Pediatric Sedation Newsletter – Jan – Feb 2002
Departments of Anesthesiology and Pediatrics, Dartmouth Hitchcock Medical Center,
Lebanon, NH
Editors: Joseph Cravero MD (joseph.cravero@hitchcock.org),
George Blike MD george.blike@hitchcock.org
Website = http://an.hitchcock.org/PediSedation/
Circulation 3005
We are a few days late with this newsletter primarily because we have tried to provide a
new level of technical sophistication in the critical incident report. As you read through
the report you will be asked to click on a couple of URL’s in order to listen to a sound
clip of a pulse oximeter or view a movie that exemplifies the case that is discussed.
Unfortunately you need to have a very recent version of the application “Real Player” in
order to play the movie. If you have Real Player version 7 or lower, (or none) you will
need to download a new version of Real Player. You can download a free version of Real
Player by going to the Real Player website. This can be confusing and tedious. You
should not have to pay for anything or leave a credit card number. http://www.real.com
is the home page. You have to spot the blue text line labeled “Free RealOne Player”. Do
not use the big orange “Free” or “Download Now” buttons as these intended for a 30 day
trial version. After this follow the directions which may require you to register your
email address. If you can successfully do this the application will be of use to you in the
future.
On the other hand you can just read the text and look at the pictures. In any case, we
would love to know if any of you can view the video clip.
Correspondence:
We continue to receive a lot of great mail and we thank all who have sent in questions
and comments.
Radiology Problems:
A reader recently sent us an email that brings up a question we have debated in our own
institution. Without quoting the letter directly, the reader brought up the question of what
to do with a child who needs a sedated CT scan with oral contrast. Many of us are faced
(on an all too frequent basis) with this scenario where a patient who needs to have a
significant amount of oral contrast media and then (approximately one hour later) needs
to have a sedated CT scan of the abdomen. Do we refuse to sedate these patients? Do we
give “minimal sedation”? Do we ask for a rapid sequence intubation and a general
anesthetic?
In the interest of full disclosure we have to admit that there no consensus in our own
institution among those who provide sedation. Everyone would prefer not to sedate these
children at all. In cases where sedation is required, a differentiation is made between
extremely high risk patients (those with any intestinal obstructive symptoms or those with
marked gastroesophageal reflux) and otherwise well children. For those with high risk,
many prefer to protect the airway with an endotracheal tube while “well” children are
given sedation with a simple facemask oxygen. We have negotiated with our radiologists
that the oral contrast is given 2 hours before the study and we find that there is usually
little contents in the stomach at the time of the sedation. In some high risk patients with
proximal pathology, the radiologists will accept contrast placed through an OG tube after
an endotracheal tube is in place with a dwell time of 10-15 minutes. Each case needs to
be discussed with the radiologist who will be reading that particular study to determine if
this technique would be adequate for a given patient.
As most of our readers will recognize, there is very little clear (evidence based) data on
what the risk of aspiration is for children under sedation - in general. We could find no
such data for sedated CT scans with oral contrast. Reports from the emergency medicine
literature indicate that the incidence of aspiration during sedation (even in children
considered to be “full stomach”) is extremely low. On the other hand we must ask what
level of risk is acceptable for an elective CT scan?
In light of the current lack scientific studies, a consensus concerning current practice for
these studies may be the best we can do. We ask our readership (particularly radiologists)
– what are the issues in your respective institutions and how are these studies handled?
We will summarize the responses and publish summaries in the next newsletter.
Sedation Education:
Another interesting question came to us from a pediatric anesthesiologist at a children’s
hospital struggling with the question of how to “certify” sedation providers.
We do not have an anesthesia sedation team, and therefore,
have a variety of physicians providing sedation for a variety of
procedures. Our institution has decided that physicians need to be
"certified" through the credentialing committee to provide sedation.
It is my job to develop the "certification" process. I was curious as
to what you do at your institution and if you know what other
institutions are doing? Are there any standards that you know of? Are
there accepted educational materials (booklets, videos, etc.) for
purchase available?
We have developed our own sedation course that includes a written didactic portion, a
written test, and a hands-on simulator based practical session. Hospitals large and small
across the country are trying to come to grips with how to meet the new JCAHO
standards for training of sedation providers. As most of us are aware, while the standard
to provide training and certification exists, there is little in the JCAHO literature to guide
the formation of such a training course. We are not aware of proprietary courses available
at this time, but it would not make sense for every hospital across the country to develop
its own course as this would represent an incredible duplication of effort.
We invite our readers to inform us on what is being done at their institutions and to
provide information on any standardized sedation courses that are available. Once again
we will condense this information and send it out to you in a future newsletter.
Literature review:
George M. Hoffman, Rhonda Nowakowski|, Todd J. Troshynski, Richard J. Berens, and
Steven J. Weisman. Risk reduction in pediatric procedural sedation by application of an
American Academy of Pediatrics/American Society of Anesthesiologists process model.
PEDIATRICS Vol. 109 No. 2 February 2002, pp. 236-243
Abstract:
Guidelines for risk reduction during procedural sedation from the American Academy of
Pediatrics (AAP) and the American Society of Anesthesiologists (ASA) rely on expert
opinion and consensus. In this article, the authors tested the hypothesis that application of
an AAP/ASA-structured model would reduce the risk of sedation-related adverse events.
Methods. Prospectively coded sedation records were abstracted by a hospital quality
improvement specialist with practical and administrative experience in pediatric sedation.
Process variables included notation of nulla per os (NPO) status, performance of a guided
risk assessment, assignment of ASA physical status score, obtaining informed consent,
generation of a sedation plan, and assessment of sedation level using a quantitative
scoring system. Content variables included adherence to AAP NPO guidelines, ASA
class, target sedation level, actual sedation level, age, procedure, and drugs used.
Complication risk was assessed by logistic regression and Mantel-Haenszel odds ratios
(OR). Results. Complications were identified in 40 of 960 records (4.2%). The
complication rate was 34 of 895 (3.8%) with planned conscious sedation and 6 of 65
(9.2%) with planned deep sedation ([DS]; OR: 2.6). Complications were reduced by
performance of structured risk assessment (OR: 0.10), adherence to all process guidelines
(OR: 0), and avoiding actual DS (OR: 0.4). The only drug associated with higher risk was
chloral hydrate (OR: 2.1). Failure to adhere to NPO guidelines did not increase risk in this
assessment; however, the adverse event rate was 0 if all process guidelines were
followed. Conclusions. Presedation assessment reduces complications of DS. Repeated
assessment of sedation score reduces the risk of inadvertent DS. The data provide direct
evidence that AAP/ASA guidelines can reduce the risk of pediatric procedural sedation.
Commentary:
This study from the Children’s Hospital of Wisconsin clearly represents a first step
toward answering the long-held criticism of sedation guidelines – that adherence to a
specific set of recommendations has never been shown to decrease the risk of sedation.
For this effort alone all involved should be congratulated. This is a difficult task.
In summary, the investigators evaluated almost 900 sedation records and assessed
whether or not a standard AAP/ASA based structured model was followed. The records
were then evaluated for the presence of complications related to the sedation and
logistical regression methods were used to compare various factors relating to these
groups.
The authors begin by pointing out that adherence to practice standards has significantly
decreased risk in the general anesthesia setting and hypothesize that adherence to a
specific the AAP/ASA based structured model would similarly decrease the risk of
sedation by non-anesthesiologists in a children’s hospital setting. The study is quite
complex in its methodology and interested readers should review it in its entirety.
The discussion section is extensive and in it the authors recognize the strengths and
weaknesses of their own work and review the evidence for their conclusions.
As this study will no doubt be widely quoted and discussed we feel compelled to bring up
a few points that will certainly be raised as the merits of this study are debated:
1. While the abstract methods section starts with the terminology “prospectively coded
sedation records were abstracted” – this study boils down to a sophisticated chart review
of all sedations that took place in this institution during a several month period in 1999
(after a policy for a uniform sedation process was implemented). The weaknesses
associated with this type of study are well known and recognized by the authors in the
discussion section of the paper. The investigators are relying on accurate charting of
sedation data by individuals performing sedation who did not necessarily know this
information would be used as data for study analysis in the future – anyone who gives
sedation regularly knows this is a leap of faith. In addition, the methodology of this study
does not allow for blinding of the data gathering agent.
2. Readers must accept what is considered a meaningful “complication”. The study was
undertaken to evaluate the safety of sedation practice, yet there is a wide variety of issues
that are included under the heading of “complication” including “failed sedation” and
“inadequate sedation”. (The complications are divided into different groups but all are
used as part of the analysis.) Do some of these complications represent measures of
safety risk or process effectiveness? In addition, there were no episodes of temporary
injury, permanent injury, or death in any of the records - regardless of whether or not the
structured process was followed. In order to accept the idea that the structured process
really makes a difference for these important safety outcomes, we must accept that the
minor complications that lead to “process variation” or “care escalation” (such as
repositioning of the airway) are surrogate markers of greater risk. (i.e. we would have to
assume that if the authors evaluated a large enough cohort, serious outcome differences
would be evident in patients who experienced the complications that were observed).
3. As the study is not controlled or randomized, we can not be sure that patients who
were higher risk were not treated somewhat differently from the lower risk patients. As
the authors point out, although no relationship was found between aspiration risk and
“full stomach” status, these patients probably received a lesser degree of sedation because
of aspiration concerns.
4. This study represents data from only one institution. As we all recognize, pediatric
sedation practice is highly non-standardized from one institution to another; it is very
hard to conclude that the same findings would necessarily be present in another
institution with a much different “sedation culture”.
With these points in mind we feel this paper brings up many important points for
discussion and worthy conclusions. Just a few include:
1) Chloral hydrate patients were not only over-represented in the complication group,
there was also a significant rate of unintended deep sedation in this group despite
standard dosing regimens. 2) Patients who received multiple sedating medications were
over represented in the complication group. 3) The use of midazolam alone had a very
low complication rate. 4) The use of continuous (provocative) scoring of sedation level
was associated with a decreased risk associated unintended deep sedation. While we do
not debate these findings, we find provocative sedation scoring systems difficult to apply
clinically since we have to disturb a patient we would rather keep asleep in order to
accurately score the patient. 5) The use of a graded risk assessment tool was associated
with decreased risk for deep sedation. The exact elements of the tool may be less
important than the fact that thought was given to risk elements prior to sedation.
We feel this study represents an important first step in the establishment of a link
between guideline adherence and safety. It would be reassuring if the results were
confirmed by a prospective multicenter trial some time in the future.
Close Call and Critical Incident Reports
We invite those receiving the newsletter to submit cases to this "Close Calls" section
aimed at the key safety issues associated with providing pediatric procedural sedation.
The cases have been "sanitized" such that the date, patient identifiers, institutional
identifiers, provider information, etc. will not violate the privacy of the patient or care
providers.
Case #9
A 4yo child with a seizure history needed an MRI scan performed. At the reporting
institution, pediatric MRIs are performed by a sedation team consisting of an
anesthesiologist, RN, LN, and Child Life Specialist. The sedation team elected to induce
anesthesia with nitrous oxide and then sevoflurane without complication. Within 5
minutes an IV was placed, nitrous oxide and sevoflurane stopped and propofol started
intravenously. Since the patient was then going to be transported to the MRI scanner, a
pulse oximeter was placed and an external facemask applied. While a portable
capnograph unit was being applied, the child was noted to be deeply cyanotic and
resuscitation was initiated. Throughout this period of time, including the cyanosis, the
providers read the pulse oximeter display as a heart rate of 65 and a SpO2 of 98%.
To make matters worse, the monitor was beeping with each heart beat and maintaining a
constant tone with no alarm behavior.
After ventilation by face mask, the care team recognized that the SpO2 had been 65 and
the heart rate was 98 (the values had been misread and transposed). In addition, the team
did not realize that the portable monitor being used did not have behaviors that had
become standard for continuous pulse oximeter monitoring (a variable pitch beep that
correlates with SpO2, and a default alarm of 85% saturation).
After a brief period of positive pressure ventilation the child resumed spontaneous
ventilation as sevoflurane was exhaled and the propofol infusion reached steady state.
Comments: This case highlights important issues regarding standard of care for patient
monitoring when providing anesthesia, deep sedation, and moderate sedation.
1) Continuous monitors of ventilation and oxygenation. The concept that clinicians
cannot multi-task well means that looking at a patient for color or observing the chest for
respiratory excursions can only be done intermittently (one at a time). This is true for
visual monitoring and auditory monitoring. Modern pulse oximetry has been deemed a
continuous (rather than intermittent) monitor of oxygenation because: a) the tone
correlates with the SpO2 such that a decreasing saturation produce a tone of decreased
pitch. Click StandardPulseOx.wav to hear an example of standard pulse oximeter and
audio alarm; b) in addition default alarms must be set that provide both auditory and
often visual cues when a violation occurs (typically 85%-90% for a default SpO2 alarm;
in the example given, you can hear an audible alert and the display flashes yellow then
red); and c) there are often limitations on the ability of the clinician to disable these
alarms. The American Society of Anesthesiology has made continuous monitoring of
oxygenation a standard of care. The same principles can be applied for ventilation
monitoring using capnometry.
2) Intermittent monitoring: This terminology is used to describe spot-checking a variable
such as Blood Pressure on a regular interval (e.g., every 5 minutes). Intermittent
monitoring is not sufficient for early detection of events that can cause harm very rapidly
over the course of minutes.
3) The hazards of using a device in a manner that may not be consistent with the intended
use. In this case, the monitor in question was a portable pulse oximeter that is widely
used in the reporting institution and allows nurses to intermittently check HR and SpO2
for recording vital signs per the patient’s ordered time interval (e.g., VS Q4hrs, etc). The
default behavior of the pulse oximeter is to record for a short period, then shut off to
conserve battery life. However, since the device is very portable and can be made to stay
on and provide continuous readings, the institution was using it widely as a transport
monitor and a remote location monitor for sedation care. We actually use this device in
the same manner at our institution. We made a demonstration of the behavior of this
device using our pediatric simulator that you can watch (click URL
rtsp://april.dartmouth.edu:554/ray/PulseOximeter.rm to watch streaming video
recreation of SpO2 device described in scenario above). As you can see, this device
provides continuous recordings, but does not have a variable pitch tone that correlates
with SpO2, or default alarms. It rather chirps along at a constant tone as the SpO2
decreases to dangerously low
levels.
Conclusions: As a result of this report, we have alerted
anesthesia and other providers NOT to use these types of
pulse oximeters (that are designed to be INTERMITENT
monitors for checking vital signs on the floor) as a
CONTINUOUS monitor of oxygenation for
transportation, or off-site sedation care. We are only
using pulse oximeters and capnometers with default
alarms that visually and audibly alert a clinician (often
attending to other matters) to pay attention to a potentially urgent situation
Thanks for the reports that are being submitted, please keep them coming so that we all
can learn from them.