EFFECT OF HYPERBARIC-OXYGEN THERAPY ON SURVIVAL AFTER GLOBAL CEREBRAL-ISCHEMIA IN RATS

BACKGROUND Hyperbaric oxygenation (HBO) has been considered for many y ears for the treatment of severe brain ischemia. However, its efficacy has not been proven. The aim of this study was to shed light on this question. METHODS Acute global cerebral ischemia was induced in 18 rat s using the four-vessel occlusion model. Regional cerebral blood flow (CBF) was determined by laser-Doppler flowmetry using a flexible 1 mm fiberoptic probe. Two stainless steel screws were used to measure the spontaneous electrical activity from the contralateral hemisphere. Aft er ischemia monitored by laser-Doppler flowmetry and ECoG, the animals were divided into two groups: (1) control animals that breathed air a t atmospheric pressure and (2) rats exposed to HBO at three atmosphere s absolute pressure (ATA) for 1 hour. Survival time and rate were reco rded for both groups of animals for 14 days. RESULTS The survival rate in the study group was significantly higher (45%) than in the control group (0%). In the animals that did not survive the 14-day period, th ose exposed to HBO survived longer than the control animals (59.8 +/- 9.1 hour versus 17.9 +/- 2.7 hours, p < 0.05). CONCLUSION This investi gation demonstrates that HBO administered after global cerebral ischem ia can increase survival in a rat stroke model. (C) 1998 by Elsevier S cience Inc.