Treatment of Acute Hyperthermia Crises

Early recognition is vital for the successful treatment of malignant hyperthermia. To this end routine monitoring of all patients undergoing anaesthesia must include: heart rate, blood pressure (preferably by electronic blood pressure cuff or direct arterial line), electrocardiogram, tidal volume, airway pressure, respiratory rate, end tidal carbon dioxide analysis, pulse oximeter, airway oxygen monitor, and body temperature. Once malignant hyperthermia is suspected, even remotely, therapy for this condition must be begun immediately. Appropriate treatment for malignant hyperthermia includes: stop all triggering agents instantly; infuse dantrolene 1.0 mg/kg/minute until temperature, muscle tone and heart decline into the normal range, change to a “clean” gas machine which has not previously been contaminated with lipid soluble potent inhalational agents; hyperventilate the patient with 100% oxygen; correct the metabolic acidosis with sodium bicarbonate; lower an early elevated serum potassium with a mixture of regular insulin in 50% glucose and raise a later low serum potassium with infusions of potassium chloride; prevent acute renal failure by administering furosemide and mannitol; and if the temperature is significantly elevated cool the patient by surface cooling, cold intravenous solutions and lavage of stomach, bladder, rectum and peritoneal and thoracic cavities.