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  ↑ inspired O2 to 100%; increase ventilation rate/tidal volume  Discontinue offending agents  Administer dantrolene  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. UpToDate, Malignant Hyperthermia: Clinical diagnosis and management of acute crisis, diagnosis-and-management-of-acute- crisis?source=search_result&search=malignant+hyperthermia&selectedT itle=1~72 2. Rosenberg H, Davis M, James D, Pollock N, Stowell K. Malignant hyperthermia. Orphanet J Rare Dis. 2007;2:21.