10.
Table 1: Performance of Prototype 1 and Prototype 2 on SMTL Bench Tests
Test Performed
Prototype 1
Prototype 2
Liquid leakage (No. Passed)
10/10
6/10
Air leakage (No. Passed)
10/10
6/10
Separation Force (No. Passed)
10/10
9/10
Unscrewing Torque (No. Passed)
10/10
10/10
Overriding Force (No. Passed)
10/10
10/10
10
(ii)
Ease of assembly and non-interconnectability with Luer
Next, the SMTL team asked 11 healthcare professionals (5 consultant anaesthetists, 1 senior
health officer, 3 clinical nurse specialists, 1 pharmacist and 1 head of nursing in accident and
emergency) to provide feedback on the ease of assembly of the two prototype systems.
Participants commented that: connectors fitted well together, but that they were difficult to
disengage; connectors were small and fiddly; the material felt hard and brittle. Concerning the
Prototype 2 equipment, healthcare professionals felt that: the connectors were easy to grip and
had a ‘nice feel’; the distinct colour aided with differentiation from other equipment; the soft material
would make it easier to cross connect.
In addition to providing feedback on usability, healthcare personnel were also asked to attempt to
connect the two non-Luer prototypes with 20 different traditional Luer devices used in the NHS.
The resulting misconnections were classified as ‘full’, ‘partial’, or ‘none’. A number of full and partial
connections were achieved with both manufacturers’ systems. The Prototype 1 equipment was
found to be superior in terms of its non-compatibility with the Luer devices, with 93.3% of total
cross-connection attempts classified as ‘none’. The comparative figure for Prototype 2 cross
connections was 73.3%.
Following the cross connection exercises, the SMTL technical group attempted to recreate the
misconnections achieved by healthcare professionals in order to investigate whether these full or
partial connections would permit delivery of a 1ml bolus of water. The team attempted to deliver
the bolus at both high and low speed and in both the vertical and horizontal planes. Various
scenarios were encountered, ranging from successful delivery of the whole bolus though to no
passage of fluid whatsoever.
5.1.2
SHU Product Analysis (October 2006)
In addition to usability issues, the SHU team were keen to further investigate compatibility of the
prototypes with Luer connectors, following SMTL reports that some of the cross connections
achieved by healthcare professionals could not be recreated by the SMTL technical team.
(i)
Misconnectability
The SHU team concludes that both Prototype 1 and Prototype 2 non-Luer compatible connection
systems could prevent a syringe with a standard male Luer connector being wrongly attached to a
spinal needle. This is because in both prototypes the aperture of the female non-Luer fitting is
smaller than the narrow end of a standard male Luer tapered connector, so male and female will
not mate. As an exception to this, it proved possible to force the male Luer connector of a standard
syringe into the female connector of a Prototype 1 epidural needle. However, in this case the
forces required to misconnect exceeded those of normal use.
(ii)
Usability
Regarding Prototype 1, the Sheffield Hallam team concurred with feedback obtained during SMTL
usability evaluations. They too found the Prototype 1 devices small and fiddly, with a harsh grip
area making the connectors uncomfortable to use. However, regarding the small size of the
Prototype 1 connectors, they suggest that patient comfort should be taken into account. Larger
connectors could be heavy when attached to the patient, leading to discomfort. The Prototype 2
11
male connector is significantly larger than Prototype 1, providing a good-sized grip area. However,
the female fitting on the Prototype 2 spinal needle lacks adequate grip provision - a sharp flange
making the device uncomfortable to handle.
(iii)
Equipment Identification
The SHU report also contains a discussion on the differentiation of equipment used for delivery of
drugs by different routes. The authors express misgivings about the use of colour coding in this
differentiation, and propose that haptic (shape) coding may be prove valuable in this context.
5.1.3
BIME Usability Testing
The usability of the Prototype 1 and Prototype 2 equipment was examined by Craig Davey and his
colleagues at BIME. Three clinically relevant scenarios (spinal anaesthesia, epidural analgesia and
intrathecal chemotherapy) were simulated to assess the usability of the two different prototype
systems. Thirty clinicians, with a range of skills and experience, were recruited to participate. Each
clinician performed a simulated procedure, first using standard equipment and then each prototype
system (in random order). An anatomically realistic spinal trainer dummy and appropriate ancillary
equipment (including sterile gloves and drapes) were used to add realism to the scenarios. Each
participant was filmed throughout, and gave feedback by semi-structured interview. Data analysis
was based on observations and interview responses.
After the first round of testing, both manufacturers were offered the opportunity to modify their
prototypes in the light of recommendations and to resubmit equipment for further tests. Only one
manufacturer (Prototype 1) submitted modified equipment. This was retested using the same three
scenarios.
The first round of testing generated a number of recommendations for each manufacturer to
address. Manufacturer 2 were informed that reliance on a detachable adaptor was not considered
a sufficient safeguard against possible misuse/bypass in a complex clinical environment. They did
not submit modified prototypes to address this key issue.
For the Prototype 1 system, the second round of testing generated more favourable feedback.
Higher satisfaction ratings were given and no clinicians regarded the system as unacceptable in its
current form. Prototype 1 was, therefore, considered to be sufficiently well developed to go forward
into the next round of the wider Department of Health project – a clinical implementation study.
5.1.4
Potential for Misconnection with prototype systems
The potential for cross-connection of non-Luer syringes and Luer needles was raised in the SHU
and SMTL reports. This issue has been investigated in collaboration with our clinical contacts.
First, it should be said that when we invited clinicians (a consultant anaesthetist and a consultant
haematologist) to attempt this misconnection (by trying to join Prototype 1 non-Luer syringes to
Luer spinal needles), they commented that the force needed to achieve a (partial) connection was
“way beyond” that which would be applied in clinical practice. As consultant paediatric
haematologist Sally Kinsey put it, the force required is “not clinically relevant”. Spinal needles will
be placed intrathecally. Therefore, the application of anything other than very slight force during
connection endangers the patient. Also, as consultant anaesthetist Martin Dresner pointed out, in
the extremely unlikely event that the non-Luer syringe were held next to a Luer spinal needle
12
horizontally, in an attempt to ‘squirt’ the drug into the needle, the drug would not advance down the
needle due to pressure from the CSF leaving the spine.
However, to further mitigate this risk we would recommend the complete removal of Luer spinal
needles from the clinical area. The practicalities of removing Luer equipment from clinical areas will
be investigated further in the implementation study planned within the Leeds trust.
It is the opinion of the research team that, due to the considerable force required, and the removal
of Luer equipment from clinical areas, the potential for misconnection identified by our
collaborators at Sheffield Hallam is as low as is reasonably practical.
5.2
Task 2 Summary
•
Prototype 1 performed better than Prototype 2 during SMTL bench tests and noninterconnectability with Luer exercise
•
Prototype 1 usability issues: fiddly, uncomfortable to use, difficult to disengage
•
Prototype 2 usability issues: soft material allows greater capacity for cross-connection,
larger size and heavier weight may cause discomfort, spinal needle lacks adequate grip
provision
•
Clinicians suggest potential for misconnection reported by SHU and SMTL ‘not clinically
relevant’
6)
Task 3 - Assess the potential problems associated with the
introduction of non-Luer devices
6.1
Introduction
When implementing new technology with the intention of enhancing a specific aspect of patient
safety, it is important to ensure that the proposed equipment will lead to the desired safety
improvements. However, it is equally important to ensure that these benefits are not achieved at
the expense of safety in associated areas. The introduction of non-Luer equipment for spinal
procedures, in addition to preventing the cross connection of equipment during IT procedures,
should not introduce any new hazards into patient care.
6.2
Methodology
From the information obtained during the literature review, and through observations of clinical
practice, hierarchical task analyses were produced for each of the relevant spinal procedures.
These include: non-therapeutic lumbar puncture; the measurement of CSF pressure using a spinal
manometer; IT chemotherapy; and spinal anaesthesia. The task analyses of IT chemotherapy and
spinal anaesthesia formed a basis from which the systematic investigation of potential hazards
inherent in these procedures could take place. This prospective hazard analysis (PHA) process
took place during six workshops, which were conducted in collaboration with Geoff Simpson (of
Asher Risk Consulting). Please see table 2 (below) for a summary of the workshop attendees,
areas of focus and locations.
A total of twenty-four healthcare professionals attended the six PHA workshops. Amongst these
were eleven consultants, five pharmacists, four nurses, two specialist registrars and two
13
technicians. Workshops lasted approximately three hours and involved three stages: first, the task
analyses compiled by the research fellow were reviewed by the attendees, and modified where
they did not accurately capture the nature of the spinal procedure in question. Next, the verified
task analyses were used to review the spinal procedures systematically in an effort to identify
potential hazards in their preparation or performance. For each step in the task analysis,
participants were asked to consider how the introduction of the non-Luer equipment could
potentially introduce risk into the procedure. The focus of this exercise was on the way in which the
introduction of non-Luer equipment would impact upon the performance of spinal procedures:
whether changes in work practices will be required, and where difficulties in the implementation
process might arise. Therefore, the hazard analysis provides an insight into the potential for new
risk rather than a description of existing risks associated with spinal procedures. The hazard
analysis method used was a combination of HAZID (originally developed by the Institute of
Chemical Engineers) and Potential Human Error Assessment (PHEA - originally developed by
British Coal). HAZID (Hazard Identification) is one of the subsets of the technique commonly
defined under the general title of Hazard & Operability Studies (HAZOPS) [16]. The combination of
techniques is important as HAZID ensures a systematic and comprehensive approach to hazard
identification and PHEA focuses on the errors that represent precursors to hazards. This hybrid
PHA approach has been used extensively during the investigation of human error in the coal
mining and nuclear power industries, by our collaborator at Asher Risk Consulting. However, as it
is yet to be thoroughly evaluated in a healthcare setting, it should be noted that it remains an
experimental technique.
During workshops, there was some degree of time pressure to complete the PHA process.
Therefore, it was not possible to classify the potential errors that were elicited through the
procedure into different categories. This categorisation was done by the research fellow and the
risk consultant following the workshops. Firstly, errors were classified in terms of whether they
were errors in the input, decision or output stage of a task. Errors were also classified according to
whether they could be characterised as slips, lapses, mistakes or violations [17]. Slips and lapses
occur when an action sequence appropriate to the situation is executed incorrectly. Slips are
observable, whereas lapses are not. A mistake is the successful execution of a faulty plan of
action, and a Violation is a deliberate breach of rules or procedures.
Finally, after this process of hazard analysis, attendees were provided with examples of prototype
equipment from each of the two manufacturers (in the form of syringes and spinal needles). They
were asked to provide feedback on the acceptability of the respective prototypes from the point of
view of their involvement in the spinal procedures.
Table 2: PHA Workshop Attendees and Areas of Focus
Date & Time
Focus
Location
Attendees
24/01/07
IT Chemotherapy
Sheffield Children’s
1 consultant,
10am-1pm
(Paediatric)
Hospital
1 specialist registrar,
2 pharmacists,
1 nurse
08/02/07
IT Chemotherapy
2.30-5.30pm
(Adult)
Leeds General Infirmary
1 consultant,
1 pharmacist,
14
1 pharmacy technician,
1 nurse
12/02/07
Spinal Anaesthesia
10.30am-
(General/Theatre)
Leeds General Infirmary
1 consultant,
1 specialist registrar,
1.30pm
1 risk management pharmacist
20/02/07
Non-therapeutic
2pm-5pm
Lumbar Puncture in
Leeds General Infirmary
2 consultants
Neurology and A&E
28/2/07
IT Chemotherapy
St James’ Hospital
2 consultants,
1.30-4.30pm
(Paediatric)
(Leeds)
1 pharmacist,
1 pharmacy technician,
2 nurses
01/03/07
Spinal Anaesthesia
Royal Hallamshire
9am – 12pm
(Obstetrics)
Hospital (Sheffield)
6.3
4 consultants
Results and Discussion
The spreadsheets produced during the hazard analysis workshops can be seen in appendix B. For
reasons that are given below, the full hazard analysis process was not executed in the workshops
concerning spinal procedures in anaesthesia, nor in the workshop examining non-therapeutic
lumbar punctures in neurology and A&E.
Feedback on the specific connector designs, in addition to several problems that they share, is
presented below. This is followed by a summary of issues related to the introduction of non-Luer
equipment in the context of spinal procedures in oncology/haematology, anaesthetics, neurology,
and A&E. Finally, issues surrounding the procurement and storage of the novel non-Luer
equipment are discussed.
6.3.1
(i)
Feedback on Prototype Connector Designs
Prototype 1 System
Most of the workshop attendees commented that the Prototype 1 equipment (Fig 1, below) was
easier to connect than Prototype 2. They also noted that it was more similar to the current Luer
equipment used for spinal procedures. They asserted that the hub of the connector was
comfortable, and that the ridges on the needle provided grip, without being too sharp. The fact that
the syringe connector could slip into to the spinal needle without the need to rotate it was seen as
beneficial, as clinicians suggested that any movement needed to make the connection could cause
undesirable movement of the needle tip (within the patient). Also, the option to make a locked
connection, afforded by the rotating collar, was seen as desirable, though clinicians were unsure
how often this feature would be used in the context of spinal injections (it was thought that this
would be used primarily during infusions in anaesthesia). On the negative side, some of the
attendees thought that the material appeared to be of a lower quality, and seemed more fragile
than that used in the Prototype 2 connector. It was also proposed that the rotating collar could
present an infection risk.
15
Figure 1. The Prototype 1 Non-Luer Equipment
(ii)
Prototype 2 System
The positive aspects of Prototype 2 (Fig 2, below) seemed to be derived mainly from its’ aesthetic
qualities. Clinicians thought that it appeared to be neater, simpler and more robust than Prototype
1, and that the material used was more comfortable to handle. It was also noted that this prototype
provided a secure, positive connection, even though most clinicians agreed it was more difficult to
achieve the connection than with the Prototype 1 connector. Several disadvantages of Prototype 2
emerged. Firstly, that it is necessary to twist the syringe to attach it to the spinal needle was seen
as problematic, as this twisting could cause the tip of the spinal needle (within the patient) to move.
Clinicians also remarked that, relative to the Prototype 1 connector, the Prototype 2 design is very
heavy. This was of particular concern in paediatric care, where the weight of the connector,
attached to a spinal needle in a young child or neonate, could be a further source of undesirable
needle tip movement. The disadvantages mentioned above, however, were eclipsed by one major
criticism, on which all attendees agreed: The provision of the connector as an adaptor, which can
be separated from the end of the syringe, does NOT represent an engineered solution to the
problem of spinal misconnection.
16
Figure 2. The Prototype 2 Non-Luer Equipment
(iii)
Common Disadvantages
Several criticisms were lodged against both prototype designs. First, the small diameter of the hole
at the end of the syringe connector was viewed as problematic from the perspective of IT
chemotherapy preparation in aseptics at LGI. This is because the IT cytotoxic drugs are pushed
through a microbiological filter and ‘squirted’ into the syringe from which they will be administered.
This practice is dependant on the diameter of the hole at the end of the syringe being sufficiently
large to allow a needle to be inserted into it easily. Pharmacy technicians (whose responsibility it is
to prepare the IT administrations) thought that the diameter of the hole at the end of both prototype
connectors was small enough to make this practice difficult. It should be noted here that it is
possible to fill the administration syringe without using this process. IT chemotherapy preparation
at St James’ Hospital, for instance, utilises a syringe-to-syringe connector for this purpose, which
foregoes the need to squirt the drug into the administration syringe. This piece of equipment joins
to the microbiological filter, allowing the IT drug to pass through into the administration syringe.
This method is thought (by St James’ staff) to be superior to the ‘squirting’ method used at LGI, as
it reduces infection risk by maintaining a closed system. The research team therefore proposes
that non-Luer syringe-to-syringe connectors are provided for use during preparation of IT
chemotherapy.
The second common problem is of greater concern with regards the Prototype 2 connector. When
IT drugs are prepared and administered, it is important that good visibility of the end of the
syringe/needle is maintained. This allows technicians and clinicians to see when the syringe is fully
primed and to observe flashback of CSF (necessary to ensure that the needle is located
intrathecally, and to determine if any blood vessels have been disturbed during needle placement).
As the connectors are translucent (Prototype 1, see fig 1, page 14) and opaque (Prototype 2, see
fig 2, page 15), the view of the end of the syringe is either partially or totally obscured, respectively.
This was seen as a major problem in the context of both chemotherapy and anaesthesia. It was
proposed that, instead of applying colour to the connectors themselves in order to provide visual
discrimination between IT equipment and other devices, it would be more appropriate to make the
syringe plunger a distinct colour. This would provide visual differentiation of IT devices, without
obscuring the view of CSF flashback. This approach has been adopted successfully in other parts
of the world. For instance, red plungers have been used in Australia to denote syringes containing
muscle relaxant drugs since 1994 [17].
The fact that the prototype connectors add a small amount of volume at the end of the syringe was
of concern for some of the clinicians. In both IT chemotherapy and spinal anaesthesia, the volumes
of drugs being injected can be very small, so it is imperative that the full dose is administered.
Clinicians were unsure as to whether or not this increased ‘dead space’ would have a bearing on
the volume of drug entering the spine (or remaining in the syringe). They suggested that the dead
space should be taken into account when applying graduation markings to syringes.
Attendees at one of the oncology workshops commented that the syringe plungers on the
prototypes provided were very stiff. It was thought that the syringes used in the production of
prototypes were themselves stiff, and that this was perhaps exacerbated by the small diameter of
the hole at the end of the non-Luer connectors. A senior technician at St James’s hospital
explained that they have experienced problems with repetitive strain injury in the staff that prepare
17
drugs in aseptics. It was proposed that, if the syringe plunger on the final product remained as stiff
as in the prototype devices, this could increase occurrence of repetitive strain injury, impacting
negatively on staff acceptance of the new equipment.
Finally, the syringe graduations applied to the prototype syringes were thought to be too large. As
mentioned above, small doses of IT drug are often prepared, and finer graduations on the syringe
are needed to facilitate this. Markings every 0.1ml and 0.2ml are required, rather than every 0.5ml,
as was the case with the prototypes provided.
6.3.2
(i)
Prospective Hazard Analyses
IT Chemotherapy
A summary of the issues emerging from the PHA of IT chemotherapy in adult and paediatric care
is presented below. For the complete spreadsheets generated form PHA workshops in adult and
paediatric care, see Appendix B (i) and B (ii) respectively.
National guidelines for the safe administration of intrathecal chemotherapy were issued by the DH
in November 2001 [HSC 2001/22], and were later updated in October 2003 [HSC 3003/010].
These guidelines specify that IT chemotherapy may only be prescribed, made up, checked,
handled and administered by designated healthcare professionals that have demonstrated an
understanding of the capacity for maladministration of IV and IT drugs in this context. In addition to
only being carried out by clinicians that are on this IT register, IT chemotherapy may only be stored
and administered in specified areas, at specified times. Explicit within these guidelines is that bolus
intravenous, intramuscular or subcutaneous chemotherapy drugs must not be prepared, stored, or
administered in the areas designated for IT chemotherapy preparation, storage or administration.
Following the introduction of these guidelines, the protocols for preparation and administration of IT
chemotherapy are robust. The PHA analysis revealed that repeated routine checking within the
process allows for slips, lapses or mistakes in prescription or preparation to be recovered.
However, while the non-Luer devices provide a final line of defence should these checking
processes fail, it should be noted that the possibility remains for the wrong drug to be drawn up into
the non-Luer syringe, although the visual discrimination afforded by the new non-Luer devices will
further reduce this risk.
Given that IT chemotherapy is now strictly controlled, and the safety of the process has therefore
been enhanced, it was a concern of the research group that healthcare professionals would see
limited benefit in the application of non-Luer compatible equipment. However, this does not appear
to be the case. All staff attending the oncology/haematology workshops were enthusiastic about
the introduction of a design solution to this problem. It seems, from their point of view, that any step
which makes the preparation or administration of IV drugs distinct from that of IT drugs is a
worthwhile endeavour. The PHA analysis suggests that the increased visual differentiation of IV
and IT syringes provided by the new equipment will decrease the likelihood of mistakes in drug
preparation and labelling.
The PHA analysis revealed a problem with the current practise of using Luer slip caps to ‘cap-off’
IT chemotherapy doses. Presently, the use of slip syringe caps means that, if a small amount of
pressure is applied to the plunger of the syringe, the cap can shoot off. This means that the dose
must be made up again, costing the trust time and money. The non-Luer locking syringe caps will
18
be superior to the Luer slip caps that are currently used, as they will prevent this situation from
occurring.
One potential barrier to the introduction of non-Luer spinal equipment in this context is the
increased cost of the new devices. Because of this, workshop attendees enquired as to whether
the current Luer equipment could be used during the preparation of IT chemotherapy, and during
the performing of non-therapeutic lumbar punctures, in an effort to reduce the cost to trusts. In
these situations, where either no patient is present, or no drug is being administered, it was
thought that there was no benefit of using (more expensive) non-Luer safety equipment. Whereas
it is important to consider factors that will enhance acceptance of the new non-Luer equipment, the
research team believes that the continuation of use of Luer equipment for any tasks allied to the
preparation or administration of intrathecal agents is undesirable. The research team recommends
that in order to achieve an engineered solution to the problem of spinal misconnection it is
necessary to adopt a consistent approach, which entails the replacement of all Luer spinal
equipment with a non-Luer counterpart.
The PHA process revealed that very few procedural changes would need to be made in order to
accommodate the use of non-Luer equipment for IT chemotherapy. This was expected, due to that
fact that the only significant difference between the non-Luer devices and their predecessors is in
terms of their physical incompatibility with Luer. The only minor change needed seems to be the
modification of drug preparation worksheets, which are used during the making up of IT cytotoxics.
These sheets specify the pieces of equipment that will be used whilst preparing the IT drug for
administration, and will need to be altered to reflect the change to non-Luer equipment.
Overall, the PHA process revealed that no new hazards would be introduced into the process of IT
chemotherapy preparation and administration by the implementation of non-Luer equipment. In
addition to physically preventing the connection of an IV drug-containing syringe to a spinal needle
(in the extremely unlikely event that the two existed together in the clinical arena), the introduction
of non-Luer devices will have further benefits for healthcare professionals. During the making up of
IT chemotherapy, the visual discrimination provided by distinct spinal equipment will decrease the
likelihood of errors in drug preparation and labelling. Also the locking syringe caps will not be prone
to ‘popping off’ in the manner that the current slip caps are. Only very minor adjustments to the
process of drug preparation will be necessary, in the form of modifications to drug preparation
worksheets. Workshop attendees are, on the whole, supportive of the introduction of an
engineered solution in the form of non-Luer compatible equipment.
(ii)
Spinal Anaesthesia
The PHA process in the context of spinal anaesthesia was more complicated than in the case of IT
chemotherapy. In both anaesthetics workshops, whilst attempting to work through the task analysis
and examine the potential for risks following the introduction of non-Luer equipment, feedback from
anaesthetists rendered the process unnecessary for the reasons outlined below.
The remit of this project is restricted to single-shot spinal injections, and does not extend to include
infusions of anaesthetic drugs. According to consulted clinicians, this does not reflect the
misconnection errors that occur most frequently in anaesthesia practice. In the opinion of
attendees, the potential for error is much greater, and consequences of errors more significant, in
the context of epidural infusions than in that of spinal injections. This is partly because a port
(connected to a catheter which leads into the epidural space) is left exposed on patients for a
19
number of days whilst patients are sent into the more hazardous ward environment. The injection
of unintended (e.g. intravenous) administrations into the epidural space can have significant
adverse consequences. The error consequences in spinal anaesthesia, on the other hand, are
intrinsically low. For instance: if lignicaine (a local anaesthetic used commonly for skin infiltration) is
given intrathecally, a less effective and short-lived block will result; and if bupivicaine (a local
anaesthetic routinely administered intrathecally) is injected subcutaneously, consequences are
minimal.
A further objection that anaesthetists have with the proposed non-Luer system is that, ultimately, it
will not prevent an unintended drug being administered into the spine. Spinal anaesthesia is
prepared by the administering clinician, at the site of administration, just prior to the spinal injection
being given. When the syringe used to administer the IT anaesthetic is attached to a drawing up
needle, it is possible for the anaesthetist to then draw up a drug from any nearby vial or ampoule.
This potential for wrong drug errors will be unaffected by the introduction of non-Luer equipment.
Because the proposed solution applies to bolus injections, rather than to infusion of anaesthetics,
and because the system will still allow anaesthetists to unintentionally draw up unintended
substances, the anaesthetists attending the PHA workshops saw little or no advantage in the
introduction of non-Luer compatible equipment for injections of spinal anaesthetic. In the case of
spinal anaesthesia given preoperatively (outside of obstetrics), or in the context of general pain
management at LGI, the introduction of a system which provides visual distinction between IT and
other syringes that may be present when spinal anaesthesia is being carried out (e.g. those
containing local anaesthetic for skin infiltration, or those for use in aspiration) was seen as
advantageous. In these situations, at LGI, there may be three 10ml syringes on the anaesthetists
trolley which contain either clear liquid, or air. The addition of a distinct non-Luer connector to one
of these syringes would be beneficial when distinguishing between the IT anaesthetic syringe and
other syringes present. In the case of obstetric anaesthesia at the Royal Hallamshire Hospital,
however, different sized syringes for IT, and skin infiltration, anaesthetic agents are already in use.
In this case then, standard practice already provides visual discrimination, allowing the easy
identification of the IT syringe.
Because of the above points, anaesthetists at LGI saw a marginal benefit in the proposed solution.
They proposed a technical solution that is effective in other areas (i.e. IT chemotherapy) which also
provides some improvement to their practice would be tolerated. Anaesthetists attending the
workshop held at the Royal Hallamshire Hospital were less enthusiastic. In the opinion of both
groups of anaesthetists, error reduction efforts in the form of an engineered solution would be
better applied to epidural anaesthesia. Consequently, some degree of clinical resistance to the
introduction of non-Luer equipment for bolus spinal injections in anaesthesia is anticipated.
Clinicians commented that if the changes to equipment for spinal injections were introduced
alongside non-Luer devices for anaesthetic spinal/epidural infusions, they would be more readily
accepted.
The modification of ampoules containing IT anaesthetics could offer an engineered solution to this
problem. The notion of providing ampoules incorporating non-Luer compatible connectors has
already been considered by members of the DHNLSC, in their correspondence with the Canadian
Spinal Injection Safety Syringe (SISS) initiative. This would mean that anaesthetic agents meant
for IT injection could only be drawn up into non-Luer syringes. The NPSA strategy regarding
presentation of medicines in clinical areas should be noted here. In the 2004 risk assessment, the
authors state: “the development and presentation of an increased range of spinal medicine
20
products, in ready to use syringes and infusion bags that can only be administered via a spinal
connector device would further reduce preparation error risks” [5]. The manner in which intrathecal
drugs are presented to clinicians requires further attention, if an engineered solution to
misconnections is to be achieved in procedures other than intrathecal chemotherapy.
(iii)
Spinal Procedures in A&E and Neurology
Non-therapeutic lumbar punctures are routinely carried out in A&E and neurology departments to
enable the diagnosis and monitoring of certain conditions. In neurology, the non-therapeutic lumbar
punctures are often accompanied by a measurement of CSF pressure using a manometer.
Clinicians in each of these fields (based at LGI) were consulted regarding the likely impact of nonLuer spinal equipment their performance of these procedures. In both cases, as no drugs are being
administered, and spinal needle is only intrathecal for a short period of time, there is very little
potential for the injection of inappropriate agents into the spine. It was thought that the introduction
of non-Luer spinal equipment would have no affect on the performance of these procedures,
assuming that the novel equipment is fit for purpose. Potential problems inherent in these
procedures, such as dural puncture headaches or the occurrence of blood in the CSF, would be
unaffected by the implementation of non-Luer spinal equipment. Hierarchical task analyses of a
non-therapeutic lumber puncture, and the measurement of CSF pressure using a manometer can
be seen in Appendix C (ii) and (iii).
6.3.3
Issues surrounding supply and storage of non-Luer equipment
Currently, Luer equipment for spinal and epidural procedures is obtained via several supply routes
– through NHS logistics or other intermediaries (e.g. Squadron Medical for the Sheffield Teaching
Hospitals Trust) or directly from manufacturers (e.g. Helapet Ltd supply Sheffield Children’s
Hospital with syringe caps). The new equipment lines will be suitable for a national contract with
NHS logistics, where NHS logistics will source the equipment from manufacturers, store it in their
regional distribution centers and deliver it to trusts nationwide. The NHS logistics supply route uses
automated ordering, which utilises bar code technology and hand held computer devices. This
system reduces the time needed to process orders, making procurement more simple and less
costly.
Interviews have been conducted with procurement specialists in both the Leeds and Sheffield
trusts. Furthermore, the service development manager of NHS Logistics has been consulted
several times, and has produced a supply chain review on implementing a new range of non-Luer
consumables to the English NHS (see appendix D). Through discussions with procurement
personnel, the following issues relating to procurement and supply have been identified:
(i)
Cost
With less competition in the market, and NPSA recommendations that non-Luer equipment must
be used, there is little incentive for manufacturers to offer the new equipment at reasonable prices.
A clinical procurement specialist in the Sheffield Teaching Hospitals Trust cited the introduction of
non-Luer enteral equipment as an example of such an outcome. In this case, at the time of
interview, there were only two suppliers to the trust, and they were charging high prices for the new
enteral equipment.
21
(ii)
Standards
The nature of the standards for non-Luer compatible small-bore connectors that are produced (by
CEN or ISO) might lead to future complications. If the standards body decides to make one of the
manufacturers’ design solutions a standard, then the design will need to be freely available to all
other manufacturers in order that they may produce equipment to that specification. However, if the
standard agreed upon is more general, and simply states that the equipment must be non-Luer
compatible, then complications might arise. In this eventuality, numerous manufacturers may
produce non-Luer syringes, and needle manufacturers will have to decide which syringe they wish
to align their needles to. This leads to a situation where numerous non-Luer products are available,
some of which are compatible with one-another, some of which are not, making procurement
markedly more complex.
(iii)
Trade Guidelines
If the companies manufacturing non-Luer equipment decided to work independently with hospitals,
and supply directly, this would complicate matters. There are European guidelines for purchasing
contracts that state, when an independent contract of a value of over £100K is established, a
process must be gone through to advertise across Europe and give other manufacturers/suppliers
the opportunity to compete for the business. This process can take up to 6 months and may cause
delays in implementation. If supply is through NHS logistics, however, this process is not
necessary.
(iv)
Equipment Shortages
Stores staff at Sheffield Children’s Hospital stated that occasionally, if high volumes of intrathecal
procedures have taken place, some pieces of equipment have run out. Currently this is not a
problem, because all equipment is Luer, and may be borrowed from other pharmacies in the
hospital or trust. If stocks of the new non-Luer equipment ran out, this borrowing would be more
difficult. However, the move to computerised ordering through NHS logistics, and the ability to
obtain equipment quickly if necessary, means that significant shortages in new equipment will be
unlikely, although do represent a potential risk.
(v)
Storage
In addition to information on storage obtained through discourse with clinical procurement
specialists, further insight into storage issues was obtained during short interviews with three
members of stores staff in the Leeds trust. The new spinal and epidural equipment will be
introduced alongside the current Luer connectors, which will continue to be used for IV
administrations. It may be the case that both types of equipment will be stored in the same place
(i.e. in the same rack or same store room). All stores staff interviewed believed that they would be
able to accommodate the new equipment lines in their stores, and could store Luer and non-Luer
equipment in different areas. Other than this potential complication, the stores staff interviewed
envisaged no problems from a storage point of view. They simply viewed it as a case of adding
another product to the ordering system and having additional space on the shelves for storage.
One area that has not been investigated fully is the storage of equipment of storage in the clinical
area, for instance, in theatre side rooms. This issue was raised at the recent DHNLSC meeting
(19/03/2007, DH Wellington House, London). Interviews with healthcare professionals responsible
22
for the storage of equipment in the clinical areas (e.g. operating department practitioners) are
being organised to address this issue. The interviews will take place during the implementation
study within the Leeds NHS Trust, and findings will be reported to the steering group and funding
body in the Phase 3 report.
6.4
7)
Task 3 Summary
•
Design problems identified during PHA workshops: opacity/translucency of connector, small
diameter of syringe hole, need to twist Prototype 2 syringe to connect, heavy weight of
Prototype 2 connector, provision of Prototype 2 solution in form of adaptor
•
No additional hazards associated with introduction of non-Luer equipment for intrathecal
chemotherapy & only small procedural changes necessary
•
Non-Luer syringes and needles alone NOT an engineered solution to misconnections in
spinal anaesthesia – some degree of clinical resistance anticipated
•
Further consideration of supply and storage in clinical areas is necessary – will take place
during phase 3 implementation studies
Conclusions
From the Prospective Hazard Analysis process, it can be concluded that the implementation of
non-Luer equipment for the use of spinal procedures in haematology and anaesthetics will have a
different impact in each of these care settings. In the case of IT chemotherapy, the implementation
of equipment will solve the problem it is designed to address, without, it would seem, introducing
any new hazards, and requiring only slight procedural modifications. Healthcare professionals in
this area of care are supportive of the technology implementation. In spinal anaesthesia, on the
other hand, clinicians feel that the proposed equipment will not address the problem of wrong drug
errors in their practice, a problem which itself is eclipsed, in their opinion, by the risk of
misconnection during epidural infusions. Because of this misplaced focus, some degree of
resistance to implementation is anticipated on their part.
It is also important to note that clinicians saw several significant drawbacks in the prototype
equipment designs. Fundamental problems related to the opacity or translucency of the non-Luer
connectors (which, it was thought, would obscure the view of CSF flashback); the diameter of the
hole at the end of the connectors (which has implications for the preparation of IT chemotherapy);
and the provision of the Prototype 2 solution in the form of a separable adaptor, which, clinicians
unanimously agreed, does not represent an engineered solution to the problem of spinal
misconnection.
The above issues need to be considered by the DHNLSC and the device manufacturers before the
pre-implementation evaluation is embarked upon. As the research team moves on the next phase
of research, during which issues surrounding implementation of the new equipment will be
examined, further attention shall be given to the storage of the novel devices in the clinical area.
This research project is primarily applied in nature. However, the research team also hope to
develop a methodology for prospective hazard analysis that can be applied in the preimplementation of a range of safety critical devices. The involvement of a range of stakeholders in
a prospective hazard analysis workshop based on previously documented task analyses has
proved to be a very useful way of systematically evaluating the impact of a new device in the
23
various stages of the IT procedure, from preparing the equipment and drugs through to
administration. However, it will also be necessary to develop methods for investigating the wider
implications of the implementation of new devices and this will be the focus of the next phase of
the research.
8)
Acknowledgements
We would like to thank members of the DHNLSC for their support of this project thus far, and for
their informed feedback on the interim and progress reports. We have also received helpful
guidance from Celia Nathan-Marsh and thanks should go to her. Finally, we would like to
acknowledge the contribution of the doctors, nurses and pharmacists who have given up their time
and provided expert advice in all things Luer and non-Luer. In particular, we would like to thank
Martin Dresner, Sally Kinsey, Dominic Bell, and Graeme Smith (Leeds Teaching Hospitals NHS
Trust) and Richard Birks and Jenny Welch (Sheffield Teaching Hospitals NHS Foundation Trust)
for being excellent collaborators throughout Phase 1.
9)
Glossary
Cerebrospinal Fluid (CSF)
CSF is a clear bodily fluid found in the subarachnoid (intrathecal) space within the spinal column
and the ventricular system within the brain. It acts as a buffer for the cortex and provides basic
mechanical and immunological protection to the brain inside the skull. It is necessary to inject
chemotherapeutic agents into the CSF as well as intravenously as these agents cannot penetrate
the blood-brain barrier.
Cross-connection (a.k.a. Misconnection)
Cross connection and misconnection refer to the inappropriate connection of a device to route for
which it is not attended. For instance, the connection of a syringe containing intrathecal medication
to a spinal needle. Such connections are made possible because of the universality of Luer type
connectors. The introduction of non-Luer compatible equipment of spinal procedures is intended to
prevent misconnection at the spinal route.
Epidural
The epidural space is the area of the vertebral column outside of the dura mater (the hard,
outermost layer of the meninges). The epidural space contains loose fatty tissue, and a network of
large, thin-walled blood vessels called the epidural venous plexus. References to ‘epidurals’ in the
report refer to the bolus injection or infusion of local anaesthetics and/or analgesics into the
epidural space.
Intrathecal
The intrathecal space is the space between the thin layers of tissue that cover the brain and spinal
cord. It contains cerebrospinal fluid (CSF), and is also known as the ‘subarachnoid space’. Drugs
may be injected into the CSF contained within the intrathecal space, or a sample of the CSF may
24
be taken, following a lumbar puncture. References to ‘intrathecals’ or ‘IT procedures’ in the report
refer to those which require the insertion of a spinal needle into the intrathecal space, i.e. nontherapeutic lumbar puncture, spinal anaesthesia and intrathecal chemotherapy.
Misconnection
See ‘Cross-connection’ (above)
Spinal
The term ‘spinal’ is used in the present report to refer to intrathecal procedures and the equipment
implicated in their preparation and administration.
10)
References
1.
Berwick D.M. (2001) Not again! BMJ; 322: 247-8.
2.
Reason, J (2000) Human error: models and management. BMJ 320: 768-770.
3.
Toft B. External inquiry into the adverse incident that occurred at Queen’s Medical Centre, Nottingham, 4th January 2001.
Available from http://www.dh.gov.uk/assetRoot/04/08/20/98/04082098.pdf
4.
Woods K. The prevention of intrathecal medication errors. A report to the Chief Medical Officer. Department of Health,
London; 2001. Available from http://www.dh.gov.uk/assetRoot/04/06/50/49/04065049
5.
European Committee for Standardization. (2000) Luer connectors – A report to CEN cheif from the CEN forum task group
“Luer fittings”; CR13825, Brussels.
6.
Cousins, D. & Boult, M. (2004) Risk Assessment of Spinal Procedures with Current Safeguards and with Proposed New
Connector Design Option for the Department of Health. NPSA
7.
Society of Hospital Pharmacists of Australia (2005) High-risk medication alert for
Vincristine injection, Appendix 3: Literature review. December 2005. Prepared by Naomi Burgess, Project Pharmacist, SHPA.
Available from http://www.safetyandquality.gov.au/council/vincristine/vlitera2.pdf
8.
Shepherd D, Steuber C, Starling K & Fernbach D (1978) Accidental intrathecal administration of vincristine. Medical and
Pediatric Oncology, 5 (1): 85-8.
9.
Dettmeyer R, Driever F, Becker A, Wiestler O, & Madea B (2001) Fatal myeloencephalopathy due to accidental intrathecal
vincristine administration: a report of two cases. Forensic Science International, 122 (1): 60-4.
10. Lau G (1996) Accidental intraventricular vincristine administration: an avoidable iatrogenic death. Medicine, Science, and the
Law, 36 (3): 263-265.
11. Williams M, Wallker A, Bracikowski J, Garner L, Wilson K, & Carpenter J (1983) Ascending myeloencephalopathy due to
intrathecal vincristine sulphate. A fatal chemotherapeutic error. Cancer, 51 (11): 2041-7.
12. Dyer C (2002) Junior doctor charged with manslaughter after medical error. BMJ, 322 (7281): 257.
13. Brahams D (1991) Manslaughter and reckless medical treatment. Lancet, 338 (8776): 1189-91.
14. Fernandez C, Esau R, Hamilton D, Fitzsimmons B, & Pritchard S (1998) Intrathecal vincristine: an analysis of reasons for
recurrent fatal chemotherapeutic error with recommendations for prevention. Journal of Paediatric Haematology and
Oncology, 20 (6): 587-90.
15. Ericsson K & Simon H (1980) Verbal reports as data. Psychological Review, 87 (3): 215–251.
16. Kletz T (1986) HAZOP and HAZAN: Notes on the identification of hazards. Rugby. Institution of Chemical Engineers.
17. Reason, J. (1990) Human Error. Cambridge: Open University Press
18. Russell J (2002) Getting into the red: A strategic step for safety. Quality and Safty in Healthcare, 11: 107.
25
11)
Appendices
11.1
Appendix A: Sheffield Hallam University Product Analysis
(Electronically attached)
11.2
(i)
Appendix B: Prospective Hazard Analysis Spreadsheets
IT Chemotherapy (Adult)
(Electronically attached)
(ii)
IT Chemotherapy (Paediatric)
(Electronically attached)
11.3
Appendix C: Hierarchical Task Analyses
(i)
Hierarchical Task Analysis of Spinal Anaesthesia
(ii)
Hierarchical Task Analysis of Non-Therapeutic Lumbar Puncture
(iii)
Hierarchical Task Analysis of Measurement of CSF Pressure
11.4
Appendix D: NHS Logistics Supply Chain Analysis
11.5
Appendix E: SMTL Investigation into Non-Luer Compatible Intrathecal
Connectors
(Electronically attached)
26
SHU Design Evaluation October 2006
Design evaluation of non-Luer compatible
intrathecal connectors
Professor P M Chamberlain
Dr P J Walters
Faculty of Arts, Computing and Engineering Sciences
Sheffield Hallam University
October 2006
Executive Summary
In addition to usability issues, the Sheffield Hallam University (SHU) team were keen to further
investigate compatibility of the prototypes with Luer connectors, following Surgical Materials
Testing Laboratory (SMTL) reports that some of the cross connections achieved by healthcare
professionals could not be recreated by the SMTL technical team.
(i)
Misconnectability
The SHU team concludes that both Prototype 1 and Prototype 2 non-Luer compatible connection
systems could prevent a syringe with a standard male Luer connector being wrongly attached to a
spinal needle. This is because in both prototypes the aperture of the female non-Luer fitting is
smaller than the narrow end of a standard male Luer tapered connector, so male and female will not
mate. As an exception to this, it proved possible to force the male Luer connector of a standard
syringe into the female connector of a Prototype 1 epidural needle. However, in this case the forces
required to misconnect exceeded those of normal use.
(ii)
Usability
Regarding Prototype 1, the SHU team concur with feedback obtained during SMTL usability
evaluations. We too found the Prototype 1 devices small and fiddly, with a harsh grip area making
the connectors uncomfortable to use. However, regarding the small size of the Prototype 1
connectors, we suggest that patient comfort should be taken into account. Larger connectors could
be heavy when attached to the patient, leading to discomfort. The Prototype 2 male connector is
significantly larger than Prototype 1, providing a good-sized grip area. However, the female fitting
on the Prototype 2 spinal needle lacks adequate grip provision - a sharp flange making the device
uncomfortable to handle.
1
SHU Design Evaluation October 2006
(iii)
Equipment Identification
This report also contains a discussion on the differentiation of equipment used for delivery of drugs
by different routes. The authors express misgivings about the use of colour coding in this
differentiation, and propose that haptic (shape) coding may be prove valuable in this context.
1.0
Introduction
This report presents the findings of a critical evaluation of prototype non-Luer compatible medical
connectors intended for spinal use. Non-Luer compatible connectors have been proposed as a
design solution to help prevent potentially-fatal "misconnection errors" in the administration of
anaesthetic, oncological and other drugs to hospital patients. A number of fatalities have occurred
because patients have received intravenous drugs via the spinal route by mistake.
The design evaluation forms part of an interdisciplinary study commissioned by the Department of
Health Patient Safety Research Programme. The study, led by researchers at Leeds University
Institution of Psychological Sciences, aims to investigate 1) potential hazards associated with the
implementation of the prototype non-Luer spinal connectors 2) the usability of the connectors in
simulations of practice 3) barriers and levers to successful implementation of the non-Luer spinal
connector.
The design evaluation is intended as a preliminary investigation into the technical, functional and
ergonomic characteristics of the non-Luer connectors, together with associated devices contained
within prototype intrathecal/epidural kits. The aim is to identify any potential problems or issues
with the performance and usability of the new devices, prior to more extensive task analysis and
user evaluation phases which will take place later in the study.
The evaluation was undertaken by Professor Paul Chamberlain, Professor of Design in the Faculty
of Arts, Computing and Engineering Sciences at Sheffield Hallam University, assisted by Dr Peter
Walters, a Researcher in Design, also at Sheffield Hallam University. Chamberlain has worked
widely within the medical and healthcare technology field, and has recently undertaken research
into the safety and usability of medical devices, funded by the DoH Health Technology Devices
Programme and a leading manufacturer, B Braun. He is a member of the external advisory group
for the National Patient Safety Agency, and the European Standards Committee (CEN) working
group for medical connectors. Walters' doctoral research investigated methods and outcomes of
"human-centred" design processes, and included practical case studies from within the area of
medical product and packaging design.
2
SHU Design Evaluation October 2006
It was originally intended that the design evaluation would be undertaken in parallel with a
technical evaluation into the physical performance of the connectors, carried out by the Surgical
Materials Testing Laboratory (SMTL). However, due to the late arrival of the prototype epidural
kits, the design evaluation did not commence until after the SMTL technical evaluation had been
completed. Because of this, the Sheffield team had the opportunity to review the findings of the
SMTL evaluation prior to undertaking their own investigations. This provided a useful starting
point and helped to inform the design evaluation.
The section which follows summarises the SMTL technical evaluation, drawing attention to some
problems and issues that were found to be evident in the design of the prototype connectors, and
which went on to become a focus for further investigation within the design evaluation.
2.0
Summary of the technical evaluation of non-Luer compatible
intrathecal connectors carried out by the Surgical Materials Testing
Laboratory
The Surgical Materials Testing Laboratory (SMTL) was commissioned to undertake a technical
evaluation of the non-Luer compatible connectors. The following non-luer connectors were
evaluated: Prototype 1, Prototype 2 and Prototype 3. Testing was based on the European Standard
for Luer Lock fittings (BS EN 1707:1997). Although the dimensions of the non-Luer connector
would be different to the standard Luer fitting, the European Standard was adopted as a benchmark
for the tests since the same level of performance would be required from the new designs
(SMTL report p 3).
The SMTL study included tests designed to evaluate the physical performance of the prototype
connectors. These included: measurement of the connectors' external dimensions; measurement of
assembly and disassembly forces; investigation of resistance to forced separation and overriding of
the threaded connection; liquid and air leakage tests; and visual/microscope inspection for signs of
stress cracking after the connector components were assembled for 48hrs at 20±5°.
In addition, the SMTL undertook usability testing to evaluate the ease of assembly and noninterchangeability of the prototype connectors. 11 healthcare professionals were asked to attempt to
(mis)connect the prototype non-Luer connectors to a range of 20 Luer connector devices currently
used in the NHS. The participants' general comments relating to the ease of use of the new
connectors were also recorded. Finally, tests were carried out to see if it was possible to inject a
3
SHU Design Evaluation October 2006
bolus liquid through each of the new non-Luer connectors when wrongly attached or partiallyattached to a standard Luer connector.
In the assembly and leakage tests, the Prototype 1 connector system performed well, achieving 10
out of 10 in all tests. Prototype 3 performed poorly on air leakage (4 out of 10), but passed 9 out of
10 in the liquid leakage tests and 10 out of 10 in the other tests. Prototype 2 passed 6 out of 10 in
the liquid leakage and air leakage tests, 9 out of 10 in the separation force tests, and 10 out of 10
for the other tests.
When the Prototype 1 connectors were examined for signs of stress cracking after 48hrs assembly,
no cracking was observed on male connectors, but some light cracking occurred on females. Slight
surface abrasions were also noted on mating surfaces, which may have been due to
assembly/disassembly forces and friction/stiction due to the connector material (see below). For the
Prototype 3 connectors there were no signs of stress cracking, but the presence of moulding flash
on components was noted. The Prototype 2 connectors showed no obvious deformation or damage,
however the colour/opacity of the test component materials meant identifying stress cracking or
other surface abnormalities was virtually impossible.
SMTL noted that the plastic material from which the Prototype 1 connector is made tends to bind
to itself, resulting in some difficulty loosening the rotating collar - following the 48hr assembly
period, excessive force was required to separate the connectors (SMTL report p16).
In user trials, some misconnections were shown to be possible: for example a male non-Luer could
be fully or partially attached to a female Luer connector and, in the case of Prototype 3, to a male
Luer connector.
In the epidural case, the spinal needle normally has a female connector. SMTL reported that in user
testing, some users could attach male Luer connectors to female non-Luers. This presents the
possibility of misconnection occurring if a syringe with a male Luer connector could be attached to
a spinal needle having a female non-Luer connector. However, the SMTL technical team reported
that they were unable to replicate these cross connections.
In tests to observe whether a bolus injection could be passed through a Luer/non-Luer cross
connection, where a male Prototype 1 non-Luer was slipped into a female Luer, some or all of the
bolus could be passed through the cross connection depending on the orientation of the connector
components. Where a Prototype 3 male non-Luer was attached to a male Luer with a tight friction
fit, the bolus was passed entirely from a syringe with male Prototype 3 connector into tubing with
4
SHU Design Evaluation October 2006
male Luer. For the Prototype 2 connectors, a number of full and partial misconnections were
observed, and in some cases, a proportion of the bolus could be passed, with some leakage
occurring.
SMTL also noted comments that were made by the healthcare practitioners who participated in the
user trials. For example, regarding the Prototype 1 system, users commented that the connectors
were: "very hard to disengage. Feels flimsy ... Harsh feel which irritates fingers when trying to
disengage. Not user friendly ... small and fiddly ... there are stiction issues i.e. can not disengage
connectors easily." They noted that the Prototype 3 connector required "Lots of twists before fully
engages." and also "Male connector soft enough to cross connect." Finally, for the Prototype 2
connectors, users commented that the "plastic seems very soft which makes the male connector
easy to cross connect ... little lugs are easy to break".
From the findings and conclusions of the SMTL report, the Sheffield team noted that whilst some
participants in the SMTL user trials had reportedly been able to connect a male Luer connector to
female non-Luer, the SMTL technical group had been unable to replicate these cross connections
(SMTL report p 30). Because of the apparent discrepancy between misconnections the users could
make and those the SMTL could replicate, and also because misconnections of this sort could
represent a significant hazard - an intravenous syringe with a male Luer could be attached to a
spinal needle having a female non-Luer - the Sheffield team undertook further investigations into
the "misconnectibility" of the non-Luer connectors.
The Sheffield team also went on to investigate usability issues that were clearly evident in
comments from participants in SMTL user trials. Two non-Luer compatible connector kits were
evaluated: those of Manufacturer 1 and Manufacturer 2, the Manufacturer 3 kit having been
withdrawn from the evaluation.
3.0
Prototype 1
3.1
Prototype 1 Misconnectibility
Attempts were made to attach various devices with male Luer connectors (syringes, 3-way valves,
tubes) to the female non-Luer connector of a Prototype 1 spinal needle. Because the narrow end of
the male Luer taper is slightly larger than the aperture belonging to the female non-Luer (1) the two
components would not mate when pushed together by hand with light to moderate force. Yet with
the application of a significantly greater load - by pushing and twisting on a large syringe which
afforded good grip and substantial leverage - it was found to be possible to force a male Luer into a
female non-Luer. Although the thin wall of the female component fractured, the mating
5
SHU Design Evaluation October 2006
components still held together. However, it should be noted that in this case the forces required to
misconnect were somewhat brutish, and as such would most likely exceed those of normal use.
Figure 1
A syringe with a male Luer connector was forced into the non-Luer connector of a
Prototype 1 epidural needle
Attempts were also made to attach a Prototype 1 syringe with a male non-Luer connector to devices
with female Luer connectors. It was found that a Prototype 1 syringe could be attached fairly
securely to a needle with a female Luer connector. Because the material from which the female
Luer was made was softer and more flexible than that of the Prototype 1 male, the thread on the
collar of the Prototype 1 was able to bite into the outside of the female such that the two
components held together. Fluid could then be passed from the syringe and through the needle
with some leakage.
1
The narrow end of male Luer taper is approximately 4 mm diameter.
The aperture of female Prototype 1 non-Luer is approximately 3.6 mm diameter.
Figure 2
A Prototype 1 syringe with male non-Luer connector was attached to a needle
with a female Luer connector.
6
SHU Design Evaluation October 2006
The fact that a supposedly incompatible syringe and needle could be connected together in this way
presents the possibility of misconnection errors occurring such as those identified by the American
Joint Committee on Accreditation of Healthcare Organisations (2006), in which 'epidural solutions
(intended for epidural administration) [were] connected to peripheral or central IV catheters.' (2)
Figure 3
When connecting up tubes and devices, users may naturally hold the
devices rather than the connectors themselves. The extra leverage which may be
afforded when gripping and turning larger items mean it may be possible to forcibly
connect incompatible tubes and devices.
3.2
Prototype 1 Usability
In usability studies undertaken by SMTL, users commented that they found the Prototype 1
connectors small and fiddly, and that they could feel harsh to the fingers. The Sheffield team noted
that for some items in the Prototype 1 system, the grip area was quite small - eg 7mm grip length
on the short needle, compared with 13mm on the longer needle. Those items with shorter grip area
appeared to be particularly fiddly, and also the four longitudinal ribs on the grip area felt quite
sharp when gripped and turned between thumb and forefinger. However, this sharp feeling may be
reduced when users wear surgical gloves.
7
SHU Design Evaluation October 2006
It should also be noted that, whilst users described the Prototype 1 connectors as small and fiddly,
there may arguably be advantages in making such components as small as is practicably possible,
to prevent them from being too heavy and bulky, in order to reduce discomfort to the patient when
attached to the body. Therefore a compromise may need to be reached between what healthcare
staff find usable, and what is comfortable for the patient.
short grip length
Figure 3
Prototype 1 - small and fiddly
The shorter grip length on some of the Prototype 1 connectors makes them small and fiddly to use.
Also some of the edges of the grip area feel quite sharp, however this is less evident when wearing
surgical gloves
4.0
Prototype 2
4.1
Prototype 2 Misconnectibility
The Sheffield team found it impossible to connect a syringe with a standard male Luer connector to
a spinal needle with a female Prototype 2 non-Luer connector. The diameter of the aperture of the
female Prototype 2 connector is significantly smaller than the narrow end of the tapered male Luer
fitting (3) making it impossible for the two to mate. Also, the wall thickness of the Prototype 2
female fitting was found to be greater than that of the Prototype 1 female, making it stronger.
Attempts to forcibly connect a standard male Luer syringe were resisted by the Prototype 2 female
fitting.
The female non-Luer fitting of the Prototype 2 spinal needle is manufactured in a transparent, rigid,
polycarbonate-like plastic material. However the Prototype 2 male connector is moulded from a
softer, flexible plastic. Because the material is compliant, it was found to be relatively easy to
attach a syringe with a Prototype 2 male connector to a needle with a standard female Luer fitting.
As with the Prototype 1 system, this presents the possibility of misconnection. For example, an
8
SHU Design Evaluation October 2006
intrathecal drug contained within a syringe with a Prototype 2 male connector could be wrongly
administered to the patient through an intravenous needle with a standard female Luer fitting.
Figure 4
Prototype 2 male connector
Full and partial misconnections to needles with female Luer connectors
3
The narrow end of male Luer taper is approximately 4 mm diameter.
The aperture of female Prototype 1 non-Luer is approximately 3.3 mm diameter.
In the Prototype 2 intrathecal kit, a standard syringe with a male Luer connector is made non-Luer
compatible by attaching a Prototype 2 male fitting which screws into the thread of the male Luer.
Once fitted, a ratchet mechanism incorporated into the Prototype 2 connector prevents it being unscrewed again, the intention being that once converted, the non-Luer compatible syringe cannot be
returned to its standard Luer state. However, it was found that with moderate force the Prototype 2
male connector could be removed by pulling it straight out of the threaded Luer fitting rather than
unscrewing it - the material of the Prototype 2 being sufficiently soft for the thread to flex and jump
out. This returns the syringe to a standard Luer state.
9
SHU Design Evaluation October 2006
Figure 5
The Prototype 2 male non-Luer connector can be pulled out of the thread
of the syringe, returning it to its standard Luer state.
Figure 5
The outer grip/ cover of the Prototype 2 male non-Luer can be pulled off
to reveal the internal ratchet mechanism.
4.2
Prototype 2 Usability
The male Prototype 2 connector is significantly larger than the equivalent Prototype 1 fitting, and
so appears to be less fiddly to handle. However, in the sample kit provided for evaluation, the
female connector on the Prototype 2 spinal needle appears to lack any adequate provision for
gripping, and the sharp edges of the flange situated towards the bottom of the connector make it
awkward and uncomfortable to use. Here the Sheffield team questioned whether an additional grip
component, or a pair of attachable wings, was missing from the Prototype 2 kit.
10
SHU Design Evaluation October 2006
Figure 6
The Prototype 2 needle lacks adequate provision for gripping the device,
in particular the flange at the lower end of the plastic fitting makes it
awkward and uncomfortable to use.
Furthermore, in the design of the Prototype 2 connector system, there is no obvious visual
similarity, coding or cue to indicate the relationship of compatibility between the syringe connector
and the spinal needle, to inform the user that the two belong together and can therefore be
connected. Furthermore, in the Prototype 2 system, the male syringe connector is opaque and
coloured purple, whilst the connector fittings on the intrathecal filter are opaque yellow, and the
spinal needle connector is clear transparent. The Sheffield team were unsure of the significance, if
any, of this difference in colour, which could clearly cause confusion in use. Also, in terms of
visual appearance, there is little to distinguish the Prototype 2 epidural needle from a standard Luer
11
SHU Design Evaluation October 2006
needle, which could also cause confusion.
When compared to the Prototype 2 kit, the Prototype 1 connectors appear more distinctive in terms
of colour and, to some extent, shape, which helps to provide a visual relationship between the
compatible components in the Prototype 1 system.
5.0
Identification of connectors - colour and shape coding
A mechanically non-interchangeable connection system could make misconnection errors
physically impossible. However, concerns exist that the use of such a system could create further
problems for healthcare staff (4). For example, it could lead to problems identifying the correct
connector, especially in time-pressured situations.
The ergonomists Sanders and McCormick (1993) note that colour may be employed as an effective
means of coding items, to aid identification and selection. However, they also point out that colour
is not universally useful as a coding system (5). Also, Wilson and Corlett (1995) assert that '...Care
must be taken in the use of colour as it can increase the potential for human error.' (6)
To aid connector identification, colour coding may be used to distinguish between different
delivery routes (eg between intravenous, intrathecal, enteral etc) and/or different drug types. Colour
coding and other labelling systems are already employed in hospitals to assist in the identification
of drug delivery lines. For example, guidelines for good practice in the management of continuous
epidural analgesia state that:
'... epidural infusion lines should be clearly identified and this might include the use
of coloured tubing and labels attached near to any connector. It would be advantageous to
have a universally agreed standard colour for epidural infusion lines but at present tubing
colour varies from place to place.' (7)
The guidelines go on to state that in many centres the colour red is used for arterial lines, blue for
venous and yellow for nerve block. However, the absence of an agreed standard for colour coding
means that problems could arise, for example, if staff move from one hospital to another where
different colour coding systems are used. Furthermore, the Royal College of Nursing (2005)
confirm colour coding is not standardised for drug infusion therapy, and also report that different
manufacturers employ different colour code systems (8). The lack of agreed standards clearly adds
a further layer of complexity to the problem of connector identification.
12
SHU Design Evaluation October 2006
A number of other concerns have been raised regarding the use of colour coding. For example, the
American Joint Commission on Accreditation of Healthcare Organisations (2006) suggests that the
use of colour coding '...can lead users to rely on the colour coding rather than assuring a clear
understanding of which tubes and catheters are connected correctly to which body inlets.' (9)
Problems with colour identification may also occur if the level of lighting on a hospital ward is low.
A report to the Committee on the Safety of Medicines (10) draws attention to the fact that the
appearance of colours can vary depending upon lighting conditions, and the ergonomist Helander
(2006) states that colour coding is only effective in a well-illuminated environment (11).
Scientific studies into the application of colour coding for controls and graphical displays are predated by the extensive investigations into colour conducted by Johannes Itten and Josef Albers,
both Professors at the famous Bauhaus School of Design in Germany (1919 - 1933). In his 1961
work The Art of Color (12), Itten included a detailed technical discussion on contrasting colours,
whilst Albers' extensive experimental studies, described in Interaction of Colour (1963),
demonstrate that the interpretation of any colour depends on its environment. For example,
identical objects of the same colour can appear differently depending on the colour of the
background on which they are presented (13).
It should also be noted that some individuals are colour blind, and so may have difficulties
distinguishing between different colours. Furthermore, in guidelines on the use of colour within
information display graphics, NASA recommend that colour coding should not used for the
identification of small items (14), a point which is clearly significant bearing in mind the small size
of connector components. Also, when in use, clear sight of the connectors may be obscured by the
patient, or the user's own hands, or items such as bandages, bedclothes, surgical tape, or other
medical devices.
Rather than relying solely on colour as a means of identification, items may be coded by shape. For
example, Norman (1988) stresses the importance of designing product controls that 'look and feel
different', especially in safety critical applications (15). He gives the example of a control panel for
a nuclear power plant. Control-room operators have modified similar-looking switches by fitting
them with different beer-pump handles to prevent misidentification (figure 7).
13
SHU Design Evaluation October 2006
Figure 7
Control switches from a nuclear power station, where the handles have
been modified by fitting them with different beer pump handles to prevent
misidentification (source Norman, 1988)
Research carried out by the US Air Force investigated the benefits of 'shape coded' aircraft controls.
In one study, Jenkins (1947) found that blindfolded pilots could identify these specially shaped
control knobs using only the sense of touch (Figure 8).
Figure 8
Shape-coded Aircraft control knobs (16)
Figure 9 shows sketches of a second set of control knobs, proposed by the US Air Force System
Command (1980). In this case, the knobs have been designed to symbolically represent the
intended function of the aircraft controls: e.g. the landing flap control is shaped like a wing, and the
landing gear control is shaped like a wheel. Although the use of symbolic shapes appears quite
crude, it is considered to be advantageous as it makes it easier for pilots to learn the functions of the
different controls and reduces the likelihood of error (17).
14
SHU Design Evaluation October 2006
Figure 9
Symbolic shape-coding of aircraft controls
These examples indicate the potential benefits of an identification system that is based on the use of
contrasting shapes. Researchers based at Sheffield Hallam University and the University of Leeds
have been investigating the application of "shape coding" to assist in the identification of medical
connectors (18, 19). Here, visual and tactile cues - contrasting shapes and surface textures - are
applied to the outside surface of prototype connectors, in order that they might be identifiable by
touch as well as sight. Early findings from this research indicated that users could select and match
prototype connector components by touch alone, with few errors, even when wearing surgical
gloves. Of course, the research does not advocate healthcare staff performing procedures without
looking at what they are doing, but it does suggest that touch might be effectively employed in
support of vision.
The study clearly points to opportunities to engage in further research, for example, to investigate
the effectiveness of an identification system combining both colour and shape coding, applied to
physical objects of a size suitable for medical connectors.
Much recent research into the application of colour coding appears to have focussed on 2dimensional graphics, and in particular, on screen-based applications, such as computer interfaces
and air-traffic control displays (20, 21). However, when considering the effective application of
colour coding in the design of physical objects, there is clearly a requirement to investigate the
implications of size, 3-dimensional shape, texture, material, shadows, surface finish and
translucency, and to understand the combined impact of these different physical characteristics.
15
SHU Design Evaluation October 2006
6.0
Conclusions
From the findings of the design evaluation described in this report, it may be concluded that both
Prototype 1 and Prototype 2 non-Luer compatible connection systems could prevent a syringe with
a standard male Luer connector being wrongly attached to a spinal needle. This is because in both
Prototype 1 and Prototype 2 connectors the aperture of the female non-Luer fitting is smaller than
the narrow end of a standard male Luer tapered connector, so male and female will not mate. As
an exception to this, it proved possible to force the male Luer connector of a standard syringe into
the female connector of a Prototype 1 epidural needle. However, in this case the forces required to
misconnect would most likely exceed those of normal use.
The Sheffield team found that it was possible to connect both Prototype 1 and Prototype 2 male
connectors to standard female Luer devices such as intravenous needles. This presents the
possibility of misconnection errors, for example, in which the male "non-Luer" connector of an
epidural syringe or delivery line could be wrongly attached to an intravenous needle with female
standard Luer fitting. This is one of a range of possible misconnection errors recently reported by
the American Joint Committee on Accreditation of Healthcare Organisations (2). They cite a
United States Pharmacopeia database listing more than 300 misconnection errors, including such
cases as: an oxygen tube being connected to a needless intravenous port; an enteral feeding set
being connected to a central venous catheter; a blood pressure insufflation tube being connected to
a needleless intravenous port. The American report serves as a reminder that the problem of
misconnection errors is not confined to the maladministration of intravenous drugs via the spinal
route, and that a design solution covering all routes/delivery lines may therefore be required (see
also 22).
(22)
The National Patient Safety Agency (NPSA) has identified cases in which the epidural
anaesthetic bupivacaine was given to patients intravenously by mistake. They note that
bupivacaine can cause cardiac arrest if administered intravenously. The NPSA highlight a case in
which a female patient at the Great Western Hospital in Swindon died after an epidural was injected
into her arm. (NPSA Safer Health Care 15 - 21 June 2006).
A number of issues were identified regarding the usability of the prototype non-Luer connectors.
Here users participating in the SMTL evaluation commented that the Prototype 1 connection
system was small and fiddly, and therefore wasn't user friendly - the grip area felt harsh when
gripped between finger and thumb, making the connectors awkward and uncomfortable to use. The
Sheffield team concurred with these findings but also noted, regarding the small size of the
16
SHU Design Evaluation October 2006
Prototype 1 fittings, that patient comfort should also be taken into account - larger connectors could
be heavy and bulky when attached to the patient, leading to discomfort.
Compared to the Prototype 1 fittings, the male Prototype 2 syringe connector is significantly larger
and the grip area is of a good size. However, the female fitting on the Prototype 2 spinal needle
lacks adequate grip provision - a sharp flange making the device uncomfortable to handle. Here the
Sheffield team wondered if an addition grip/winged component might be missing from the
Prototype 2 kits provided for evaluation.
The final area to be discussed as part of the design evaluation was the requirement for an effective
identification system to distinguish between different delivery routes, in order to help hospital staff
select and use the correct connectors, especially in time-pressured situations. Colour coding has
been proposed as a means to identify tubes and devices for different delivery routes. Whereas
colour coding has been employed in other areas of healthcare, for instance the International Colour
Coding System for Syringe Labelling used in Anaesthesia (24), a number of problems have been
identified with colour as a means of identification in this context. These include: a) the absence of
an agreed standard for colour coding of delivery routes, and the fact that different manufactures
appear to employ their own colour coding systems, both of which may cause confusion in use; b)
the appearance of colours can vary depending on lighting conditions and background colour, so
colour coding could be read differently depending on the light level of a hospital ward; c) some
people are colour blind; d) the small size of connector components may prove problematic - for
example, NASA guidelines warn against applying colour coding to small items.
Rather than relying solely on colour as a means of identification, researchers at Leeds and Sheffield
Hallam Universities have pointed to the potential application of shape coding in this context. To aid
connector identification, visual and tactile cues - in the form of contrasting shapes and surface
textures - could be applied to the outside surfaces of connectors. Clearly, further research is
required to investigate the effectiveness of a coding system for medical connectors employing a
combination of colour, shape and texture, in order to determine whether such a system could
improve usability and help prevent error.
17
SHU Design Evaluation October 2006
6.0
Summary and further recommendations
1
As part of the proposed task analysis, video may be used to record participants' hand
movements as they attempt connection tasks. Analysis of the video footage may provide
valuable insights into the use and usability of the prototype connectors and associated
devices.
2
As well as evaluating the effectiveness of the new kits in reducing the risk of
misconnection, the task analysis should seek to obtain qualitative feedback from
healthcare professionals on usability issues, for example: affordance - do the prototype
male and female connectors look and feel like they should go together? ease of connection
- are the connectors fiddly, awkward or uncomfortable to use?
3
In addition to considering misconnections which could lead to the maladministration of
intravenous drugs via the intrathecal route, the study should also consider the wider range
of possible misconnections errors, such as those identified by the American JCAHO (2).
4
Whilst simulated clinical scenarios can go some way to recreate the actual conditions of
use, clearly such scenarios cannot truly capture all aspects involved in the treatment of real
patients, for example, the psychological stresses encountered when dealing with clinical
emergencies (23). This should be taken into account when using simulation for the
purposes of product testing.
5
Careful consideration must be given to the appropriateness of colour coding in this
context, in particular taking into account the fact that perception of colours varies under
different lighting conditions and background colours, and the small size of connector
components.
6
In future, further research may be undertaken into the potential development of an
identification system for medical connectors which combines colour and shape coding,
with the aim of making it safer and easier to select and use the correct connectors in
complex, time-pressured situations.
18
SHU Design Evaluation October 2006
References
(2) Joint Committee on Accreditation of Healthcare Organisations (2006) Tubing misconnections a persistent and potentially deadly occurrence. Sentinel Event Alert: Issue 36 April 3, 2006
(4) Bickford-Smith, P. (2001) Designing safer medical devices needs financial and political
support in British Medical Journal No 322 p 548.
(5) Sanders, M. and McCormick, E. (1993) Human Factors in Engineering and Design
International Edition, McGraw Hill pp 125 - 127
(6) Wilson, J. and Corbet, E. (1995) Evaluation of Human Work Second Edition, Taylor and
Francis p 401
(7) Royal College of Anaesthetists et al. Good practice in the management of continuous epidural
analgesia in the hospital setting. November 2004
(8) Royal College of Nursing Standards for infusion therapy. November 2005
(9) American Joint Commission on Accreditation of Healthcare Organisations Tubing
misconnections - a persistent and potentially deadly occurrence. Sentinel Event Alert: Issue 36
April 3, 2006
(10) Report to the Committee on the Safety of Medicines from the Working Group on Labelling and
Packaging of Medicines July 2001 Medicines and Healthcare products Regulatory Agency
(11) Helander, M. (2006) A guide to Human Factors and Ergonomics Second Edition, Taylor and
Francis, London and New York
(12) Albers, J (1963) Interaction of Color revised and expanded edition (2006) Yale University
Press, New Haven and London).
(13) Itten, J. (1961) The Art of Colour Van Nostrand Reinhold Company
(14) NASA Color Usage Research Lab Guidelines for colour discrimination and identification
http://colorusage.arc.nasa.gov/ (accessed 13 October 2006)
19
SHU Design Evaluation October 2006
(15) Norman, D. A. (1988) The Psychology of Everyday Things published by Basic Books, New
York
(16) Jenkins, W. O. (1947) The tactual discrimination of shapes for coding aircraft type controls in
Fitts P. M. (ed) Psychological research on equipment design, research report 19, US Army Air
Force Aviation Psychology Program
(17) Air Force System Command (1980) Design Handbook 1-3, Human Factors Engineering 3rd
Edition US Air Force
(18) Walters, P. Chamberlain, P. and Press, M. (2003) In Touch: an investigation of the benefits of
tactile cues in safety- critical product applications in the proceedings of the Fifth European
Academy of Design Conference, University of Barcelona, April 2003
(19) Chamberlain, P. Gardner, P. Lawton, R. and Green, B. (2006) Shape of Things To Come in the
proceedings of EuroHaptics 2006, Paris, July 2006
(20) Van Laar, D. and Deshe, O. (2002) Evaluation of a visual layering methodology for colour
coding of control room displays Applied Ergonomics 33 pp 371-377
(21) Ahlstrom, U. and Arend, L. (2005) Colour Usability on Air Traffic Control Displays in the
proceedings of the Human Factors and Ergonomics Society 49th Annual Meeting 2005
(22) National Patient Safety Agency (2006) 200 epidural errors reported after three women die
Safer Health Care 15 - 21 June 2006
(23) Kneebone, R. L. Scott, W. Darzi, A. Horrocks, M. (2004) Simulation and clinical practice:
strengthening the relationship Medical Education 38 No. 10 pp 1095-102
(24) The Royal College of Anaesthetists. Syringe labelling in critical care areas, Bulletin 19, May
2003. (http://www.rcoa.ac.uk/docs/B19_Syringe_Labelling.pdf)
20
HTA No.
PRESCRIPTION
Drugs prescribed by C or SR (or staff grade doc)
1
1.1
IT Chemo chart signed by prescribing individual (or staff
grade doc)
1.2
Action
Initiator
Activity
C or SR
C or SR
Action
Taker
C or SR
C or SR
1.3
Drug route and administration clearly printed on chart
C or SR
(use 'chemocare' computer system). In emergency - can
be annotated by C
C or SR
1.4
Chart printed onto blue paper portrait (all other chemo =
landscape)
C or SR
Pht
1.5
Pht checks prescription
Pht
Pht
Potential Error
Potential Error Type
1.Incorrect drug chart choice (e.g.
cytarabine instead of methotrexate)
2. Incorrect patient label
3. Platelet count inadequate
4. Drugs prescribed by unauthorised
medical staff (anyone not on register)
1. Input - slip/lapse or mistake.
Input - slip/lapse or mistake.
Decision - slip/lapse or mistake.
Decision - violation
1.Incorrect drug chart choice (e.g.
cytarabine instead of methotrexate)
2. Incorrect patient label
3. Platelet count inadequate
1. Input - slip/lapse or mistake.
Input - slip/lapse or mistake.
Decision - slip/lapse or mistake.
1.Incorrect drug chart choice (e.g.
cytarabine instead of methotrexate)
2. Incorrect patient label
3. Platelet count inadequate
1. Input - slip/lapse or mistake.
Input - slip/lapse or mistake.
Decision - slip/lapse or mistake.
Decision - Violoation
Potential Consequence of Error
2.
1. Potential recovery by C or PHt at 2.1.1.
If not recovered, wrong IT drug made up
and given.
2. Drugs
given to wrong patient.
3. Bleed in
CSF.
4. Illegal
prescription.
2.
1. Potential recovery by C or PHt at 2.1.1.
If not recovered, wrong IT drug made up
and given.
2. Drugs
given to wrong patient.
3. Bleed in
CSF.
3.
4.
3.
2.
3.
1.6
Out of hours prescriptions must be must be authorised
by C
C
C
Authorised by other than C
1.7
Create worksheet for each patient
Ph or T (IT
trained)
Ph or T (IT
trained)
1- 3 = Input (misread), Output (incorrectly
1. Wrong patient,
entered) - slip/lapse or mistake (could also
2. Wrong drug,
be violation but would need to be malicious).
3. Wrong route of admin.
Worksheet can be printed correctly, but
filled out inaccurately = mistake in labelling
HTA No.
2
2.1
Activity
Action
Initiator
Action
Taker
Potential Error
Potential Error Type
Potential Advantages/Disadvantages with
Non-Luer
1. Potential recovery by C or PHt at 2.1.1.
If not recovered, wrong IT drug made up
and given.
2. Drugs
given to wrong patient.
3. Bleed in
CSF.
Potential recovery at 1.7 or 2.1.1
1. Patient given inappropriate medication.
2. Patient given inappropriate medication.
3. IV/IT error. All above have potentially
major consequences, however, potential
recovery at 2.2.2, 2.2.3, 2.5.1
Potential Consequence of Error
Potential Advantages/Disadvantages with
Non-Luer
DRUG PREPARATION
MAKING
2.1.1 Put together tray ensuring correct no. of vials, drug, no.
of syringes, filter size
Ph/T
Ph/T
2.1.2 Cytotoxic drug drawn from vials into syringe
Ph/T
Ph/T
Wrong strenth vial (Methotrexate: 50mg in
2ml or 5mg in 2 ml. Cytarabine 100mg in
5ml or 500mg in 5ml).
Input - slip/lapse or mistake. Decision violation (would need to be malicious)
10 x (Methotrexate) or 5 x (Cytarabine)
drug error
NON-LUER: IT syringes will be distinct from
IV - less chance of picking wrong syringes
thereby minimising input slip/lapse or mistake
errors
2.2
2.1.3 Drug inserted (through 0.2 micron microbiological filter
[max 4 at a time]) into individual [10ml or 1ml]) syringes
for each patient. Note: Depocyte not filtered
Ph/T
Ph/T
Drug not filtered/filter not working.
Input - slip/lapse or mistake.
Particulate matter in syringe - injected into With current NON-LUER prototypes could be
CSF
difficult to see when syringe due to
opaque/translucent connector on end of
syringe
2.1.4 Syringe cap attached to each syringe (should be
provided separately - not connected)
Ph/T
Ph/T
Syringe cap comes off (as Luer is slip
connection, not lock);
Output - slip/lapse or mistake (insufficiently
secured)
Need to re-make IT administration
2.1.5 Empty vials placed in sealable bag
Ph/T
TECHNICIAN CHECKS
2.2.1 Vials counted
2.2.2 Vials checked (name, strength and volume of drug, batch Ph/T
number, expiry date, manufacturer and appropriateness
for intrathecal delivery checked)
Ph/T
2.2.3 Syringes checked against worksheet to ensure correct
drug & volume being given and no impurities present
2.3
LABELLING
2.3.1 Labels checked against prescription and contents of
syringe
2.3.2 Label attached to each syringe (along measurement
markings)
2.5
Ph/T
2.3.2 Labelled syringes placed in bags and sealed
2.3.3 Label attached onto sealed bag
2.3.4 Label attached to worksheet
PHARMACIST CHECKS
NON-LUER: IT syringes will be distinct from
IV - less chance of picking wrong syringes
thereby minimising input slip/lapse or mistake
errors
Potential for check to recover or miss
errors at 1.7, 2.1.1 and 2.1.3
Input slip/lapse or mistake errors in
incomplete check
1 & 2. Patient given inappropriate
medication.
3.
IV/IT error. All of above have potentially
major consequences - however further
potential for recovery at 2.3.1 or 4.4.3
NON-LUER: IT syringes will be distinct from
IV - less chance of picking wrong syringes
thereby minimising input slip/lapse or mistake
errors. However With current NON-LUER
prototypes could be difficult to see when
syringe fully primed due to opaque/translucent
connector on end of syringe
Pht
Labels inaccurate (drug, dose, patient,
route of admin) due to inaccurate sheet.
Any concern whether label inaccurate
should trigger check on prescription
Labelling error triggered earlier by incorrect
sheet
Need to re-print label
Visual distinctiveness of NON-LUER may help
trigger realisation that labelling is incorrect
Ph/T
Label attached to wrong syringe
Out put slip/lapse or mistake. Could be
violation but would need to be malicious
If not subsequnetly revcovered could
result in incorrect administration
Visual distinctiveness of NON-LUER may help
trigger realisation that labelling is incorrect
Ph/T
Ph/T
Ph/T
Pht
Pht
2.5.2 Fill in 8.1 - 8.5 of page 2 of Chemotherapy Worksheet
Pht
Pht
Action
Initiator
Activity
DRUG RELEASE/COLLECTION/STORAGE
Pht signs prescription release section (defines storage
area). Prescription placed in green box, & box sealed.
Potential for 10x or 5x error from 2.1.1
Input - slip/lapse or mistake or Decision recovered however check could also fail
violation (would need to be malicious)
prepetuating error at 2.1.1 - Wrong strenth
vial (Methotrexate: 50mg in 2ml or 5mg in 2
ml. Cytarabine 100mg in 5ml or 500mg in
5ml).
Ph/T
2.5.1 Pharmacist checks IT drugs have been made up
correctly (includes reconciliation of materials and
components, visual inspection of product, label
reconciliation)
HTA No.
3
3.1
Ph/T
Ph/T
Ph/T
NON LUER: will be lock cap - less likely to
come off, less infection risk.
Pht
Action
Taker
Pht
Potential for recovery of errors at 1.7, 2.2.2
& 2.3.1
Potential Error
Potential Error Type
Potential Consequence of Error
Potential Advantages/Disadvantages with
Non-Luer
3.2
Box containing drugs leaves asceptics. Either
(a) collected by administering C/SR
(b)
delivered to designated area and given directly to C/SR
OR placed in IT refrigerator
3.3
Administering C/SR signs collection section on bottom of C or SR
prescription to confirm receipt from either Pht or IT
refridgerator
C or SR
3.4
Drugs stored at site of administration in locked container C or SR
(if administration delayed - drugs destroyed in cytotoxic
incinorator bins. In this case "Destroyed - Not Given" is
written on prescription sheet)
C or SR
HTA No.
4
4.1
4.2
4.3
PREPARATION FOR ADMINISTRATION
Patient arrives - check correct identity against wristband
(parents/self confirm identity) - captures practise in all 3
designated areas
PATIENT ANAESTHETISED
4.2.1 Either Intravenous and/or gaseous general anaesthetic
administered until patient suitably anaesthetised
PATIENT PREPARED
4.3.1 Patient placed on side, with back facing C/SR
Ph/T/C/SR
Action
Initiator
Activity
4.3.2 Patient's clothes adjusted to reveal lumbar region of
spine
4.4
Ph/T/C/SR
Action
Taker
C/SR
C/SR/TS/
Nurse
A
A
TS
TS
CHECKS PERFORMED
4.4.1 Sealed green box (containing syringe and IT prescription ITN
sheet) removed from locked fridge and opened. (NB: In
certain circumstances, sealed green box handed directly
to administrator)
Placed in wrong fridge
Potential Error
Output slip/lapse or mistake
Potential Error Type
Confusion with IV drugs. If not
subsequnetly revcovered could result in
incorrect administration. Should be
recovered at 3.3.
Potential Consequence of Error
1. Wrong patient.
2.
Inappropriate (not IT trained) personnel.
Failure to check patient is violation of
procedure however if patient names simliar
could be slip/lapse or mistake.
Use of inappropriate (not IT trained)
personnel = violation
Drug administered to incorrect patient
TS
Poorly positioned patient
TS
Failure to correctly locate injection site
Mistake (unlikely unless inexperienced
personnel)
Mistake (unlikely unless inexperienced
personnel)
Ineffective needle placement may need
repeating
Ineffective needle placement may need
repeating
Potential Advantages/Disadvantages with
Non-Luer
ITN/C/SR
4.4.2 ITN & administering doctor check drug & prescription
ITN & C or SR ITN & C or
(name, dose, volume, batch no., route of admin, date of
SR
admin & expiry date). Prescription sheet signed by C/SR
& ITN, & batch number noted
1. Inappropriate (not IT trained) personnel. Failure to check patient is violation of
2. Wrong patient, wrong drug, wrong route procedure however if patient names simliar
could be slip/lapse or mistake.
of admin.
Use of inappropriate (not IT trained)
personnel = violation
Drug administered to incorrect patient
4.5
Appropriate spinal needle selected (according to size of
patient)
C or SR
C or SR
Inappropriate needle selection
Input slip/lapse or mistake
Increased chance of post LP headache
4.6
C/SR locates injection site by feeling lumbar region of
spine and prepares area
C or SR
C/SR
Failure to correctly locate injection site
Mistake (unlikely unless inexperienced
personnel)
Ineffective needle placement may need
repeating
5
5.1
ADMINISTRATION
NEEDLE PLACEMENT
In NON-LUER system this is prevented
5.2
5.3
5.1.1 Spinal needle pushed in between lumbar vertebrae
C/SR
C/SR
Pink prototype very chunky/cumbersome
which could cause end of needle to move
5.1.2 Force applied until decreased resistance to the needle
indicates correct placement and removes trochar
C/SR
C/SR
Decreased resistence to the needle not
identified
5.1.3 CSF fluid leaks out through the needle
Several drops CSF collected into collection tube for
monitoring/diagnosis
C/SR
ITN
C/SR
ITN/TS
C or SR
C or SR
C or SR
C or SR
C or SR
C or SR
SYRINGE ATTACHED
5.3.1 If more than one IT drug to be given 3-way tap attached
to needle
5.3.2 Syringe cap removed from syringe
5.3.3 End of syringe joined to end of spinal needle (or 3-way
tap) using Luer slip connection
5.4
Drug given by pushing in plunger of syringe in until
complete dose has entered the spinal canal
C or SR
C or SR
5.5
Spinal needle and syringe (which remain attached to one C or SR
another) gently pulled out
C or SR
5.6
Precription signed by doctor (administered) and nurse
(witnessed). Time of administration noted.
HTA No.
6
6.1
Activity
C or SR & ITN C or SR &
ITN
Action
Initiator
Mistake (unlikely unless inexperienced
personnel)
Ineffective needle placement may need
repeating
Need non-Luer 3-way tap
Full range of compatible syringe and needles
will be required with NON-LUER connections
Incomplete dose administred
Input slip/lapse or mistake
Treatment effectiveness potentially
reduced
Not done
Violation of procedures however could be
caused by slip/lapse or mistake if assumed
done
Process not documented as complete
Action
Taker
Potential Error
Potential Error Type
Potential Consequence of Error
POST PROCEDURE CARE
ITN/C/SR/TS
ITN/C/SR/TS Not wiped
Violation of procedures however could be
caused by slip/lapse or mistake if assumed
done
Infection
6.2
Injection site wiped clean
Sticking plaster attached over injection site
ITN/C/SR/TS
ITN/C/SR/TS Not attached
Violation of procedures however could be
caused by slip/lapse or mistake if assumed
done
Infection
7
7.1
DISPOSAL
Needle and syringe placed in cytotoxic sharps bin
C or SR
C or SR
Not placed in cytotoxic bin
Violation of procedures however could be
caused by slip/lapse or mistake if assumed
done
Dangerous material left uncontrolled
7.2
Other materials deposited in clinical waste bin
C or SR
C or SR
Not done
Violation of procedures however could be
caused by slip/lapse or mistake if assumed
done
Dangerous material left uncontrolled
7.3
Cytotoxic sharps bin removed when full and incinerated
ITN
ITN
7.4
Green IT Box taken back. If drugs not given, disposal
noted on prescription sheet
C or SR
C or SR or
ITN
Not done
Violation of procedures however could be
caused by slip/lapse or mistake if assumed
done
Dangerous material left uncontrolled
8
DOCUMENTATION
Exisitng portotypes need to be considered in
relation to (a) awareness of extent of deadspace (b) visual clarity - opaque/translucent
material
Potential Advantages/Disadvantages with
Non-Luer
8.1
C or SR
C or SR
Not done
Violation of procedures however could be
caused by slip/lapse or mistake if assumed
done
Inadequate patient records
ITN/C/SR/Pht
ITN/C/SR/Pht Not done
Violation of procedures however could be
caused by slip/lapse or mistake if assumed
done
Inadequate patient records
Procedure recorded in patient's notes - date, time,
administering C/SR,
8.2
IT chemo administration audit pro-forma completed and
returned to pharmacy
Key to Abbreviations:
C
Consultant
SR
Specialist Registrar
Pharmacy Staff
Ph
Pht
Pharmacist
Technician
T
ITN
Intrathecal Trained Nurse
Theatre Staff
TS
A
Anaesthetist
All on IT
Reg
Adult Intrathecal Chemotherapy - Potential Error Analysis
Activity
HTA No.
Action
Initiator
Action
Taker
Potential Error
Potential Consequence of Error
Potential Error Type
1
1.1
PRESCRIPTION
Drugs prescribed by C or SR (on correct intrathecal chart)
C or SR
C or SR
1.Incorrect drug chart choice (e.g. cytarabine
instead of methotrexate)
2. Incorrect patient label
3. Platelet count inadequate
4. Drugs prescribed by unauthorised medical
staff (anyone not on register)
1. Input - slip/lapse or mistake
2. Input - slip/lapse or mistake
Decision - slip/lapse or mistake
Decision - violation
1.Potential recovery by C or PHt. At
3. 2.1.1. If not recovered wrong IT drug
made up and given.
2.
4.
Drugs given to wrong patient
3. Bleed in CSF
4. Illegal prescription
1.2
IT Chemo chart authorised by C
C
C
1.Incorrect drug chart choice (e.g. cytarabine 1. Input - slip/lapse or mistake
instead of methotrexate)
2. Input - slip/lapse or mistake
2. Incorrect patient label
Decision - slip/lapse or mistake
3. Platelet count inadequate
1.Potential recovery by C or PHt. At
3. 2.1.1 If not recovered wrong drug
made up and given.
2.
Drugs given to wrong patient
3. Bleed in CSF
1.3
Drug route and administration already printed on IT prescription
chart
1.4
Chart printed onto blue paper - includes drug and route of
administration
C or SR
Ph
1.5
Pht checks prescription
Pht
Pht
1.Incorrect drug chart choice (e.g. cytarabine 1. Input - slip/lapse or mistake
instead of methotrexate)
2. Input - slip/lapse or mistake
2. Incorrect patient label
Decision - slip/lapse or mistake
3. Platelet count inadequate
1.Potential recovery by C or PHt. At
3. 2.1.1 If not recovered wrong drug
made up and given.
2.
Drugs given to wrong patient
3. Bleed in CSF
1.6
Out of hours prescriptions must be must be authorised by C
C
C
Authorised by other than C
Decision - violation
Potential recovery at 1.7 or 2.1.1
1.7
Prescription faxed to aseptics for preparation (original delivered Pht
to asceptics by Pht before drugs can be released)
Pht
Drugs released without original prescription
Output - slip/lapse or mistake
Drugs arrive on ward at wrong time
(but would not be administered
without original prescription)
Activity
HTA No.
2
2.1
Action
Initiator
Action
Taker
Potential Error
Potential Error Type
Potential Consequence of Error
1. Input (misread), Output (incorrectly entered) slip/lapse or mistake (could also be violation but
would need to be malicious)
2. Input
(misread), Output (incorrectly entered) slip/lapse or mistake (could also be violation but
would need to be malicious)
3. Input
(misread), Output (incorrectly entered) slip/lapse or mistake (could also be violation but
would need to be malicious)
1. Patient given inappropriate
medication
2.
Patient given inappropriate medication
3. Intra-venous/intrathecal error
All above have potentially major
consequences - however potential for
recovery at 2.2.3, 2.3.1, 2.3.6, 6.1.5
and 6.1.6
Potential advantages/disadvantages with
Non-luer
Potential advantages/disadvantages with
Non-luer
DRUG PREPARATION
MAKING UP
2.1.1 Create and print worksheet (one per IT injection), generate
labels
Ph
Ph
1. Wrong patient,
2. Wrong drug,
3. Wrong route of admin.
Worksheet can be printed correct, but filled
out inaccurately = mistake in labelling
2.1.2 Put together tray (green for IT, blue for IV) ensuring correct no.
of vials, drug, no. of syringes, filter size
Ph
T
Wrong strenth vial (Methotrexate: 50mg in
Input - slip/lapse or mistake
2ml or 5mg in 2 ml. Cytarabine 100mg in 5ml Decision - violation (but would need to be
or 500mg in 5ml).
malicious)
2.1.3 Cytotoxic drug drawn from vials into syringe
Ph
T
2.1.4 Drug inserted (through 0.22 micron microbiological filter [max 4
at a time]) into individual [10ml or 1ml]) syringes for each
patient. Note: Depocyte not filtered Integrity of filter checked
before release from cabinet.
Ph
T
Drug not filtered/filter not working.
Input - slip/lapse or mistake
Particulate matter in syringe - injected With current NON-LUER prototypes could be
difficult to see when syringe due to
into CSF
opaque/translucent connector on end of
syringe
2.1.5 Syringe cap attached to each syringe (should be provided
separately - not connected together)
Ph
T
1. Syringe cap comes off (as Luer is slip
connection, not lock);
Output - slip/lapse or mistake (insufficently
secured)
1. Need to re-make IT administration; NON LUER: will be lock cap - less likely to
2. Infection
come off, less infection risk.
2.1.6 Empty vials placed in sealable bag ready to leave cabinet
Ph
T
Empty vials not sent out (go straight into
incinerator bin)
or
10x (Methotrexate) or 5x (Cytarabine) NON-LUER: IT syringes will be distinct from
drug error
IV - less chance of picking wrong syringes
thereby minimising input slip/lapse or mistake
errors
2.2
2.3
CHECKING
2.2.1 Vials counted
Pht
Pht
2.2.2 Vials checked (name, strength and volume of drug, batch
number, expiry date, manufacturer and appropriateness for
intrathecal delivery checked)
Pht
Pht
Potential for 10x or 5x error from 2.1.2
recovered however check could also fail
prepetuating error at 2.1.2 - Wrong strenth
vial (Methotrexate: 50mg in 2ml or 5mg in 2
ml. Cytarabine 100mg in 5ml or 500mg in
5ml).
Input - slip/lapse or mistake
Decision - violation (but would need to be
malicious)
2.2.3 Syringes checked against prescriptions to ensure correct drug & Pht
volume being given and no impurities (bung, glass etc.) present
Pht
Potential for check to recover or miss errors
at 2.1.1, 2.1.2 and 2.1.4
Input slip/lapse or mistake errors in incomplete
check
Pht
Labels inaccurate (drug, dose, patient, route Labelling error triggered earlier by incorrect
of admin) due to inaccurate sheet. Any
sheet
concern whether label inaccurate should
trigger check on prescription
Pht
Label attached to wrong syringe
Out put slip/lapse or mistake. Could be violation If not subsequnetly revcovered could
result in incorrect administration
but would need to be malicious
Failure to attach prescription
Out put slip/lapse or mistake.
10x (Methotrexate) or 5x (Cytarabine) NON-LUER: IT syringes will be distinct from
IV - less chance of picking wrong syringes
drug error
thereby minimising input slip/lapse or mistake
errors
1. Patient given inappropriate
medication
2.
Patient given inappropriate medication
3. Intra-venous/intrathecal error
All above have potentially major
consequences - however further
potential for recovery at 2.3.6, 6.1.5
and 6.1.6
NON-LUER: IT syringes will be distinct from
IV - less chance of picking wrong syringes
thereby minimising input slip/lapse or mistake
errors. However With current NON-LUER
prototypes could be difficult to see when
syringe fully primed due to
opaque/translucent connector on end of
syringe
Need to re-print label
Visual distinctiveness of NON-LUER may
help trigger realisation that labelling is
incorrect
LABELLING
2.3.1 Labels (white - same as IV) checked against prescription and
contents of syringe
2.3.2 Label attached to each syringe (along measurement markings)
Pht
2.4
or
2.3.3 Labelled syringes placed in individual bags (clear, or red - to
protect methotrexate from light) and sealed
Pht
2.3.4 Label attached onto sealed bag
Pht
2.3.5 Label attached to worksheet
Pht
2.3.6 Prescription sheet signed by Pht for release. Worksheet signed Pht
for prep and release. Aseptics IT log signed for prep and release
Pht
PROCESSING
2.4.1 Bags placed in green box (one box per patient). Prescription
attached to box using cable tie
Ph
Pht
2.4.2 Box sealed (using cable tie)
Ph
Pht
Should be recovered at 3.1, 3.2, 4.1 or
4.2
Visual distinctiveness of NON-LUER may
help trigger realisation that labelling is
incorrect
Action
Initiator
Activity
HTA No.
Action
Taker
Potential Error
Potential Error Type
Potential Consequence of Error
3
DRUG RELEASE
3.1
Box leaves asceptics, for either
by administering C/SR (rare)
refridgerator (on ward)
(a) collection Pht
(b) placement in IT
Pht
Placed in wrong fridge
Output slip/lapse or mistake
Confusion with IV drugs. If not
subsequnetly revcovered could result
in incorrect administration. Should be
recovered at 4.2
3.2
Pht signs IT prescription to confirm release to either (a) C/SR Pht
that will administer drugs - Pht identifies to whom drugs are
released
(b) IT refridgerator - Pht signs
prescription to state drugs have been placed in appropriate
refridgerator. Note: Pht must be on IT chemo register
Pht
Drugs placed in incorrect fridge (unlikely)
Confusion with IV drugs
Confusion with IV drugs. If not
subsequnetly revcovered could result
in incorrect administration. Should be
recovered at 4.2
4
DRUG COLLECTION
4.1
Administering C/SR collects drugs
C or SR
C or SR
4.2
Administering C/SR signs prescription to confirm receipt from
either Pht or IT refridgerator
C or SR
C or SR
5
DRUG TRANSPORTATION
5.1
Drugs transported to site of administration by administering
C/SR
Drugs stored at site of administration in sealed container (if
administration delayed - returned to pharmacy IT fridge)
C or SR
C or SR
C or SR
C or SR
5.2
Activity
HTA No.
6
PREPARATION FOR ADMINISTRATION
6.1
CHECKS PERFORMED
6.2
Action
Initiator
Action
Taker
Potential Error
Potential Error Type
Potential Consequence of Error
6.1.1 Check enviroment appropriate (i.e. designated room - no other
chemo drugs present) for IT administration. Deviation from
policy muct be authorised by C
ITN & C/S ITN & C/SRIV drugs could be present - potential for
wrong route error
Initially violation (i.e. IV drugs present contrary to Death or severe neurological
procedures) Subsequently output slip/lapse or
impairment
mistake
6.1.2 Check haemostasis adequate
C or SR
C or SR
Haemostasis inadequate
Inadequately checked - input slip/lapse or
mistake
CSF bleed
6.1.3 Obtain consent for procedure
C or SR
C or SR
Performed without consent
Inadequately checked - input slip/lapse or
mistake
Legal consequences
6.1.4 Sealed bag (containing syringe and IT prescription sheet)
removed from sealed container and opened
ITN
ITN
6.1.5 ITN and administering doctor check patient identity and sign
against prescription chart
ITN & C/S ITN & C or 1. Wrong patient. 2. Inappropriate (not IT
SR
trained) personnel.
6.1.6 IT trained nurse and administering doctor check drug &
prescription (name, colour, dose, volume, batch no., date of
administration & expiry date)
ITN & C/S ITN & C or 1. Inappropriate (not IT trained) personnel. 2. Failure to check patient is violation of procedure Incorrect drug asdministered to
SR
Wrong patient, wrong drug, wrong route of
however if patient names simliar could be
patient
admin.
slip/lapse or mistake.
Use of
inappropriate (not IT trained) personnel is
violation of procedure
Appropriate spinal needle selected (22G most practical -with
pencil point tip)
C or SR
Inapprop needle selection.
Potential advantages/disadvantages with
Non-luer
Potential advantages/disadvantages with
Non-luer
Visual distinctiveness of NON-LUER may
help distinguish between potential to confuse
IT and IV
Failure to check patient is violation of procedure Drug administered to incorrect patient
however if patient names simliar could be
slip/lapse or mistake.
Use of
inappropriate (not IT trained) personnel is
violation of procedure
Input slip/lapse or mistake
Increased chance of post LP
headache
Wrong patienet should be avoided by cockpit
style cross-checking
In NON-LUER system this is prevented
6.3
PATIENT PREPARED
6.3.1 Patient placed on side, with back facing C/SR
ITN & C/S ITN & C/SRPoorly positioned patient
Mistake (unlikely unless inexperienced
personnel)
Ineffective needle placement may
need repeating
6.3.2 Patient's clothes adjusted to reveal lumber region of spine,
considering patient dignity and comfort
ITN & C/S ITN & C/SRFailure to correctly locate injection site
Mistake (unlikely unless inexperienced
personnel)
May need repeating
6.3.3 C/SR/Doctor under supervision locates injection site by feeling
lumbar region of spine and prepares area (with swabs and
chlorhexidine solution) [Asceptic technique]
C or SR
C/SR/
Trainee
Non aseptic technique
Violation of procedure - could be slip/lapse or
mistake if assumed done
Infection
6.4.1 Local anaesthetic injected into LP site
C/SR/
Trainee
C/SR/
Trainee
Anaesthetic instilled in epidural space
Mistake (unlikely unless inexperienced
personnel)
Epidural anaesthetic
6.4.2 Ensure appropriate local anaesthetic given
C/SR/
Trainee
C/SR/
Trainee
Inappropriate anaesthetic given
Mistake (unlikely unless inexperienced
personnel)
Patient feels pain
6.4
PATIENT ANAESTHETISED
Activity
HTA No.
7
7.1
Action
Initiator
Action
Taker
Potential Error
Potential Error Type
Potential Consequence of Error
Potential advantages/disadvantages with
Non-luer
ADMINISTRATION
NEEDLE PLACEMENT
7.1.1 If using pencil point - sheath needle passed through skin.
C/SR/
Trainee
C/SR/
Trainee
7.1.2 Spinal needle pushed in between lumbar vertebrae
C/SR/
Trainee
C/SR/
Trainee
1. Multiple attempts at needle placement.
2. Incorrect placement (i.e. too high)
Mistake (unlikely unless inexperienced
personnel)
Increased risk of CSF leak (and
headaches) and increased pain.
Damage to spinal cord.
7.1.3 Force applied until decreased resistence to the needle indicates C/SR/
Trainee
correct placement
C/SR/
Trainee
Decreased resistence to the needle not
identified
Mistake (unlikely unless inexperienced
personnel)
Multiple attempts at needle
placement.
7.1.4 Trochar removed from spinal needle
C/SR/
Trainee
C/SR/
Trainee
7.1.5 CSF fluid leaks out through the needle
C/SR/
Trainee
C/SR/
Trainee
ITN
ITN
7.3.1 If more than one IT drug to be given, 3 way tap attached to
needle
C or SR
C or SR
7.3.2 Syringe cap removed from syringe
C or SR
C or SR
7.3.3 End of syringe joined to end of needle using Luer slip
connection
C or SR
C or SR
Introduction of air (more opportunity for this
when using 3 way tap)
Output slip/lapse or mistake
Air in CSF
Full range of compatible syringe and needles
will be required for NON-LUER connections
7.4
Drug/flush given by pushing in plunger of syringe until complete C or SR
dose has entered the spinal canal
C or SR
Incomplete dose administred
Input slip/lapse or mistake
Treatment effectiveness potentially
reduced
Exisitng portotypes need to be considered in
relation to (a) awareness of extent of deadspace (b) visual clarity - opaque/translucent
material
7.5
Needle and syringe (which remain attached to one another)
gently pulled out
C or SR
7.2
7.3
Several drops CSF collected into collection tube(s) for
monitoring/diagnosis (pressure could be measured with
manometer)
SYRINGE ATTACHED
C or SR
NON-LUER: will need compatible 3 way tap
Activity
HTA No.
Action
Initiator
Action
Taker
Potential Error
Potential Error Type
Potential Consequence of Error
8
POST PROCEDURE CARE
8.1
Injection site wiped clean
ITN
ITN
Not wiped
Violation of procedures however could be
Infection
caused by slip/lapse or mistake if assumed done
8.2
Dressing attached over injection site
ITN
ITN
Not attached
Violation of procedures however could be
Infection
caused by slip/lapse or mistake if assumed done
8.3
CSF sample sent to lab
C or SR
C or SR
Mislabeled sample, or sent to incorrect lab
Output slip/lapse or mistake
Impacts on number of subsequent
IT's, or delay in treatment
8.4
Patient lies flat for 1 hour post procedure
ITN
ITN
Doesn't lie flat for 1 hr
Output slip/lapse or mistake if patient not
advised or supervised
Headache, reduced efficacy of IT
9
DISPOSAL
9.1
Needle and syringe placed in cytotoxic sharps bin
C or SR
C or SR
Not placed in cytotoxic bin
Violation of procedures however could be
Dangerous material left uncontroled
caused by slip/lapse or mistake if assumed done
9.2
Other materials deposited in clinical waste bin
C or SR
C or SR
Not done
Dangerous material left uncontroled
Violation of procedures however could be
caused by slip/lapse or mistake if assumed done
9.3
Box taken back (empty). Unused IT drugs destroyed in clinical
area ("IT not given, destroyed in clinical area" written on
prescription, with date & signed)
C or SR
& ITN
C or SR or Not done
ITN, Pht
(destroys)
Dangerous material left uncontroled
Violation of procedures however could be
caused by slip/lapse or mistake if assumed done
10
10.1
DOCUMENTATION
Prescription sheet signed by administering C/SR and ITN
C or SR
& ITN
C or SR & Not done
ITN
Violation of procedures however could be
Process not documented as complete
caused by slip/lapse or mistake if assumed done
10.2
Procedure recorded in patient's notes
C or SR
C or SR
Violation of procedures however could be
Inadequate patient records
caused by slip/lapse or mistake if assumed done
Key to Abbreviations: (all IT trained)
C
Consultant
SR
Specialist Registrar
Ph
Pharmacy Staff
Pht
Pharmacist
Technician
T
Intrathecal Trained Nurse
ITN
Theatre Staff
TS
Anaesthetist
A
Not done
Potential advantages/disadvantages with
Non-luer
Appendix C: Hierarchical Task Analysis
(i)
Hierarchical Task Analysis of Spinal Anaesthesia
HTA
Activity
No.
1
PREPARE EQUIPMENT
1.1 Prepare equipment to be used: Spinal needle (24/25G with pencil point), Introducer if
appropriate (e.g. 19G), syringe for IT anaesthetic, syringe for local anaesthetic,
Hypodermic needles for drawing up IT & local anaesthetic, and infiltrating local into
skin, Antiseptic (e.g. chlorhexidine), Sterile gauze swabs, Dressing/plaster to cover
puncture site, local anaesthetic (e.g. 1% lignicaine) IT anaesthetic (in single-use
ampoule, e.g. 0.5% heavy bupivicaine)
2
CHECKS
2.1 Patient arrives
2.2 Check correct patient
2.3 Check sufficient equipment for procedure
Establish IV access (draw up local anaes for skin infiltration and potentially est IV
infusion)
Locate Check label on local anaesthetic vial and open anesth agent (skin)
Draw up ephedrine (rescue drug for problem with neuroxial blockade) +/- atropine, +/glycopyrronium
Draw up gen anaes agent (best practice but not standard). Potentially other agents (for
other patients) present
Locate Check label on local anaesthetic vial and open anesth agent
Draw up IT anaesthetic into syringe using hypodermic needle
Draw up local anaesthetic into syringe using hypodermic needle
4
PATIENT PREPARATION
4.1 Lying on side/sitting up (sitting up more common in anaesthesia), head down and
knees brought up to chin
4.4 Locate suitable space for injection (below L2)
4.5 Mark puncture site (using finger nail or felt pen)
4.2 Clean back with swabs & antiseptic
4.3 Blue paper drape (with hole for puncture site) draped over patient
5
LOCAL ANAESTHETIC
5.1 Inject small amount of local anaesthetic under skin at puncture site (using 2ml syringe
and hypodermic needle)
5.2 Inject deeper into patient using longer needle (not always done in case of spinal)
6
SPINAL NEEDLE PLACEMENT
6.1 Insert introducer needle (if using)
6.2 Insert spinal needle (through introducer, if applicable)
6.4 Feel for loss of resistance as needle enters dura
6.5 Remove stylet
6.6 CSF flows from needle
27
6.7 If no CSF appears attach syringe and aspirate. If no CSF appears, replace stylet,
advance needle a little further and remove stylet once more (repeat until CSF flows
from needle)
7
IT ANAESTHETIC ADMINISTRATION
Identify syringe containing IT anaesthetic
7.1 Attach syringe containing IT anaesthetic to spinal needle (taking care not to alter the
position of the spinal needle)
7.2 Aspirate gently to check the needle tip is still intrathecal
7.3 Inject IT anaesthetic slowly and carefully
Aspirate to ensure injection has entered CSF
7.4 Withdraw spinal needle, introducer and syringe together
8
POST PROCEDURE CARE
8.1 Wipe puncture site clean
8.2 Apply dressing/plaster to puncture site
9
TEST BLOCK
9.1 Ask patient to lift legs, spray cold spray along patient’s body, sensation to touch tested
10
DISPOSAL
10.1 Needles and empty vials disposed of in sharps bin
10.2 All other waste disposed of in clinical waste bin
11
RECORD PROCEDURE
11.1 Administered drugs written on the anaesthetic chart
11.2 For controlled drugs (e.g. fentanyl) clinician and nurse/ODP sign register to confirm
administration
(ii)
Hierarchical Task Analysis of Non-Therapeutic Lumbar Puncture
HTA No.
1
Activity
PREPARE EQUIPMENT
1.1 Prepare equipment to be used: Spinal needle (24/25G with pencil point),
Introducer if appropriate (e.g. 19G), 2ml/5ml syringe for local anaesthetic,
Hypodermic needles for drawing up local anaesthetic, and infiltration into skin,
Antiseptic (e.g. chlorhexidine), Sterile gauze swabs, Dressing/plaster, Collecting
pots for CSF samples
2
CHECKS
2.1 Patient arrives
2.2 Check correct patient
2.3 Check sufficient equipment for procedure
3
DRUG PREPARATION
3.3 Check label on local anaesthetic vial (correct drug, expiry, etc)
3.4 Draw up local anaesthetic into 2ml/5ml syringe using hypodermic needle
4
PATIENT PREPARATION
4.1 Lying on side, head down and knees brought up to chin
4.2 Clean back with swabs & antiseptic
28
4.3 Blue paper drape (with hole for puncture site) draped over patient
4.4 Locate suitable space for injection (below L2)
4.5 Mark puncture site (using finger nail or felt pen)
5
LOCAL ANAESTHETIC
5.1 Inject small amount of local anaesthetic under skin at puncture site (using 2ml
syringe and hypodermic needle)
5.2 Inject local deeper into patient using longer needle
6
SPINAL NEEDLE PLACEMENT
6.1 Insert introducer needle (if using)
6.2 Insert spinal needle (through introducer, if applicable)
6.3 Feel for loss of resistance as needle enters epidural space
6.4 Feel for 2nd loss of resistance as needle enters dura
6.5 Remove stylet
6.6 CSF flows from needle
6.7 If no CSF appears, replace stylet, advance needle a little further and remove
stylet once more (repeat until CSF flows from needle)
7
SAMPLE CSF
7.1 Allow desired amount of CSF to drip into collecting pot
7.2 Repeat until desired number of samples have been taken
7.3 Carefully remove spinal needle (and introducer, if using)
8
POST PROCEDURE CARE
8.1 Wipe puncture site clean
8.2 Apply dressing/plaster to puncture site
10
DISPOSAL
10.1 Needles and empty vials disposed of in sharps bin
10.2 All other waste disposed of in clinical waste bin
11
RECORD PROCEDURE
(iii)
Hierarchical Task Analysis of Measurement of CSF Pressure
HTA No.
1
Activity
PREPARE EQUIPMENT
1.1 Prepare equipment to be used: Spinal needle (24/25G with pencil point),
Introducer if appropriate (e.g. 19G), 2ml/5ml syringe for local anaesthetic,
Hypodermic needles for drawing up local anaesthetic, and infiltration into skin,
Antiseptic (e.g. chlorhexidine), Sterile gauze swabs, Dressing/plaster, Collecting
pots for CSF samples, Manometer
2
CHECKS
2.1 Patient arrives
2.2 Check correct patient
2.3 Check sufficient equipment for procedure
3
DRUG PREPARATION
3.3 Check label on local anaesthetic vial (correct drug, expiry, etc)
3.4 Draw up local anaesthetic into 2ml/5ml syringe using hypodermic needle
29
4
PATIENT PREPARATION
4.1 Lying on side, head down and knees brought up to chin
4.2 Clean back with swabs & antiseptic
4.3 Blue paper drape (with hole for puncture site) draped over patient
4.4 Locate suitable space for injection (below L2)
4.5 Mark puncture site (using finger nail or felt pen)
5
LOCAL ANAESTHETIC
5.1 Inject small amount of local anaesthetic under skin at puncture site (using 2ml
syringe and hypodermic needle)
5.2 Inject local deeper into patient using longer needle
6
SPINAL NEEDLE PLACEMENT
6.1 Insert introducer needle (if using)
6.2 Insert spinal needle (through introducer, if applicable)
6.3 Feel for loss of resistance as needle enters epidural space
6.4 Feel for 2nd loss of resistance as needle enters dura
6.5 Remove stylet
6.6 CSF flows from needle
6.7 If no CSF appears, replace stylet, advance needle a little further and remove
stylet once more (repeat until CSF flows from needle)
7
MEASURE CSF PRESSURE
7.1 Attach manometer to spinal needle
7.2 When CSF has stopped rising, ask patient to cough
7.3 Take reading of CSF pressure
8
DRAIN CSF (IF NECESSARY)
8.1 Open tap on manometer to drain CSF
8.2 When desired amount of CSF has drained, close tap to stop CSF flow
8.3 Measure CSF pressure again (repeat steps 7.2 & 7.3)
8.4 If pressure is acceptable, continue to 9. If not, repeat steps 8.1 - 8.3
9
TAKE CSF SAMPLES
9.1 Open tap on manometer
9.2 Allow desired amount of CSF to drip into collecting pot
9.3 Repeat until desired number of samples have been taken
9.4 Close tap on manometer
9.5 Carefully remove spinal needle & manometer (and introducer, if using)
10
POST PROCEDURE CARE
10.1 Wipe puncture site clean
10.2 Apply dressing/plaster to puncture site
11
DISPOSAL
11.1 Needles and empty vials disposed of in sharps bin
11.2 All other waste disposed of in clinical waste bin
12
RECORD PROCEDURE
30
Appendix D: NHS Logistics Supply Chain Analysis
Supply chain review
Implementing a new range of non-Luer consumables to the English NHS
Author: Jon Edwards
Title: Service Development Manager
Department: Supply Chain Services
31
Implementing a non Luer solution for spinal procedures
Summary
The Luer lock consumables are currently supplied by a mature pan global supply chain and Acute
NHS trusts provide the majority of the UK demand for these products. To facilitate internal
processes many procedure packs have been developed to reduce clinical preparation time. By
developing a new non Luer product range risk is introduced by the reduced supplier base and
potentially a restrictive product range for procedure packs.
The implementation is complex as the consumables are used widely across trust departments.
This increases the importance for clear communication of changes to end users. The risk of
implementation problems is high but can be mitigated successfully with advance production
planning, short term excess safety stock and a phased customer stock build and service
implementation.
The customers for Luer lock consumables
There are currently 258 NHS organisations that use Luer consumables through national contracts.
Acute trusts account for 95% of the product demand. The new product range is not expected to
impact on any new customer groups (see appendix 1.1).
The supplier base
There are currently 10 suppliers who supply the NHS with the Luer range on national contracts
(see appendix 1.2), between them they provide 218 product lines.
The existing Luer lock consumable market has a pan global manufacturing base with suppliers
adding safety stock in the supply chain through the use of a UK distribution point. The only
suppliers not to use a UK distribution point are based in Belgium which is within sufficient proximity
to provide a next day service in event of supply interruption or increased demand.
The proposal to source two existing suppliers for the new products, both of which have a UK
distribution point, would introduce no inherent supply chain risks but the reduction in supplier
numbers may limit the capacity for short term production increases.
Number of products
Number of suppliers
Existing Luer supply chain
218
10
Proposed non Luer supply chain
20 (@10 products and two brands)
2
The trial sites
The trial sites show that the Luer range of products is used widely across the trusts and not
necessarily confined to spinal departments. In Leeds for example there are five areas that
specialise in spinal procedures but 87 different ordering points across the trust using the
consumables (see appendix 1.3).
Customer conversion
Because there is an existing Luer product range then we have a natural contingency and the UK
distributor (NHS Logistics) can increase safety stock levels for the transition period.
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Because customers will need to remove all existing stocks of Luer locking devices in spinal areas it
is recommended that they transfer redundant stock internally through the materials management
teams.
The analysis at Leeds and Sheffield has shown that the existing Luer range is used by many areas
of each site (Leeds have 87 ordering points for Luer consumables) so implementation may be
complicated as multiple store rooms would be affected.
Implementation can only take place when sufficient stock is available in the supply chain to support
an initial stock build and then uninterrupted product supply. Customer groups need to be identified
and prioritised so they can schedule product training, remove redundant stock and communicate to
all end users prior to the new product range being available.
Because the new product range would be used by all Acute trusts initial safety stocks will need to
be built and stocks along the supply chain primed to support abnormally high demand for the
implementation period. It is important to note that once implementation is complete and demand
patterns are established that safety stocks can be reduced.
NHS Logistics systems would support the customer implementation by making the new catalogue
range only available to identified customer groups during the phased implementation and
monitoring customer service levels and supplier performance.
To ensure that the customer implementation is successful and to ensure that the products are to
specification and fully tested the supply chain needs to be developed to deliver the new product
range.
Supply chain implementation steps
New product range developed with end users who test and signoff the product is fit for
purpose
New manufacturing plant developed, implemented and tested.
Capacity of new technology needs to be tested
Initial stocks manufactured
Finished products signed off by end user and quality assurance procedures agreed
Avoids any product recalls from unsuitable product
Contingency/safety stocks developed
Enough safety to cover manufacturing down time from process failure
Supply chain commencement i.e. first shipment
Global manufacturing adds lead time
UK safety stocks at Distributor (NHS Logistics)
Enough to cover one failed shipment (Air freight contingency as product not weight prohibitive)
First customer issues as part of phased project plan and customer stock building
Product training to be delivered prior to first delivery
Phased customer implementation
High safety stock levels maintained
Demand patterns established and stocks forecast with Distributor and supplier
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Demand patterns to look at replenishment orders and not stock priming
Supply chain review to ensure process efficiency and reliability
To ensure that the non Luer consumables are available to end users
Contingency stocks of Luer codes during implementation reduced to new demand levels
Risks
No development of procedure packs (77 of 218 of existing range in procedure packs) - this
would require process variation at end user to source other elements of packs from the
distributor and could increase the need to prepare packs for procedures on site.
With just two suppliers there is increased risk of suppliers leaving the market or long term
production failure. Both suppliers need to have plans to increase capacity short term and
long term.
If supplier brands are not inter-connectable then the risk of a long term supply chain failure
would require other suppliers to deliver training and increase capacity at short notice. This
could lead to a reliance on individual product codes and so manufacturing schedules and
capacity would need to be reviewed and increased safety stocks developed at both
manufacturer and distributor.
With a global supply chain a non UK customer could increase demand on the manufacturer
that could impact on the capacity to supply the UK market. Volume guarantees need to
given by the suppliers for the NHS market.
Implementation is not just confined spinal areas as these products are used widely in Acute
trusts. Any product training or introduction needs to coordinated across trust usage points.
Jon Edwards
Service Development Manager
NHS Logistics
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Appendix
1.1 Customer breakdown of existing Luer range
% of
NHS establishment type
Number of
national
locations
volume
Non-Teaching Acute Trust
62.11%
33.10%
1.82%
1.61%
1.14%
0.22%
145
Teaching Acute Trust
42
Community Trust
4
Combined Trust
1
NHS Service Provider
14
Primary Care Trust
52
Source: NHS Logistics transactions April 2005 to April 2006
1.2 Supplier product range breakdown
Syringe
Supplier
Catheter
Epidural
Manometer
Luer
Procedure
device loss of
filters
spinal set
Needles
packs
resistance
B Braun
9
Becton Dickinson
12
Blue Box Medical
5
Pajunk UK
3
Rocket Medical
1
Sarstedt
Smiths Medical
4
6
6
2
Tyco Healthcare UK
19
69
1
4
1
8
Unomedical
47
Vygon UK
18
Source: NHS Logistics April 2006 Catalogue
1.3
Ordering points at Leeds and Sheffield using Luer lock consumables
Trust site
Ordering points
St James
51
LGI
36
Sheffield Childrens
9
Source: NHS Logistics transactions April 2005 to April 2006
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1.4 Supply route map for Luer lock consumables
Existing supply chain volumes for Luer product range
Distribution point
Product manufacture
UK
Europe
5.2%
60.4%
UK
Europe
72.5%
27.5%
NHS Logistics
NHS end user
distribution network to
Materials management
consolidate
Rest of the world
34.4%
Rest of world
0.0%
Source data (Value) : NHS Logistics consumable supply chain 2005/6
Source data (Supply chain) : NHS Logistics Supply Chain Services
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