- Discussion:
- malignant hyperthermia of anesthesia is autosomal dominant condition;
- it is rare disorder that appears to involve excessive release of calcium from
sarcoplasmic reticulum in response to anesthetic agents;
- neuromuscular pts (eg
DMD), esp those with are more susceptible to malignant hyperthermia, a chemically induced genetic myopathy;
- malignant hyperthermia may occur w/ use of
succinylcholine & halothane;
- dx requires a muscle biopsy, the caffeine-halothane contracture test remains the best way to screen for susceptibility;
- Clinical Manifestations:
- severe muscular rigidity and
rhabdomyolysis;
- body temperature rises, often at an alarming rate;
- hypotension, profuse tachycardia and other arrhythmias, hypoxia, hypercapnia;
- Labs:
-
metabolic acidosis (
lactic acidosis),
hyperkalemia, and DIC;
-
elevated CPK
- Treatment:
- prompt treatment of malignant hyperthermia is esstential;
- body temp may be lowered w/ cooling blanket, iced IV, & ice packs;
- intermittent
ABG and bicarbonate as appropriate for metabolic acidosis;
-
insulin and
glucose are provided as appropriate for
hyperkalemia;
-
Dantrolene: 1 mg/kg/min upt 10 mg/kg/min;
- continue until all symptoms have resolved for 6 hours;
- r/o coagulopathy;
- beware of myoglobinuria and resulting renal failure; (see
rhabdomyolysis)
Malignant hyperthermia. DH MacLennan and MS Phillips. Science. Vol 256. 1992. p 789-794.
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