Dantrolene with anesthesia

The pretreatment of MH-susceptible patients with oral or intravenous dantrolene prior to surgery in order to avoid a crisis is controversial. Most physicians do not recommend prophylactic pretreatment except in patients who have had a previously documented episode. However, if pretreatment is desired, it is recommended that therapy be begun with intravenous dantrolene in a dose of 2 mg/Kg just prior to induction of anesthesia. This prevents the uncertainty of predictive blood values associated with the use of the oral route. The adverse effects of intravenous dantrolene prophylaxis include phlebitis and tissue necrosis. Patients who receive prophylactic treatment with oral dantrolene often complain of incapacitation, gastrointestinal irritation, prolonged drowsiness, and clinically significant respiratory muscle weakness. 

A 28-year-old man, who developed malignant hyperthermia after anesthesia induced with isoflurane and maintained with sevoflurane, died 4 days later, despite cooling and intravenous dantrolene (49). 

Body temperature Malignant hyperthermia occurred 3 hours after the start of an operation for esophageal resection in an 82-year-old man after anesthesia induced with propofol and suxamethonium and maintained with sevoflurane [6 ]. Masseter spasm was not a feature. End-tidal CO2 rose to 55 mmHg and body temperature exceeded 39.0°C. The patient responded promptly to dantrolene. Reports of malignant hyperthermia in patients over the age of 80 years are unusual. Both suxamethonium and sevofiur-ane are potent triggers. 

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