M
alignant
hyperthermia
episodes have
been estimat-
ed to occur in
the general patient population in
1 out of 100,000 administered
anesthetics. Even though MH is
rare, being ready and prepared
to handle a crisis is essential.
However, there are many myths
about MH that confound aware-
ness about the disorder and the
best possible treatment meth-
ods. Based on my experience as
the former medical director of
the Malignant Hyperthermia
Association of the United States
(MHAUS) hotline, these com-
mon misconceptions about MH
need clarifying.
MYTH #1:
A post-op fever is indicative of MH
FACT: Many clinicians worry that MH may begin in
the postoperative period with a fever as the present-
ing sign, and anesthesia providers are typically
taught that MH can occur as late as 48 hours after
surgery. This is incorrect. Postoperative hyperther-
mia (a temperature > 38°C) without additional signs
of MH is relatively common and is not typically
associated with an eventual diagnosis of MH. Nearly
all cases of postoperative MH begin to demonstrate
signs of onset within 10 minutes of discontinuing
the triggering agent (volatile anesthesia gas).
MYTH #2:
A high fever many hours
after administration of succinylcholine
is a symptom of MH
FACT: A common call we received on the MHAUS
hotline involved scenarios similar to this one: An
elderly patient with underlying respiratory disease
presents to the emergency room with pneumonia
and respiratory distress. The docs there determine
the patient is in respiratory failure and requires tra-
cheal intubation. Etomidate and succinylcholine are
administered, intubation is performed and the
patient is sent to the intensive care unit to receive
further treatment. Later that night, the patient devel-
ops a high fever, sometimes exceeding 40ºC. The
ICU staff believes a patient with a high fever who
received succinylcholine could be experiencing MH.
Although the administration of succinylcholine
alone is rarely associated with MH, there are no
known cases where MH begins to develop many
hours later — and manifest solely as a high fever —
without additional signs of MH. This patient's
uncommonly high fever is most likely related to
their underlying infectious process. We are not
aware of any of these cases that ultimately proved
to be caused by MH.
A U G U S T 2 0 2 0 • O U T P A T I E N T S U R G E R Y . N E T • 4 1
Malignant Hyperthermia Myth-Busting
Refuting common misconceptions about the rare disorder
will give your staff the knowledge they need to keep patients safe.
Ronald Litman, DO, ML I Philadelphia
EXPERT OPINION Ronald Litman, DO, ML, became familiar with common questions about MH during his time as the
medical director of the MHAUS hotline.
