Published Online
on August 19, 2004

A more recent version of this article appeared on October 1, 2004

This Article Full Text (PDF) All Versions of this Article: 35/10/2331    most recent 01.STR.0000141161.63181.f1v1 Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Zweifler, R. M. Articles by Parnell, M. Search for Related Content PubMed PubMed Citation Articles by Zweifler, R. M. Articles by Parnell, M. Pubmed/NCBI databases Compound via MeSH Substance via MeSH Hazardous Substances DB MAGNESIUM COMPOUNDS MAGNESIUM SULFATE MEPERIDINE Related Collections Emergency treatment of Stroke Other Stroke Treatment - Medical

Submitted on April 8, 2004
Revised on June 5, 2004
Accepted on July 7, 2004

Magnesium Sulfate Increases the Rate of Hypothermia Via Surface Cooling and Improves Comfort

Richard M. Zweifler MD^*; Marc E. Voorhees PhD; M. Asim Mahmood MD; and Mel Parnell RN, BSN

From the University of South Alabama Stroke Center (R.M.Z., M.A.M., M.P.), Mobile, Ala; and Medivance, Inc. (M.E.V.), Louisville, Colo.

^* To whom correspondence should be addressed. E-mail: rzweifle{at}usouthal.edu.

Background and Purpose--Therapeutic hypothermia shows promise as a treatment for acute stroke. Surface cooling techniques are being developed but, although noninvasive, they typically achieve slower cooling rates than endovascular methods. We assessed the hypothesis that the addition of intravenous MgSO₄ to an antishivering pharmacological regimen increases the cooling rate when using a surface cooling technique.

Methods--Twenty-two healthy volunteers were studied. Hypothermia was induced using a surface technique with a target tympanic temperature (Ttym) of 34.5°C (target range 34 to 35°C). Subjects received 1 of the following pharmacological regimens: (1) meperidine monotherapy (n=5); (2) meperidine plus buspirone, 30 to 60 mg PO administered at the time of initiation of cooling (n=4); (3) meperidine and ondansetron, 8 to 16 mg IV administered as an 8 mg bolus at the time of initiation of cooling with an optional second dose after 4 hours as needed for nausea (n=5); or (4) meperidine, ondansetron, and MgSO₄, 4 to 6 g IV bolus followed by 1 to 3 g per hour infusion (n=8). Thermal comfort was evaluated with a 100-mm-long visual analog scale.

Results--More subjects who received MgSO₄ were vasodilated during hypothermia induction (7 of 8 [88%] versus 4 of 14 [29%]; P=0.024). MgSO₄ (coefficient -17.265; P=0.039), weight (1.838, 0.001), and the initial 2-hour meperidine dose (0.726, 0.003) were found to significantly impact the time to achieve Ttym of 35°C. Subjects who received MgSO₄ had significantly higher mean comfort scores than those who did not (48±15 versus 38±12; P<0.001).

Conclusions--Administration of intravenous MgSO₄ increases the cooling rate and comfort when using a surface cooling technique.

Key words: hypothermia • magnesium sulfate • neuroprotection • stroke

This article has been cited by other articles:

				D. I. Sessler Defeating Normal Thermoregulatory Defenses: Induction of Therapeutic Hypothermia Stroke, November 1, 2009; 40(11): e614 - e621. [Abstract] [Full Text] [PDF]

				B. P. Meloni, K. Campbell, H. Zhu, and N. W. Knuckey In Search of Clinical Neuroprotection After Brain Ischemia: The Case for Mild Hypothermia (35{degrees}C) and Magnesium Stroke, June 1, 2009; 40(6): 2236 - 2240. [Abstract] [Full Text] [PDF]

				R. W. Neumar, J. P. Nolan, C. Adrie, M. Aibiki, R. A. Berg, B. W. Bottiger, C. Callaway, R. S.B. Clark, R. G. Geocadin, E. C. Jauch, et al. Post-Cardiac Arrest Syndrome: Epidemiology, Pathophysiology, Treatment, and Prognostication A Consensus Statement From the International Liaison Committee on Resuscitation (American Heart Association, Australian and New Zealand Council on Resuscitation, European Resuscitation Council, Heart and Stroke Foundation of Canada, InterAmerican Heart Foundation, Resuscitation Council of Asia, and the Resuscitation Council of Southern Africa); the American Heart Association Emergency Cardiovascular Care Committee; the Council on Cardiovascular Surgery and Anesthesia; the Council on Cardiopulmonary, Perioperative, and Critical Care; the Council on Clinical Cardiology; and the Stroke Council Circulation, December 2, 2008; 118(23): 2452 - 2483. [Full Text] [PDF]

				A. Wadhwa, P. Sengupta, J. Durrani, O. Akca, R. Lenhardt, D. I. Sessler, and A. G. Doufas Magnesium sulphate only slightly reduces the shivering threshold in humans Br. J. Anaesth., June 1, 2005; 94(6): 756 - 762. [Abstract] [Full Text] [PDF]