Dispatcher recognition of cardiac arrest GRADE grid
Criteria
Judgements
Benefits & harms of the options
Problem
○ No
Is there a problem
priority?
What is the overall
certainty of this
evidence?
○ Probably no
○ Uncertain
● Probably yes
○ Yes
○ Varies
○ No included studies
● Very low
○ Low
○ Moderate
○ High
Research evidence
Additional considerations
Failure to recognise cardiac arrest during the initial
emergency call results in longer dispatch times and lower
survival rates. Kuisma et al (2005, 89) reported that when
dispatch times were under 60sec survival to discharge was
39.4%, whereas when dispatch time exceeded 60sec
survival was reduced to 32.2%. Berdowski et al (2009,
2096) identified that when cardiac arrest was identified by
dispatchers survival at 3 months was 14%, but if cardiac
arrest was not recognised survival at 3 months was 5%.
Gold et al (2009) showed that survival declines on average
3% per minute that EMS is delayed following collapse. If
response times are below 4 minutes survival is not
adversely impacted; however if response times exceed 5
min survival declines at 5.2% per minute.
Relative importance or values of the outcome of
interest
Outcome
Relative
importance
Dispatcher recognition of
cardiac arrest
CRITICAL
Certainty of
the evidence
(GRADE)
⨁◯◯◯
VERY LOW
○
Important
uncertainty or
variability
Is there important
uncertainty about
how much people
value the main
outcomes?
○ Possibly important
uncertainty or
variability
There is limited evidence to suggest that many patients
believe that should they suffer a cardiac arrest that they
Most patients would want early identification of
will survive with favourable neurologic outcome (Straney et cardiac arrest with rapid EMNS response.
Probably no
important uncertainty of al 2014).
variability
○
○
No important
uncertainty of variability
● No known
Criteria
Judgements
Research evidence
Additional considerations
undesirable
○ No
Are the desirable
anticipated effects
large?
○ Probably no
○ Uncertain
● Probably yes
○ Yes
○ Varies
Implementation of new dispatch protocols to identify
cardiac arrest results in improved recognition rates and
increased provision of T-CPR. Heward (2004, 114)
recognition increased from 15% before to 50% after.
Ropollo (2009, 769) missed cardiac arrest cases reduced
from 28% before to 18.8% after. Bohm (2009, 1025)
provision of T-CPR increased from 47% before to 68%
after.
The greatest improvements will be seen where no
protocols to identify cardiac arrest exist. If protocols
exist incremental improvements will be seen with the
introduction of training to recognised agonal
breathing, and the implementation of quality
assurance programs to improve compliance with
dispatch protocols.
Berdowski (2009, 2096) identified that a 100% sensitive
protocol would result in 76% false positive rate.
Increasing the number of cases identified as
suspected cardiac arrest may identify a need for
increased resourcing. Berdowski (2009, 2096)
○ No
Are the undesirable
anticipated effects
small?
○ Probably no
○ Uncertain
● Probably yes
○ Yes
○ Varies
Criteria
Judgements
Research evidence
Additional considerations
○ No
Are the desirable
effects large
relative to
undesirable
effects?
○ Probably no
○ Uncertain
● Probably yes
○ Yes
○ Varies
○ No
Resource use
Are the resources
required small?
○ Probably no
○ Uncertain
● Probably yes
○ Yes
○ Varies
Patients are likely to favour rapid recognition and
response by EMS. Clinicians are aware that time to
intervention is critical to positive outcome.
This needs to be balanced against the resource
requirements and the risk of increased sensitivity
increasing the number of false positive cases.
May require alteration of dispatch software, training
of call centre personnel and ongoing quality
control/monitoring to ensure adherence to call script
questions.
There may be resource issues to consider in those
systems that favour very high sensitivity within
dispatch algorithms.
○ No
Is the incremental
cost small relative
to the net benefits?
○ Probably no
○ Uncertain
● Probably yes
○ Yes
○ Varies
Incremental cost is likely to be small in comparison
to system maintenance costs.
Criteria
Judgements
Research evidence
Additional considerations
Equity
○ Increased
What would be the
impact on health
inequities?
● Probably increased
○ Uncertain
○ Probably reduced
○ Reduced
○ Varies
Acceptability
○ No
Is the option
acceptable to key
stakeholders?
○ Probably no
○ Uncertain
● Probably yes
○ Yes
○ Varies
Dispatch protocols are likely to result in improved
response to all cardiac arrest patients.
Patients, clinicians and commissioners of services are
likely to favour increasing survival from OHCA with
favourable neurologic outcomes. Central to these
improvements are rapid identification and treatment.
Improved outcomes from cardiac arrest is dependent
upon optimising both sensitivity and specificity of
dispatch protocols.
Increasing sensitivity alone will increase response
requirements, increase costs, waste resources and
potentially increase risk. Increasing specificity alone
will reduce response requirement and reduce costs
but at the expense of increasing the number of
patients where cardiac arrest is not recognised.
Criteria
Judgements
Research evidence
Additional considerations
Feasibility
○ No
○ Probably no
○ Uncertain
● Probably yes
○ Yes
○ Varies
Is the option
feasible to
implement?
Most EMS systems have established dispatch
centers. Improving recognition requires optimising
the dispatch process.
Recommendation
Balance of
consequences
Type of
recommendation
Undesirable consequences
clearly outweigh desirable
consequences in most
settings
Undesirable consequences
probably outweigh desirable
consequences in most
settings
The balance between desirable
and undesirable consequences
is closely balanced or
uncertain
Desirable consequences
probably outweigh
undesirable consequences in
most settings
Desirable consequences
clearly outweigh undesirable
consequences in most
settings
○
○
○
○
●
We recommend against offering this
option
We suggest not offering this
option
We suggest offering this
option
We recommend offering this option
○
○
○
●
We recommend EMS call takers determine if a patient is unconsciousness with abnormal breathing. If the victim is unresponsive with abnormal
breathing it is reasonable to assume that the patient is in cardiac arrest at the time of the call.
Recommendation
We recommend dispatchers are educated to identify unconsciousness with abnormal breathing. This education should include recognition and
significance of agonal breathing across a range of clinical presentations.
STRONG recommendation. VERY LOW quality evidence
Two observational studies (Kuisma 2005, 89; Berdowski 2009, 2096) indicate that when cardiac arrest is not recognised, dispatch intervals are longer
and survival to discharge is reduced.
Seven observational studies (Eisenberg 1985, 47; Cairns 2008, 349; Deakin 2010, 853; Flynn 2006, 72; Garza 2003, 955; Ma 2007, 236 and
Vaillancourt 2007, 877) report that sensitivity of dispatch protocols to recognise cardiac arrest ranges from 38% to 96.9%, two of these same studies
indicate that specificity exceeds 99% (Deakin 2010, 853 & Flynn 2006, 72). Positive predictive values range from 45.2% to 97.9% (Cairns 2008, 349;
Deakin 2010, 853; Flynn 2006, 72; and Ma 2007, 236), while the negative predictive value approaches 100% (Deakin 2010, 853; Flynn 2006, 72). A
case control study (Berdowski 2009, 2096) reported that 29% of cardiac arrest calls were not identified during the initial call, and furthermore that
24% of calls categorised as cardiac arrest were in fact not cardiac arrest cases. A cluster randomised controlled trial determined that dispatchers ‘gut
feeling’ did not compare well with AMPDS triage (Weiser 2013, 883).
Scripted dispatch protocols to identify patients who are unconscious with abnormal breathing help to increase cardiac arrest recognition. In one
observational study recognition increased from 15 to 50% (Heward 2004, 115), while in another the provision of dispatcher-prompted CPR rose from
45% to 56% (Eisenberg 1985, 47). More recently, a before-after study reported increased rates of telephone CPR (9.9% to 22.5%) after introduction
of a rigid new protocol (Stipulante 2014, 177). Modifying existing seizure protocols to identify abnormal breathing may also be beneficial; in one study
a new question added to the seizure protocol resulted in an increase in ‘high acuity’ calls from 53% to 77% and increased provision of telephone CPR
(Clawson 2008, 257).
Justification
Recognition of unconsciousness with abnormal breathing is central to dispatcher recognition of cardiac arrest. Many terms may be used to describe
abnormal breathing: difficulty breathing, poorly breathing, gasping breathing, wheezing , breathing, impaired breathing (Bång 2003, 25), occasional
breathing, barely/hardly breathing, heavy breathing, laboured or noisy breathing, sighing, strange breathing (Berdowski 2009, 2096). Agonal breathing
has been reported in approximately 30% of cases (Bohm 2007, 256) which can make obtaining an accurate description of the patients breathing pattern
challenging for call takers. One study identified that agonal breathing was present in 50% of non-identified cardiac arrest calls (Vaillancourt 2007, 877),
while another (Clark 1994, 1022) noted that patients were reported to be conscious and breathing in 27/117 cardiac arrest cases. Other terms that
may help identify possible cardiac arrest cases include “dead”, “is dead”, “cold and stiff”, “blue”, “grey” or “pale”. The aforementioned descriptions may
however be limited owing to cultural influences and language translation limitations (Bång 1999, 175).
Educating call takers to recognise patients who are unconscious with abnormal breathing assists call takers to recognise those patients who may be in
cardiac arrest. A before-after study demonstrated an increase in the provision of telephone CPR from 47% to 68% (Bohm 2009, 1025). Two further
observational studies indicate that educating call takers to recognise unconsciousness and abnormal breathing reduce the incidence where telephone
CPR was not provided by more than 32% (Ropollo 2009, 769; Tanaka 2012, 1235).
Failure to recognise cardiac arrest may be associated with failure to follow protocol and ask questions about consciousness and breathing (Castren
2001, 265; Hallstrom 2003, 123; Dami 2010, 848). One study reported an 83% identification rate overall (80% when abnormal breathing, 89% when
breathing was absent), however when breathing was not described to the dispatcher this was reduced to 69% (Nurmi 2006, 463). Strict adherence to
dispatch protocol would have resulted in a 74% false positive rate in one study (Berdowski 2009, 2096).
Subgroup
considerations
Implementation
considerations
Training call takers/dispatchers to recognise and understand the significance of agonal breathing.
Monitoring and
evaluation
Audit of protocol compliance and monitoring of appropriate dispatch coding should be encouraged.
High quality data from randomized controlled trials are currently lacking. Further studies are required to determine:
Research
possibilities





Which key words used by callers are associated with cardiac arrest?
Impact of adherence to/failure to follow dispatch protocols
Most appropriate educational content to ensure dispatchers are able to recognise the significance of abnormal and agonal breathing
Most appropriate refresher training interval for dispatchers
Is there a difference in recognition rates between dispatchers with a clinical background vs those without a clinical background?