3 4
S U P P L E M E N T T O O U T P AT 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 | O C T O B E R 2 0 1 4
Answer
: a
Dantrolene is a skeletal muscle relaxant that impairs calcium dependent muscle
contraction and controls the hyper-metabolism associated with an MH event. It
directly interferes with muscle contraction to decrease calcium — which is
increased during an MH episode — in muscle cells.
Initial dosing with dantrolene is _____________.
a.
1 mg/kg
c.
2.5 mg/kg
b.
10 mg/kg
d.
25 mg/kg
Answer
: c
Dantrolene 2.5 mg/kg administered rapidly through a large-bore IV is the recom-
mended initial dose for patients experiencing an MH event. The upper limit rec-
ommendation is a dose of 10 mg/kg. Traditional forms of the medication are
supplied in 20 mg vials and must be reconstituted with 60 ml of preservative-
free sterile water and vigorously shaken to completely dissolve. There is also a
new brand of dantrolene that offers quicker reconstitution and higher doses per
vial, and that has different instructions for administration.
When MH strikes, discontinue the administration of volatile anesthetic agents
and succinylcholine, change the anesthesia breathing circuit, hyperventilate the
patient with 100% O
2
, apply bags of ice to initiate surface cooling and begin mix-
ing and administering dantrolene.
You should have ______ vials of dantrolene
immediately accessible to deliver the initial dose.
a.
24
c.
36
b.
32
d.
42
M A L I G N A N T H Y P E R T H E R M I A
