suspect malignant hyperthermia in succinylcholine use and fever
- related: Pharmacology
- tags: #literature #icu #pharm
Malignant hyperthermia (MH) should be suspected in this patient because of the rapidly increasing temperatures associated with muscle rigidity of the face and jaw (trismus) after receiving succinylcholine (a depolarizing muscle relaxant). MH is a rare (1:10,000 and 1:250,000) autosomal dominant disorder that is life-threatening and is caused by exposure to volatile anesthetic agents and depolarizing muscle relaxants (such as succinylcholine). Patients with MH develop unexplained temperature increases, tachycardia, increases in end-tidal carbon dioxide, increases in minute ventilation, and muscle rigidity. Patients can also develop acidosis, hyperkalemia, and rhabdomyolysis owing to uncontrolled hypermetabolism. Once MH is suspected, steps should be taken immediately to reverse the reaction. These steps include the removal of the offending agent, external cooling measures, and IV dantrolene (choice D is correct.) The initial dose of dantrolene is 2 to 3 mg/kg. Additional doses of 1 mg/kg should be administered every 5 min until the end-tidal carbon dioxide is less than 45.11 mm Hg and core body temperature is less than 38.5 °C. The Malignant Hyperthermia Association of the United States also has a hotline available to assist in the diagnosis and management of MH, and all clinicians are encouraged to call this hotline with suspected cases (1-800-644-9737). Additional treatment measures include monitoring of potassium levels and treatment of hyperkalemia with calcium, insulin, and β2-agonists. Special care should be taken to avoid calcium channel blockers in patients suspected of having MH because they can lead to worsening hyperkalemia and cardiac arrest.1 23