Introduction: Hypothermia may improve outcome after global cerebral ischemia, but the therapeutic window for postischemic hypothermia in animal models is relatively brief (15-60 minutes). Total body cooling (TBC) may reduce brain temperature slowly and may cause deleterious side effects, '"rMing decreased cardiac output We recently reported the feasibility of selective brain cooling (SBC) in piglets after cardiac arrest (1). In this study, we compared SBC and TBC after cardiac arrest and measured regional brain temperatures and hemodynamics. Methods: Piglets (4-Skg) were anesthetized (pentobarbital), mechanically ventilates and vascular catheters were inserted. Rectal, esophageal and 6 regional brain temperatures were monitored continuously. Animals underwent S mi of cardiac arrest (ventricular fibrillation), 6 min of CPR and defibrillatioa, and received either TBC (n-2) or SBC (n-3) beginning during CPR and continuing far 2 hours of reperrasion (R). Control animals were kept nonnothermic (NT, n=5). Vascular pressures, cardiac output (CO) and heart rate (HR) were measured at fratr'inf. during CPR and at 15, 30,45,60,90 and 120 min. R. Between group variables were analyzed with one-way ANOVA with Bonferroni's correction fer multiple comparisons. Significance was set at p < 0.05. Results: After 15R, mean brain temperatures were 35.u0.yC and 35.5±0 6°C in TBC and SBC nimai respectively (p-NS). Variability ni regional brain temperature, as measured by standard deviation across braia regions, was 0.2 to 0.4 in NT and TBC minMfr. but 0.6-1.4 in SBC 1% Vascular pieuures did not differ between group. CO was higher at 30R and 60R in SBC animals and HR was lower in TBC animals at 15R, 30R and 45R. CoachisMNu: SBC and TBC both lower brain temperature rapidly enough to confer hypothermie protection after but surface çppliqg PH greater variability in regional brain temperature. After resuscitation, CO and HR are higher during SBC.
|Original language||English (US)|
|Journal||Critical care medicine|
|Issue number||1 SUPPL.|
|State||Published - Dec 1 1998|
ASJC Scopus subject areas
- Critical Care and Intensive Care Medicine