Malignant Hyperthermia - 7

Prevention if possible: Management of an intraoperative episode of MH
  • discontinue triggers and
  • hyperventilate with 100% O2 and
  • call for help
  • mix and administer
    dantrolene (Dantrium) 3 mg/kg IV, then 1 mg/kg IV Q10 minutes to effect (resolution of acidosis) and continue for 24 to 72 hours. Dantrolene should be dissolved in sterile water (60 ml water plus 20 mg dantrolene - takes 5-10 minutes to dissolve). Each vial of Dantrium also contains 3 Gm mannitol. Dantrolene has a T1/2 of approximately 6 to 9 hours. It causes no acute serious toxicity other than muscle weakness, although chronic use for months may result in hepatotoxicity. (Dantrolene has a nonspecific, nondiagnostic antipyretic effect.)
  • cool the patient if necessary
    • plastic sheet filled with ice water
    • iced normal saline in body orifices, cavities and IV
  • consider: A-line, CVP line, Foley, PAC
  • consider: blood for CPK, K, lactate, blood gases
  • arrhythmias:
    • treat hyperkalemia
    • treat acidosis
    • procainamide 15 mg/kg IV slow over 10 minutes
    • lidocaine OK
    • NOT calcium channel blockers (verapamil + dantrolene has been reported to cause severe hyperkalemia and myocardial depression) (Durbin and Saltzman).
  • consider: sodium bicarbonate, furosemide, insulin + glucose
  • consider: call MH Hotline: 1-800-MH-HYPER (1-800-644-9737) (outside U.S. call: 0011-315-428-7924)
Postoperative management

Greg Gordon MD