Hyperbaric oxygenation therapy enhances the protective effect of moderate hypothermia against forebrain ischemia in the gerbil hippocampus.
Moderate hypothermia may have a beneficial effect on the neurological outcome. However, ischemic deterioration such as brain swelling during rewarming has been reported as a notable complication after successful therapeutic cerebral hypothermia. In this study, we investigated the effects of hyperbaric oxygenation during rewarming. Forebrain ischemia was produced in 24 gerbils and sham ischemia in 8 animals. Then ischemia-treated animals were divided into 3 groups, whole-body moderate hypothermia (31 degrees C for 60 min) and hyperbaric oxygenation (HBO2) (2- atmosphere absolute for 60 min using 100% oxygen) during rewarming group (n = 8), moderate hypothermia without HBO2 group (n = 8), and sham treatment without hypothermia and without HBO2 group (n = 8). Both the hypothermia group (77.9 +/- 48.1 neurons per mm, mean +/- SD) and hypothermia + HBO2 group (127.6 +/- 29.7 neurons per mm,) showed significant preservation of CA1 pyramidal neurons in the hippocampus compared to that in the sham treatment group (6.4 +/- 2.7) (p < 0.01). Furthermore, the hypothermia + HBO2 group showed significantly greater preservation of CA1 pyramidal neurons than the hypothermia group (p < 0.05). These results suggest that HBO2 during rewarming preserves the protective effect of hypothermia against ischemic neuronal damage.
Wada
K
K
Department of Neurosurgery, Japan Defense Force Central Hospital, Setagaya, Tokyo, Japan.
Nishi
D
D
Kitamura
T
T
Ono
K
K
Takahara
T
T
Shirotani
T
T
Shimizu
A
A
D000818:Animals; D016923:Cell Death; D003131:Combined Modality Therapy; D005849:Gerbillinae; D006624:Hippocampus / Q000098:blood supply; D006931:Hyperbaric Oxygenation; D007036:Hypothermia, Induced; D007511:Ischemia / Q000517:prevention & control*; D008297:Male; D009474:Neurons / Q000473:pathology / Q000502:physiology*; D016548:Prosencephalon / Q000098:blood supply* / Q000473:pathology; D017694:Rewarming