Emergency preservation and delayed resuscitation allows normal recovery after exsanguination cardiac arrest in rats: a feasibility trial.
OBJECTIVE
Emergency preservation and resuscitation (EPR) comprise a novel approach for resuscitation of exsanguination cardiac arrest victims. EPR uses a cold aortic flush to induce deep hypothermic preservation, followed by resuscitation with cardiopulmonary bypass. Development of a rat EPR model would enable study of the molecular mechanisms of neuronal injury and the screening of novel agents for emergency preservation.


METHODS
A prospective, randomized study.


METHODS
University research facility.


METHODS
Adult male Sprague-Dawley rats.


METHODS
Isoflurane-anesthetized rats were subjected to lethal hemorrhage (12.5 mL for 5 mins), followed by KCl-induced cardiac arrest and 1 min of no flow. Three groups (n=6) were studied: hypothermic EPR (H-EPR; 0 degrees C flush; target temperature, 15 degrees C); normothermic EPR (N-EPR; 38 degrees C flush); and controls. After 20 mins of H-EPR or N-EPR, resuscitation was initiated with cardiopulmonary bypass for 60 mins and mechanical ventilation. Controls were subjected to complete experimental preparation and anesthesia without cardiac arrest, followed by 60 mins of cardiopulmonary bypass and mechanical ventilation. Surviving rats were extubated 2 hrs later. Survival, Overall Performance Category (1, normal; 5, death), Neurologic Deficit Score, Histologic Damage Score, and biochemistry were assessed in survivors on day 7.


RESULTS
All rats in H-EPR and control groups survived, whereas none of the rats in the N-EPR group had restoration of spontaneous circulation. All rats in the H-EPR and control groups achieved Overall Performance Category 1, normal Neurologic Damage Score, and normal or near normal Histologic Damage Score and biochemical markers of organ injury.


CONCLUSIONS
We have established an EPR model in rats showing no neurologic injury, despite an exsanguination cardiac arrest, followed by 20 mins of EPR using miniaturized cardiopulmonary bypass. Establishment of this model should facilitate application of molecular tools to study the effects of hypothermic preservation and reperfusion and to screen novel pharmacologic adjuncts.
Drabek
Tomas
T
Safar Center for Resuscitation Research, and the Department of Anesthesiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260, USA.
Stezoski
Jason
J
Garman
Robert H
RH
Wu
Xianren
X
Tisherman
Samuel A
SA
Stezoski
S William
SW
Fisk
Jesse A
JA
Jenkins
Larry
L
Kochanek
Patrick M
PM
D000818:Animals; D002315:Cardiopulmonary Bypass; D050792:Circulatory Arrest, Deep Hypothermia Induced; D005240:Feasibility Studies; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D012151:Resuscitation; D013997:Time Factors