Cases & Commentaries

Getting to the Root of the Matter

Spotlight Case
Commentary By Scott A. Flanders, MD; Sanjay Saint, MD, MPH

Case Objectives

  • Appreciate the goals and limitations of
    root cause analysis
  • Outline the steps to conduct root cause

The Case

A 65-year-old man with atrial fibrillation,
lung cancer, and chronic renal insufficiency presented to the
emergency department (ED) with shortness of breath. His vital signs
were significant for a respiratory rate of 32, a temperature of
102.4°F, and an oxygen saturation of 87% on a 100%
non-rebreather. A chest X-ray showed a right middle
infiltrate. Due to respiratory distress, the patient was

Shortly thereafter, the patient became
hypotensive with a systolic blood pressure (BP) of 65 mm Hg. Fluid
resuscitation was continued while BP was supported with
phenylephrine and vasopressin. Phenylephrine was changed to
norepinephrine. After 8 hours, arterial blood gas test revealed a
pH 7.23, Pco2 23 mm Hg, Po2 161 mm Hg and
base excess –16, lactate 6.2 mmol/L (normal 0.5 – 2.2
mmol/L). A pulmonary artery catheter was placed, and initial
numbers were—surprisingly—more consistent with
cardiogenic shock than septic shock, with a central venous pressure
of 13-17 mm Hg, pulmonary capillary wedge pressure of 19 mm Hg,
cardiac index (CI) 1.8 L/min/m2, and systemic vascular
resistance (SVR) of 1500 dynes/sec x cm-5.
Norepinephrine was weaned rapidly. The patient remained on
vasopressin. An echocardiogram showed global decrease in
contractility, with an ejection fraction 45% and mild right
ventricular dilatation. Shortly thereafter, it was discovered that
the patient had been receiving 0.4 units/min of vasopressin, rather
than the intended dose of 0.04 units/min. Vasopressin was

Within the next few hours, the patient’s
condition improved. The CI and mixed venous oxygen saturation
increased to 3.8 L/min/m2 and 75%, respectively, and the
SVR decreased to 586 dynes/sec x cm-5. A creatine kinase
(CK) peaked to 7236 U/L, CKMB to 37 U/L. The patient was treated
with fluids and antibiotics and had an uneventful recovery.

The Commentary

A patient admitted to the intensive care unit
(ICU) with septic shock requiring vasopressors appears to have
suffered a myocardial infarction (MI) in the course of his
treatment. While not terribly surprising, the cause of the MI was
likely related to a log increase in the dose of vasopressin because
of a prescribing error. This, too, is unfortunately not surprising.
Clinicians who regularly care for hospitalized
patients—particularly the critically ill—often observe
medical mistakes. The magnitude of medical error, the relative
contribution of errors to adverse patient outcomes, and the
decision to devote substantial resources to prevent errors of
unclear significance are often debated.(1) Few,
however, would argue that the error in this case should not be
investigated. How would you do it? What would you be likely to
find? What solutions could be implemented?

Root Cause Analysis

This error would likely have generated a root
cause analysis (RCA) if it had occurred in the institutions in
which we practice. In health care settings, RCAs are investigations
of serious adverse events (or occasionally close calls) performed
by a team with expertise in the area of investigation whose members
were not directly involved with the error. The team’s goal is
to determine what happened, why it happened, and what can be done
to prevent it from happening again. Rather than focus solely on the
individual who wrote the incorrect order, the RCA broadens the
focus to examine the “root causes” of the error. Thus,
a proper RCA includes an assessment of the environment (e.g., time
of day, staffing levels, lighting, product storage and labeling,
medication ordering process) in which the error occurred. The
theory underlying an RCA is to move the understanding of adverse
event analysis away from individual human mistakes that are less
actionable to a human factors engineering approach that looks for
systems vulnerabilities.(2)

The Investigation

Performing an RCA based on an anonymously
submitted case is virtually impossible. Proper system analyses
require direct observation of the work environment, interviews with
key staff involved in the error (to establish a chronological flow
of events), careful review of incident reports from the same ICU
looking for similar episodes (or near misses), and intimate
knowledge of the institution that would allow for reasonable
proposals for change.

We do have a small amount of additional
information from this event available to us to review. Pertinent
facts include (i) a verbal direction was given by the fellow to the
resident to order vasopressin; (ii) the resident directly entered
the order into a computerized physician order entry (CPOE) system,
which had a menu of several possible doses of vasopressin; (iii)
the error went undetected for more than 16 hours; and (iv) the
error persisted through the next day’s multidisciplinary team
rounds, which included physicians, nurses, and possibly
pharmacists. In addition, we know that the error was discovered
when one of the ICU nurses brought a group of nursing students to
the patient’s bedside for an introduction to critical care
nursing. She pointed out to the students that the patient in this
case was receiving the medication vasopressin, at a dose of 0.4
units/min. The ICU fellow, overhearing her instruction, corrected
her, saying, “No, the patient is on 0.04 units/min.”
The fellow then confirmed the dose with the patient’s nurse
and found that the patient was, in fact, on the higher dose.

Although the information is limited, we will
nevertheless attempt to perform an RCA as if this error occurred in
our hospital.

Getting Started

The RCA team is usually led by a member of the
institution’s patient safety or quality improvement program
who has expertise in conducting these analyses. This individual is
responsible for ensuring that the process focuses on systems,
rather than individual, actions. For a case such as this, other
members of the team should include an ICU physician, as well as
representatives from ICU nursing (both the nurse manager and a
staff nurse), the pharmacy, and the ED (where vasopressor
medications are often initiated). Importantly, an ICU fellow as
well as a medical resident who has recently rotated through the ICU
should also be a part of the RCA team.

Gathering Data

Once established, the RCA team generates a
differential diagnosis for systems factors that may have
contributed to the error. The Table outlines
investigation domains generated in this case after considering the
myriad underlying causes of the error. Ultimately, each domain is
assessed for contribution to the error and priority for change. The
first step in this process is to develop a timeline of events
related to the patient’s care. As much as possible, every
provider contact with the patient (from physician to patient
transport personnel), every order, every test, and every response
to a test should be charted. The timeline can be used to observe
all the steps involved in the care of the patient and better
evaluate what contributed to the incorrect dose being administered.
Based on additional data provided by the case submitter and our own
experience, the most important contributing factors were:

  • There were no ICU protocols for
    high-risk procedures or for the use of high-risk drugs;
  • There was poor staff/trainee teamwork
  • There was no systematic process in the
    ICU for reviewing key aspects of patient care during daily
  • There were no nursing guidelines or
    protocols for use of vasopressor medications; and
  • There was no process in the pharmacy to
    highlight medications used in differing doses for different

Analyzing Contributing Factors

Most ICUs emphasize high quality and safe care;
increasingly, ICUs are committed to creating a culture of safety.
While many ICUs have developed processes and protocols related to
high-risk procedures such as central line insertion or endotracheal
intubation, in our experience, few have done the same for high-risk
medications. Preventable adverse drug events are a common type of
error seen in the ICU setting.(3-6) One recent
study of errors associated with long ICU work hours concluded that
medication errors were the most common mistake seen.(7) Fortunately,
most errors are caught, and those that are missed usually do not
lead to adverse outcomes. However, this may not apply to certain
high-risk medications (e.g., intravenous potassium chloride or
insulin) (4),
justifying a more aggressive approach toward preventing errors
in their use
. We believe that vasopressin should be considered
a high-risk medication, since it has a narrow therapeutic window
and is known to cause the serious adverse cardiovascular effects
seen in this patient when recommended doses are exceeded.(8,9) As a
result, most guidelines and systematic reviews of the use of
vasopressin for septic shock do not recommend it for use as a
first-line vasopressor, and, when used, recommend it be started at
very low doses and not be titrated above 0.04 units/min.(10) All ICUs
should have protocols in place to handle such high-risk
medications. This ICU did not.

The vasopressin order was incorrectly written by
a resident physician after he received a verbal order from his
supervising critical care fellow. A full discussion of issues
related to the human factors and teamwork problems in this case is
beyond the scope of this commentary but has been reviewed in a past
WebM&M case.(11) Although we
do not know exactly what the fellow said to the resident, it is
unlikely that the fellow asked the resident whether he understood
the order, had used vasopressin previously in patients with septic
shock, or had concerns about writing an order for this particular
drug. We suspect that only a handful of teaching hospitals
routinely require that verbal orders given by a supervising
physician be “read back” by
the trainee.

The ICU physician rounding process, while very
structured in time and clinical content, rarely includes a regular
assessment of medication doses, drug interactions, or key error
prevention and patient safety steps (e.g., daily assessment of the
need for continued venous or urinary catheterization).(12)
Additionally, pharmacists may not regularly round with the team or
routinely review all prescribed medications; such rounding has been
demonstrated to be associated with a reduction in medication
errors.(13) Finally,
trainees should be taught that the differential diagnosis for
unusual clinical findings (such as the pulmonary artery catheter
revealing cardiogenic shock in this case) should be expanded to
include iatrogenic causes such as medication error.

The nurse caring for this patient administered
the incorrect dose of vasopressin. In fact, the incorrect dose was
given for more than 16 hours, which means that more than one nurse
was involved in the error. It was not until a nurse was discussing
the medication dosing with nursing students that the incorrect dose
was overheard by the fellow and the error recognized. Although it
is tempting to lay the blame entirely on a lack of knowledge about
vasopressin, the focus on systems and environmental issues would
likely reveal that nurses in this ICU did not follow set protocols
related to the use of vasopressors, did not systematically review
doses of medications during nursing sign-out, and—in contrast
to what happens with blood transfusions—did not regularly use
a process of “double-checking” whether the right drug
is being given to the right patient at the right dose.

Pharmacy issues also figured prominently in this
error. The institution had a computerized physician order entry
(CPOE) system, but, as has been noted previously (14), merely
implementing a CPOE system or a patient bar coding system will not
eliminate medication errors. In this case, vasopressin was
available in two doses in the CPOE system. A dose of 0.04 units/min
was available for treating shock, and 0.4 units/min for
gastrointestinal hemorrhage and variceal bleeding. This CPOE
system, like most at this point, did not ask for the indication,
nor did it flag the order for pharmacist review despite the known
risks of the higher dose of vasopressin.

Systems Solutions

Unfortunately, we have no randomized trials of
safety solutions to help guide the changes that need to be made. We
thus must rely on the data generated by the RCA to identify the key
steps that contributed to the error, propose reasonable
systems-based solutions, implement the changes, and then
re-evaluate the process to ensure we have not created more problems
than we have solved. In this case, we would propose the following

  • Most institutions respond to such errors
    by patching small leaks in the systems that have created the error.
    Some have argued that the most important and most long-lasting
    changes result not from patches, but from complete system
    redesign.(4) We agree.
    Most institutions, however, are reluctant to commit the resources
    and effort required for such changes. In this case, a
    multidisciplinary team could redesign the entire medication
    delivery process in the ICU. The process could include complete
    medication reconciliation and review at patient entry and exit into
    the ICU, an intervention that is beginning to occur at some
    institutions.(15) An ICU
    safety officer (or pharmacist, if only focusing on medications)
    would round with the team, reviewing all medications (indication,
    dose, interactions) as well as other non-medication-related patient
    safety measures (e.g., urinary and vascular catheter management,
    elevation of head of bed in mechanically ventilated patients,
    prevention of venous thromboembolism). At minimum, a review of
    medications and doses by the team should happen every morning
    (perhaps twice daily in an ICU) on rounds and should include a
  • High-risk medications need to be treated
    similarly to high-risk procedures. Perhaps there should be
    “time outs” prior to high-risk medication
    administration, similar to what happens with blood transfusions, to
    ensure we are giving the correct medication to the correct patient
    at the correct dose. In the case of vasopressors, standard dosing
    scales that attempt to prevent overdoses should be programmed into
    IV pumps.
  • Adopting processes from the aviation
    field, teamwork training should be considered for all physicians,
    nurses, trainees, and other staff who work in the ICU. Such
    training would include role-playing and simulations that markedly
    improve team dynamics and communication.
  • A forum should be created that allows
    residents, fellows, nurses, pharmacists, and other team members to
    openly discuss errors. Such discussions could take place during an
    occasional morning report or a morbidity and mortality conference.
    This will increase the likelihood that constructive changes will be
  • The CPOE system should remind the
    ordering physician that a drug such as vasopressin (and others like
    it) has more than one indication, and then it should query the
    indication and provide a suggested dose. Computer-generated
    recommendations that are overridden by the physician ideally would
    be flagged for immediate pharmacist review. In addition, smart
    systems could include admitting diagnoses and, by combining that
    with patient location (ICU or ward), flag a drug or dose as
    potentially incorrect, thereby triggering a review.

The RCA: Important Limitations and

Although the value of RCA has not been confirmed
in carefully conducted clinical trials in a health care
environment, we believe that these analyses serve a useful purpose
in error reduction when used appropriately. RCA works best in
assessing rare events—such as wrong-site surgery or egregious
medication misadventures that lead to fatal overdoses—rather
than common patient safety problems (e.g., hospital-acquired
infection, contrast-induced nephropathy, delirium in a hospitalized
patient) that are more amenable to an approach based on principles
of clinical epidemiology (i.e., surveillance, benchmarking,
intervention, re-evaluation).(18) Proposed
system-based solutions need to be feasible. There are no greater
barriers to changing safety culture than those created by silly,
time-consuming, and ineffective safety protocols, especially those
developed by managers who no longer are clinically engaged in the
tasks they are modifying. Asking clinicians to jump through
bureaucratic hoops in the name of patient safety squanders the good
will of the staff, thereby making useful error-reduction strategies
challenging, if not impossible, to implement. We thus believe that
nearly all clinical leaders—nurse managers, safety officers,
physician executives—should be required to perform some
clinical work in the setting they are managing. Finally, we suggest
that all changes be re-evaluated periodically to ensure the new
process is indeed safer and achieving the desired outcomes.

Scott A. Flanders, MD
Director, Hospitalist Program, University of Michigan Health
Clinical Associate Professor of Internal Medicine, University of
Michigan Health System

Sanjay Saint, MD, MPH
Research Investigator, Ann Arbor VA Medical Center
Associate Professor of Internal Medicine, University of Michigan
Health System
Director, VA/UM Patient Safety Enhancement Program


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Table. Investigating the Error

Domain of Investigation

Contribution to Error

Priority for Change


Timeline of events



ICU protocols for high-risk processes/use
of high-risk medications

No checks and balances for high-risk


Division of labor between ICU/ER for
patients admitted to ICU

Unclear: Incorrect doses ordered in ER
may persist after transfer to ICU: NC


ICU safety culture

No focus on routine prevention


ICU environment (lighting, layout,



Physician/Resident Practice

Medication ordering process

Unclear roles and expectations for


Communication practices

No “read-back” on verbal


Staff/trainee working relationships

No teamwork training/unclear roles/no use
of simulation


Supervision of trainees

No routine assessment of


Trainee work hours

Work hours mandated: Unclear


Knowledge assessment

No formal training/guidelines for pressor


Rounding practices

No systematic review of



Staffing levels

Adequate: NC


Management support/training

Supportive environment/regular
orientation for new nurses: NC


Infusion practices

No specialized infusion pumps for


Protocols for pressors

No nursing guidelines/no


Task design and clarity

Process for administering meds not
standardized/no formal design



Where/how meds stocked

Different doses of drug drawn from same


How are meds ordered/delivered

CPOE (no hand-writing issues)/pressors
drawn up in ICU, not pre-mixed


How are meds with different doses for
different indications handled

No computer alert for different
doses/different indications


How are dose errors communicated when

No routine system for suspecting
errors/communication is pharmacist dependent


N/A: non-applicable; NC: non-contributory.

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