Cases & Commentaries

Glucose Roller Coaster

Commentary By Bradley A. Sharpe, MD

The Case

A 71-year-old woman with congestive heart failure
was admitted to the hospital. Her medical history was significant
for dialysis-dependent, end-stage kidney disease and coronary
artery disease. She did not have a preadmission diagnosis of

While in the step-down unit on the evening of
admission, the patient had a routine phlebotomy sample drawn, and
the blood sugar level was 674 mg/dL. At 11:30 pm, the nurse
notified the covering intern, who telephone-ordered 10 Units of
regular insulin to be given subcutaneously. At 1:10 am, a
finger-stick glucose level was 50 mg/dL, and the intern verbally
ordered 1 amp of D50 to be given intravenously (IV). At 3:00 am, a
phlebotomized specimen revealed a glucose level of 19 mg/dL, and
the intern verbally ordered another amp of D50 IV, as well as a D10
drip. At 5:27 am, a finger-stick glucose was 99 mg/dL. At 11:00 am,
a phlebotomy sample revealed a blood glucose level of 351 mg/dL.
Another covering intern was notified, and 8 units of regular
insulin were ordered to be given subcutaneously. At 3:40 pm, the
patient was unresponsive, and a finger-stick glucose level was 13
mg/dL. Two amps of D50 were verbally ordered, and follow up finger
sticks were in the normal range.

Later, it was discovered that many of the
phlebotomy specimens had been drawn above an IV line infusing
dextrose solution. The step-down nurse was re-educated regarding
blood draws in relation to lines. Despite multiple episodes of
hypoglycemia, all subsequent glucose levels were normal and this
patient suffered no lasting harm.

The Commentary

Although multiple factors contributed to this
patient's roller coaster glycemia (Figure 1), her case highlights the challenges and
perils of "cross-coverage," the management of patients by
physicians other than those primarily responsible, and the
limitations of "signout," the transfer of patient data and care
responsibility when the primary physician goes off-duty.

From a resident's perspective, cross-coverage is
hard. The most challenging aspect is obvious and inherent:
residents must make clinical decisions about unfamiliar patients,
often with inadequate information. Without a complete history, a
physical exam, and a full assessment of a patient's problems,
providing high-quality care is challenging. Published literature
supports this notion: discontinuity, and by definition,
cross-coverage, in the care of hospitalized patients can lead to
increased lengths of stay, in-hospital complications, and
preventable adverse events.(1-3)

Cross-coverage is not only inherently difficult,
but it occurs when many other duties and tasks are vying for
residents' attention. Cross-coverage responsibility is often added
to the need to care for their patients. Alternatively,
cross-coverage is sometimes organized as a stand-alone role (such
as in "nightfloat"), but in these circumstances the demands are
often high. On the internal medicine service at our institution,
for example, the on-call interns provide some early evening
coverage during the busiest admitting time of the day. Moreover,
our nightfloat intern may be responsible for as many as 40-60
patients (including some in the ICU) and can expect to receive 5-20
pages per hour. Clearly, it is impossible to directly evaluate each
patient or review each chart when called. Therefore, inexperienced
residents are often asked to prioritize and triage patients with
limited or inadequate information. We are not told in this case if
the interns were sleeping in their call rooms or busy admitting
patients, but it is a safe bet that they had other patient care
responsibilities. In this setting, significant or potentially
life-threatening problems, like hypoglycemia, are often managed
over the phone, which can lead to poor outcomes, as seen here.

Cross-coverage is common in modern medical
training programs. At our institution, residents spend 2-4 weeks
out of each year in a cross-cover or "float" capacity; we know of
other programs in which residents spend even more time in these
roles. Adding up all the "floating" (particularly since the
implementation of the ACGME duty hours limitations [4]), this type of duty can consume as much as 20% of a
resident's inpatient training.

However, despite potential implications for
patient safety and medical errors, cross-coverage is not viewed as
a fundamental or core component of medical education. Residency is
filled with didactics on atrial fibrillation and preeclampsia, but
no structured training in efficient triage and quality care of
unfamiliar patients. Nightfloat interns typically don't receive any
structured orientation, and are often told to "Just keep 'em alive
until the morning." When called about patients they are covering,
residents and interns may view it as a nuisance or interruption in
their other duties, regardless of the clinical situation. In this
culture, it is not surprising that a busy intern with limited or
inadequate knowledge of a 71-year-old with heart failure would be
tempted to manage her care with reflexive verbal orders without a
more thorough evaluation.

Minimizing patient risk in this setting is
challenging. The attending could invest time teaching the interns
involved about inpatient problem triage and proper signout, but
reprimanding individual housestaff cannot be the only solution.
Raising individual awareness about the inherent risks involved in
information and patient care transfer is beneficial, but reliance
on individual provider vigilance and performance has been
Instead, efforts should focus on modifying the culture of
cross-coverage at academic institutions. Clearly, more time and
energy could be dedicated to structured training in the management
of acute conditions in unfamiliar patients, as well as to patient

The signout process itself can be improved. The
transfer of information between two individuals, whether between
control tower and pilot or two physicians, creates an opportunity
for miscommunication and errors in judgment, even under the best
circumstances. Adding to the risk, resident signout is often
performed in a haphazard, unstructured fashion—30 seconds in
an elevator or two sentences on the phone while walking out the
door—which can lead to forgetfulness and error.(6)
Standardization of communication, employed in the airline industry,
is one potential solution. Checklists (7) and signout cards (8) may
decrease the risk of error and improve the satisfaction of the
housestaff. Information technology—including computerized
signouts (9), an
easily accessible medical record, and computerized physician order
entry—can improve the quality of data transferred and allow
for better informed cross-coverage.

However, improving signout at an institution does
not require the installation of sophisticated, complex, and
expensive electronic medical records or technology. At UCSF Medical
Center, for example, our full-fledged, hospital-wide computerized
physician order entry system is presently being implemented.
Nevertheless, we have accomplished two interventions at a
reasonable cost that have markedly improved signouts and allowed
housestaff to learn key information about cross-coverage patients
without the ritual of rifling through stacks of index cards
(assuming the cards can be located at 3 am). The first is
alphanumeric text paging. Nurses and others now can easily look up
residents' names on a web site, write a short message, and send it
to their pagers. We estimate that 75% of pages are informational
only; freeing the resident from having to stop what he or she is
doing, find a phone, and return a page (which might be for anything
from a "just wanted you to know that I have drawn Mr. Smith's
potassium" to "Mrs. Jones looks like she might code in the next few
minutes") allows the residents to prioritize their time, minimize
their distractions, and provide better cross-coverage.

The second important intervention at our
institution has been the development of a computerized signout
program. Although some commercial programs are available, our
residents wrote their own program in a database format. Housestaff
now create and update signout sheets on every patient, and the
system is available at computers around the institution. Residents
can also transmit requests to schedule tests or discharge
appointments to ward clerks. Figures
2 and 3
show screen shots from the system. We are in the
process of migrating the system to the web, creating a portal for
nurses to access the records and input requests and concerns, and
allowing the system to communicate with wireless devices. Although
the ideal system will link to a robust electronic medical record
(and draw information like medication lists and lab results from
it), this standalone system is a practical, relatively inexpensive
solution to the clear and present danger of cross-coverage

Fortunately, this patient did not suffer any
long-term consequences. In this case, patient unfamiliarity,
inadequate signout, time limitations, and the institutional culture
surrounding cross-coverage likely influenced the interns'
management. No solution is foolproof. Nonetheless, improving
training in cross-coverage, standardizing the signout process, and
using information technology may allow practitioners to bridge
these gaps.

Take-Home Points

  • New ACGME duty-hour requirements are
    increasing resident cross-coverage, signout, and discontinuity of
    care for hospitalized patients.
  • Errors during cross-coverage are often
    due to patient unfamiliarity, other work burden, resident fatigue,
    and decreased supervision.
  • Improving training in cross-coverage,
    standardizing the signout process, and using information technology
    may decrease the error rates of signouts.
  • Although robust, institution-wide
    informatics solutions are ideal, alphanumeric paging and standalone
    signout database systems are two examples of relatively simple,
    inexpensive interventions that can improve signouts and
    cross-coverage while more expensive and complex systems are being

Bradley A. Sharpe,
Assistant Clinical Professor
Assistant Chief of the Medical Service
University of California, San Francisco


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Figure 1. The Glucose Roller Coaster

Figure 2. Front Page of Computerized Signout

Figure 3. Blank Computerized Signout