Induction of Profound Hypothermia for Emergency Preservation and Resuscitation Allows Intact Survival After Cardiac Arrest Resulting From Prolonged Lethal Hemorrhage and Trauma in Dogs

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Induction of Profound Hypothermia for Emergency Preservation and Resuscitation Allows Intact Survival After Cardiac Arrest Resulting From Prolonged Lethal Hemorrhage and Trauma in Dogs

Xianren Wu, MD; Tomas Drabek, MD; Patrick M. Kochanek, MD; Jeremy Henchir, BS; S. William Stezoski; Jason Stezoski; Kristin Cochran, BS; Robert Garman, DVM; Samuel A. Tisherman, MD
From the Safar Center for Resuscitation Research (X.W., T.D., P.M.K., J.H., S.W.S., J.S., K.C., R.G., S.A.T.) and the Departments of Anesthesiology (X.W., T.D.), Critical Care Medicine (P.M.K., S.A.T.), and Surgery (S.A.T.), University of Pittsburgh, Pittsburgh, Pa, and Consultants in Veterinary Pathology, Inc (R.G.), Murrysville, Pa.

Correspondence to Samuel A. Tisherman, MD, Safar Center for Resuscitation Research, 3434 Fifth Ave, Pittsburgh, PA 15260. E-mail tishermansa@ccm.upmc.edu

Received September 15, 2005; revision received February 14, 2006; accepted February 21, 2006.

Background— Induction of profound hypothermia for emergency preservation and resuscitation (EPR) of trauma victims who experience exsanguination cardiac arrest may allow survival from otherwise-lethal injuries. Previously, we achieved intact survival of dogs from 2 hours of EPR after rapid hemorrhage. We tested the hypothesis that EPR would achieve good outcome if prolonged hemorrhage preceded cardiac arrest.

Methods and Results— Two minutes after cardiac arrest from prolonged hemorrhage and splenic transection, dogs were randomized into 3 groups (n=7 each): (1) the cardiopulmonary resuscitation (CPR) group, resuscitated with conventional CPR, and the (2) EPR-I and (3) EPR-II groups, both of which received 20 L of a 2°C saline aortic flush to achieve a brain temperature of 10°C to 15°C. CPR or EPR lasted 60 minutes and was followed in all groups by a 2-hour resuscitation by cardiopulmonary bypass. Splenectomy was then performed. The CPR dogs were maintained at 38.0°C. In the EPR groups, mild hypothermia (34°C) was maintained for either 12 (EPR-I) or 36 (EPR-II) hours. Function and brain histology were evaluated 60 hours after rewarming in all dogs. Cardiac arrest occurred after 124±16 minutes of hemorrhage. In the CPR group, spontaneous circulation could not be restored without cardiopulmonary bypass; none survived. Twelve of 14 EPR dogs survived. Compared with the EPR-I group, the EPR-II group had better overall performance, final neurological deficit scores, and histological damage scores.

Conclusions— EPR is superior to conventional CPR in facilitating normal recovery after cardiac arrest from trauma and prolonged hemorrhage. Prolonged mild hypothermia after EPR was critical for achieving intact neurological outcomes.

Copyright © 2006 American Heart Association, Inc. All rights reserved. Unauthorized use prohibited.