Therapeutic effects of hyperbaric oxygenation on acute focal cerebral ischemia in rats.

The effects of hyperbaric oxygenation on acute focal cerebral ischemia in rats were investigated. All rats suffered 4-hour middle cerebral artery occlusion. Nontreated controls had a 27.9% +/- 5.5% infarct volume, and a left/right hemispheric volume ratio of 109% +/- 3%. Animals treated between 2.5 and 3.5 hours following occlusion had an 18.1% +/- 9.7% infarct volume (p less than 0.01), and a 105% +/- 3% left/right hemispheric volume ratio (p less than 0.001). In conclusion, at least until 4 hours following an ischemic insult, hyperbaric oxygenation reduces ischemic neuronal injury and brain edema following middle cerebral artery occlusion in rats treated between 2.5 and 3.5 hours following occlusion.