Animacion Suspendida

The Journal of TRAUMA Injury, Infection, and Critical Care

Suspended Animation Can Allow Survival without Brain Damage after Traumatic Exsanguination Cardiac Arrest of 60 Minutes in Dogs
Ala Nozari, MD, PhD, Peter Safar, MD, FCCM, Xianren Wu, MD, William S. Stezoski, Jeremy Henchir, BS, Patrick Kochanek, MD, Miroslav Klain, MD, Ann Radovsky, DVM, PhD, and Samuel A. Tisherman, MD, FACS, FCCMBackground: We have previously shown in dogs that exsanguination cardiac arrest of up to 120 minutes without trauma under profound hypothermia induced by aortic flush (suspended animation) can be survived without neurologic deficit. In the present study, the effects of major trauma (laparotomy, thoracotomy) are explored. This study is designed to better mimic the clinical scenario of anexsanguinating trauma victim, for whom suspended animation may buy time for resuscitative surgery and delayed resuscitation. Methods: Fourteen dogs were exsanguinated over 5 minutes to cardiac arrest. Flush of saline at 2°C into the femoral artery was initiated at 2 minutes of cardiac arrest and continued until a tympanic
temperature of 10°C was achieved. The dogs were then randomized into a control groupwithout trauma (n 6) or a trauma group (n 8) that underwent a laparotomy and isolation of the spleen before hemorrhage and then, at the start of cardiac arrest, spleen transection and left thoracotomy. During cardiac arrest, splenectomy was performed. After 60 minutes of no-flow cardiac arrest, reperfusion with cardiopulmonary bypass was followed by intensive care to 72 hours. Results: All 14 dogssurvived to 72 hours with histologically normal brains. All control dogs were functionally neurologically intact. Four of eight trauma dogs were also functionally normal. Four had neurologic deficits, although three required prolonged mechanical ventilation because of airway edema and evidence of multiple organ failure. Blood loss from the chest and abdomen was variable and was associated withpoor functional outcomes. Conclusion: Rapid induction of profound hypothermic suspended animation (tympanic temperature, 10°C) can enable survival without brain damage after exsanguination cardiac arrest of 60 minutes even in the presence of trauma, although prolonged intensive care may be required. This technique may allow survival of exsanguinated trauma victims, who now have almost no chance ofsurvival. Key Words: Suspended animation, Brain damage, Traumatic exsanguination.
J Trauma. 2004;57:1266 –1275.

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espite advances in resuscitation techniques and in surgical management of trauma victims, survival rates remain extremely low in trauma patients who exsanguinate to cardiac arrest.1,2 Emergency department thoracotomy to treat cardiac tamponade, control intrathoracic hemorrhage,perform open-chest cardiac massage, and cross-clamp the aorta to optimize cerebral and myocardial perfusion and decrease intra-abdominal hemorrhage is often performed, but the surgical team’s race against the clock to achieve hemo-

Submitted for publication July 28, 2003. Accepted for publication January 21, 2004. Copyright © 2004 by Lippincott Williams & Wilkins, Inc. From the Safar Center forResuscitation Research (A.N., P.S., X.W., M.K., S.A.T., P.K.) and the Departments of Anesthesiology (A.N., P.S., X.W., M.K.), Surgery (S.A.T.), Pediatrics (P.K.), and Critical Care Medicine (P.K., S.A.T.), University of Pittsburgh, Pittsburgh, Pennsylvania. Supported by U.S. Army Medical Research and Materiel Command/ Telemedicine and Advanced Technology Research Center grant DAMD 17-01-2-0038 andthe Laerdal Foundation for Acute Medicine. Presented at the American Society of Anesthesiologists’ Annual Meeting, October 16, 2002, Orlando, Florida. Address for reprints: Samuel A. Tisherman, MD, FACS, FCCM, Safar Center for Resuscitation Research, University of Pittsburgh, 3434 Fifth Avenue, Pittsburgh, PA 15260; email: tishermansa@ccm.upmc.edu. DOI: 10.1097/01.TA.0000124268.24159.8B...