Anesthesia & Analgesia, Vol 82, 803-809, Copyright © 1996 by International Anesthesia Research Society

GENERAL ARTICLES

Prior hypothermia attenuates malignant hyperthermia in susceptible swine

PA Iaizzo, CH Kehler, RJ Carr, DI Sessler and KG Belani
Department of Anesthesiology, University of Minnesota, Minneapolis, USA.

This study was designed to determine the extent by which mild or moderate hyperthermia attenuates the triggering of malignant hypothermia (MH) induced by the combined administration of halothane and succinylcholine. Sixteen susceptible swine were initially anesthetized with nontriggering drugs and then either kept normothermic (approximately equal to 38 degrees C, n = 6) or cooled to induce mild (approximately equal to 35 degrees C, n = 6), or moderate (approximately equal to 33 degrees C, n = 4) hypothermia. Next, after a 30-min control period, the normothermic and mildly hypothermic animals were administered 1 minimum alveolar anesthetic concentration (MAC) halothane followed by a bolus dose of succinylcholine (2 mg/kg). Within 10 min all normothermic animals developed fulminant MH, whereas the onset of MH was slowed or was absent in the mildly hypothermic group. To test whether moderate hypothermia could more effectively minimize the signs of a MH episode, this group of animals was exposed to 1.5 MAC halothane followed 10 min later by a 3-mg/kg bolus of succinylcholine. MH was not induced and anesthesia was then changed to nontriggering drugs (ketamine and pancuronium). The animals were then aggressively rewarmed to 38 degrees C: a slight increase in the ETCO2 was detected, but MH episodes did not spontaneously occur. Subsequently, the readministration of halothane and succinylcholine rapidly provoked fulminant MH. We concluded that the induction of mild hypothermia impairs triggering and reduces the progression of MH induced by the combined administration of halothane and succinylcholine, whereas moderate hypothermia was completely protective and thus could be considered for prophylaxis.

This article has been cited by other articles:

				A. A. Hannenberg and D. I. Sessler Improving Perioperative Temperature Management Anesth. Analg., November 1, 2008; 107(5): 1454 - 1457. [Full Text] [PDF]

				R. R. Johi, R. Mills, P. J. Halsall, and P. M. Hopkins Anaesthetic management of coronary artery bypass grafting in a patient with central core disease and susceptibility to malignant hyperthermia on statin therapy Br. J. Anaesth., November 1, 2003; 91(5): 744 - 747. [Abstract] [Full Text] [PDF]

				B. A. Claxton, M. H. Cross, and P. M. Hopkins No response to trigger agents in a malignant hyperthermia-susceptible patient Br. J. Anaesth., June 1, 2002; 88(6): 870 - 873. [Abstract] [Full Text] [PDF]

				D. I. Sessler Temperature Monitoring and Management During Neuraxial Anesthesia Anesth. Analg., February 1, 1999; 88(2): 243 - 243. [Full Text] [PDF]

				D. I. Sessler Mild Perioperative Hypothermia N. Engl. J. Med., June 12, 1997; 336(24): 1730 - 1737. [Full Text] [PDF]

Anesthesia & Analgesia® is published for the International Anesthesia Research Society® by Lippincott Williams & Wilkins with the assistance of Stanford University Libraries' HighWire Press®. Copyright 2006 by the International Anesthesia Research Society. Online ISSN: 1526-7598   Print ISSN: 0003-2999