Patient Safety Tip of the Week
September 11, 2007
Root Cause Analysis of Chemotherapy Overdose
A root cause analysis has been
published on an unintentional chemotherapy overdose that gained the attention
of the Canadian media a year ago. This is an extremely well done RCA that has
numerous lessons learned and should be read by anyone involved in patient
safety, whether your facility is involved in cancer chemotherapy or not.
The RCA was coordinated by the
Institute for Safe Medication Practices Canada and utilized the Canadian Root Cause Analysis Framework
developed by the Canadian Patient Safety Institute, ISMP Canada, and Saskatchewan
Health. For those unfamiliar with that RCA framework, it is an excellent
comprehensive overview of the elements of a thorough RCA. It incorporates most
of the important elements of the more widely known Veteran’s Administration root cause analysis tools
and adds elements from a variety of other resources.
The case involved a 43 year old
woman who was being treated for an advanced nasopharyngeal carcinoma with a
chemotherapy protocol of high-dose fluorouracil and cisplatinum. The
chemotherapy was to be given intravenously by an infusion pump over a 4-day
period. However, the pump was inadvertently programmed to infuse the entire
contents over a 4-hour period instead. The patient died as a result of the
mishap.
The RCA clearly developed a
timeline and an understanding of what happened, then did a cause-and-effect
analysis, resulting in three causal chains and multiple associated findings or
incidental findings that are equally important in identifying opportunities to
improve patient safety.
The discussion on the causal chains
leading to incorrect programming of the infusion rate is excellent and focuses
on many of the individual issues we have mentioned in previous Tips of the
Week. The formula the bedside nurses had to use was incredibly complex and they
did not have at hand all the information needed to make the calculation. The
medication label not only had several features not in keeping with good human
factors design principles but also included unnecessary information that may
have increased the opportunity for false confirmation of the infusion rate. The
double check process did not catch the programming error and there was a lack
of feedback from the pump that further reduced the opportunity to notice the
incorrect infusion rate. The description about how several advanced
technologies were poorly integrated and actually led to increased cognitive
workload is particularly informative.
All the above occurred against a
background where the potential toxicity of the regimen and the lack of an
effective treatment for overdose did not appear to be fully appreciated by
numerous members of the healthcare team. Much had to do with the dearth of
published literature on fluorouracil overdosage.
Many of the most useful comments
pertain to the response to the incident. The recommendations expand upon some
of the important points we included in our July 24, 2007 Tip of the Week on an incident
response checklist. They also showed how multiple other individuals would have
had similar difficulties programming the pump and nicely illustrated how a
facility needs to assemble a representative group of end-users during the
pre-purchase phase of any investment in new technology in order to identify
potential usability and safety issues.
The recommendations made in the RCA
are well thought out and do take into consideration possible unintended
consequences. The recommendations extend well beyond the facility and include
recommendations for manufacturers, regulators, safety organizations, etc. A
followup to that RCA was also published in the August 20, 2007 ISMP Canada Safety Bulletin .
This is an excellent RCA and a
model for doing a good RCA. In fact, our sole criticism has to do with their
prioritization of causal statements. The treatment protocol design was ranked #15
on their list. We would have ranked it at or near the top of the list. A
high-reliability organization would assume that something could go wrong with
the infusion process and ensure that, if it did go wrong, irreparable harm
would not take place. We see this as akin to the concentrated potassium
chloride issue. We understand that convenience of the patient must have been
important in development of the chemotherapy protocol but inclusion of 4 days
worth of fluorouracil (plus a single high dose of cisplatinum) in a single IV
bag enabled the fatal outcome when subsequent errors occurred. A “safety
culture” would likely have said “what is the highest dose that a patient could
tolerate in one day (or less) if there was inadvertent administration of the infusion?”.
A safety culture would have designed the protocol with sublethal dosages that
would have protected the patient in the event of “what can go wrong will go
wrong”. It also would not have put the healthcare workers at the “sharp end” in
a situation none of us would want to be in.
All the people who contributed to
this excellent RCA are to be congratulated. This is clearly the type of
incident that could occur today at multiple healthcare facilities and provides
numerous useful lessons you all can use. You need to read it because many of
the same issues occur in processes your facility uses today. It’s also a great
teaching tool to use with your RCA Team or any multidisciplinary team involved
in patient safety.
Addendum: The September 20, 2007 Medication Safety Alert from ISMP
also includes a summary of this case.
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