Cases & Commentaries

X-ray Flip

Commentary By Marc J. Shapiro, MD

The Case

A 19-year-old man presented to the emergency
department with respiratory distress after blunt chest trauma. A
digital chest radiograph was labeled backwards; a "left" marker was
mistakenly placed over the right chest. There was a moderate
pneumothorax seen on the film on the anatomic left side (the side
of the aortic arch). On the radiograph, however, the pneumothorax
appeared to be on the patient's right (Figure).

The resident assigned to the patient performed a
brief physician examination, but based his localization of the
pneumothorax largely on the reading of the chest radiograph. He
thus placed a right chest tube. A correctly labeled follow-up chest
x-ray showed persistent pneumothorax on the patient's left and the
right-sided chest tube. A second chest tube was then placed, this
time in the patient's left chest. The patient remained stable. The
right chest tube was removed after the physicians confirmed that
there was no air leak. There were no further sequelae.

The Commentary

While sidedness errors often make dramatic
headlines, their incidence is difficult to determine based on
available epidemiologic studies.(1-3)
Wrong site surgery, one type of sidedness error, provides some
insight into the frequency of these adverse events. In December
2001, the Joint Commission on Accreditation of Healthcare
Organizations (JCAHO) issued a Sentinel Event Alert reporting 150
cases of wrong site, wrong person, and wrong procedure surgery. In
the year 2002 alone, more than 60 errors were reported—a
four-fold higher number of wrong site surgeries than reported in
1998.(4) The
"root causes" of these events are available online.

In a recent study looking at the incidence of
wrong site surgery among hand surgeons, 21% (217/1050) of
physicians reported having performed wrong site surgery at least
once in their career.(5) Of
an estimated 6,700,000 surgical procedures, 242 were performed at
the wrong site, making this a "rare occurrence."(5) Risk management databases might provide an alternative
source of information, but access to national data on claims is
difficult to obtain. In our large (approximately 600 beds), urban
teaching hospital, we have seen two wrong side invasive procedures
in the past three years. The actual incidence of wrong side
procedures is likely higher than published data as a result of
incomplete reporting of minor events without adverse

It would certainly be helpful to know the
magnitude of x-ray mislabeling and how digital radiography might
affect this error rate, but there are no reliable data on this
topic. While digital radiography could decrease the frequency of
labeling errors, this case illustrates that technology will not be
a panacea and may, in fact, create new error patterns. For example,
recent implementation of bar code medication administration at
Veterans hospitals was designed to reduce medication errors. While
it may be doing so, it has also had some negative consequences that
may ultimately lead to new types of adverse events.(6)

Case Investigation

Although it is easy to retrospectively identify
the two obvious human errors in this case—mislabeling and
incorrect interpretation of the x-ray—making real strides in
reducing medical errors requires that our community accept the
precept that active errors in human performance are inevitable in
complex systems.(7)
Similar to aviation, anesthesia research has stated that between
70%-80% of errors result from human factors.(8,9) Human factors, however, represent only the most
visible end result of a more complicated series of occurrences
leading to an adverse event. It is often less fruitful to focus on
assigning causality or "root cause" than to better define all the
contributing factors. The Adapted Organizational Accident Causation
Model (10) is
a good framework for incident investigation and provides a more
comprehensive understanding of why an adverse event occurred. By
identifying latent
errors related to organizational processes and other
contributing factors, it becomes more apparent where systematic
change is required.

Cognitive Errors

Trying to perform a cognitive autopsy to
understand why the resident committed the error is difficult
without a more detailed investigation into this incident. Did the
resident rely more heavily on the x-ray for localization and not
trust the physical examination or attempt to confirm the x-ray
finding with auscultation or another diagnostic modality? Perhaps
there was an error of overconfidence, a failure to recognize
his/her limitation in radiograph interpretation, or a reluctance to
ask for help due to an expectation of competency in what appeared
to be a straightforward diagnosis. We must improve training of
physicians to help them gain a better understanding of their
thought processes (metacognition) and
potential cognitive biases which affect clinical decision making.
Armed with this understanding, they can apply cognitive forcing
strategies to reduce the occurrence of diagnostic error.(11,12)

Possible Solutions

This case illustrates a need for specific
solutions. Hospitals must standardize the process for acquisition
and labeling of radiographs. In doing so, hospitals should strive
to implement a universal cognitive forcing strategy to always
verify that a radiograph belongs to the patient and is properly
oriented. Analogous to the solution for wrong site surgeries, a
required checklist and pre-procedure pause could serve as a defense
barrier in all but the most emergent cases. For example,
independent confirmation of location by two clinicians for all
blind procedures or those involving laterality should be standard
operating procedure. Additionally, with chest tube or
thoracentesis, there should be a confirmation by a minimum of two
methodologies, such as auscultation, radiograph, or ultrasound.

This case serves as a caution for health care
leaders that technology systems alone will not eliminate errors in
health care institutions. The movement away from the 'person' model
of error—'blame and train'—to a focus on systems is
necessary, but we must balance our safety programs to ensure human
factors training exists for front-line clinical personnel. To
create a grass roots cultural change, we must translate the general
tenets of a "high reliability" organization—(i) preoccupation
with failure avoidance, (ii) reluctance to simplify
interpretations, (iii) sensitivity to operations, (iv) commitment
to resilience, and (v) deference to expertise (13)—into meaningful curricula in areas such as
cognitive decision making and teamwork.(14) Training in team dynamics, communication skills, and
interpersonal behaviors should concentrate on encouraging all team
members to cross-monitor each other, exert situational leadership,
and assert corrective actions to reduce error.

J. Shapiro, MD
Director, Rhode Island Hospital Medical Simulation Center
Assistant Professor, Brown Medical School


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Figure. Representative Chest X-ray*

*Not the actual radiograph. The red arrow
indicates the aortic arch. The yellow arrows indicate the outline
of the pneumothorax.