Presented by Joshua Ward Rare, life-threatening condition triggered by drugs used for general anesthesia Causes uncontrolled increase in skeletal muscle metabolism Susceptibility is inherited as autosomal dominant disorder Early signs Hypercapnia Tachycardia Masseter muscle rigidity Late signs ECG changes, arrhythmias Rhabdomyolysis Hyperthermia Intubation (if not already intubated) Oxygenation and ventilation Discontinue offending agents Administer dantrolene ↑ inspired O2 to 100%; increase ventilation rate/tidal volume Only known antidote Binds ryanodine receptors and blocks sarcoplasmic reticulum Ca release Monitor for hyperkalemia and check labs Initiate supportive care Place in ICU Continue maintenance dosing of dantrolene 48 hrs after last observed sign Counsel patient Avoid anesthesia with triggering agents Avoid excessive heat and humidity Inform family members Resources 1. 2. UpToDate, Malignant Hyperthermia: Clinical diagnosis and management of acute crisis, http://www.uptodate.com/contents/malignant-hyperthermia-clinicaldiagnosis-and-management-of-acutecrisis?source=search_result&search=malignant+hyperthermia&selectedT itle=1~72 Rosenberg H, Davis M, James D, Pollock N, Stowell K. Malignant hyperthermia. Orphanet J Rare Dis. 2007;2:21.