CHAPTER 46 Malignant Hyperthermia and Other Motor Diseases
3 Describe the cellular events, presentation, and metabolic abnormalities associated with malignant hyperthermia
4 How is malignant hyperthermia treated?
Notify the surgeon and operating-room personnel of the situation at hand and expedite conclusion of the procedure, even if it may require that surgery go unfinished.
Administer dantrolene, 2 mg/kg; repeat every 5 minutes to a total dosage of 10 mg/kg if needed. Dantrolene sodium inhibits calcium release via RyR1 antagonism.
Cool the patient, using interventions such as iced fluids and cooling blankets, but become less aggressive in reducing body temperature at about 38° C.
Promote urine output (2 ml/kg/hr), principally with aggressive fluid therapy, although mannitol and furosemide may also be required.
6 How is malignant hyperthermia susceptibility assessed in an individual with a positive family history or prior suggestive event?
7 What are the indications for muscle biopsy and halothane-caffeine contracture testing?
Definite indications: Suspicious clinical history for MH, family history of MH, prior episode of masseter muscle rigidity
Possible indications: Unexplained rhabdomyolysis during or after surgery, sudden cardiac arrest caused by hyperkalemia, exercise-induced hyperkalemia, moderate-to-mild masseter muscle rigidity with evidence of rhabdomyolysis