- 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.