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analysis using the example of a patient who experiences a postoperative pulmonary
embolism, which was used in the Five Whys section.
In this fault tree analysis example, several errors contributed to the patient having
a pulmonary embolism. The patient was not on VTE chemoprophylaxis, which was
due to a human error in entering the order, but there should have been safety checks
in place including an alert to the physician that no VTE chemoprophylaxis was
ordered for the patient, and it should be listed in the standard order set for postop-
erative patients if the standard of care is to put patients on VTE chemoprophylaxis.
An additional risk factor for the patient developing a pulmonary embolism was his
immobility immediately postoperatively. While patients may typically ambulate
postoperatively, this patient was not transferred to the floor until the late evening
when the standard practice on the floor was to allow patients to rest, rather than to
encourage them to ambulate. Knowing that this patient was at increased risk for a
VTE event, the physician caring for the patient might have specifically asked the
patient and the nurse caring for him to ambulate several times before going to bed.
Lastly, this patient experienced an intraoperative complication of acute blood loss
that was due to an incorrectly placed suture on the venous plexus that later became
dislodged and led to significant bleeding. This led to an operative time that was
longer than average, conferring additional risk to the patient. Although this was due
to a technical error, further assessment may reveal that a different kind of suture or
technique may prevent this from happening in the future.
In 2012, Smith et al. reported their experience with a departmental initiative to
implement a QI program in the Internal Medicine Residency Program at Mount
Post-operative
pulmonary
embolismPatient not given VTE
chemoprophylaxis post-
operativelyVTE
chemoprophylaxis
not orderedResident entering orders
forgot to order VTE
chemoprophylaxisVTE chemoprophylaxis was not
listed in the standard post-operative
order setsPatient not ambulatory
post-operativelyDue to prolonged
operative time,
patient did not
arrive to floor until
late eveningLonger than average
operative timeDuring closing of laparoscopic
ports, active bleeding
discovered requiring additional
investigationSuture ligation of venous
plexus loosened leading to
significant bleedingFig. 11.4 Example of Five Whys analysis applied to postoperative pulmonary embolism
S. Helo and C. Welliver