anesthesiology and pediatrics at the Perelman School of Medicine at
the University of Pennsylvania and an anesthesiologist at the
Children's Hospital of Philadelphia, the key to an effective response is
knowing what you're up against, as he told us in a recent interview.
• On the line with emergencies. The calls the hotline gets are all differ-
ent. Sometimes they're handled calmly, in a focused way. Sometimes
they're very chaotic. We get a fair share of real cases, about 1 to 3 a
week, about 75 cases a year in North America. There may, of course,
be more cases we don't get called on.
• Anticipating adverse events. We also get a lot of practical calls that are
not emergencies, but are asking how to prepare. Another typical call
with a difficult answer is whether a high-risk patient whose family is
distant, and who doesn't have records available, and who hasn't been
tested, is susceptible to MH. We tend to respond on the side of cau-
tion, that they are. The only way to know for sure, though, is the con-
tracture test, which involves a muscle biopsy and which can only be
obtained at 5 centers in North America. Susceptibility can only be
ruled out if the test comes back negative.
• Warning signs of MH. Muscle rigidity in all extremities is a telltale
symptom of malignant hyperthermia, especially when you've already
administered a muscle relaxant. It can appear that they're shivering
vigorously, but if they've been given a paralytic agent, they won't be
able to shiver.
• Incorrect identification. Perhaps the most common misstep witnessed
by hotline consultants is OR staff thinking it's MH when there are other
causes for the symptoms they've observed. For example, hypoventila-
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O U T PAT I E N T S U R G E R Y M A G A Z I N E O N L I N E | January 2015
