Crit Care Med 1992 Nov;20(11):1588-94 (ISSN:
Takahashi M; Iwatsuki N; Ono K; Tajima T; Akama M;
Department of Anesthesiology, Tohoku University School of
Medicine, Sendai, Japan.
BACKGROUND AND METHODS:
Although hyperbaric oxygen therapy is
clinically used for the treatment of several types of ischemic brain
injury, few basic animal studies are available that provide a
rationale for this therapy for complete global brain ischemia.
Therefore, we investigated the effect of hyperbaric oxygen therapy
on neurologic recovery after 15-min complete global cerebral
ischemia in a canine model. Complete global ischemia was induced in
19 dogs by occlusion of the ascending aorta and the caval veins.
Nine dogs were randomized to treatment with hyperbaric oxygenation
(3 atmospheres absolute, 100% oxygen for 1 hr) at 3, 24, and 29 hrs
after ischemia under spontaneous respiration, while the other ten
dogs served as the control group without hyperbaric oxygen therapy
(group C). Neurologic recovery was evaluated based on the
electroencephalogram (EEG) activity score (1 = normal; 5 =
isoelectric) and the neurologic recovery score (100 = normal; 0 =
brain death) over a 14-day postischemic period.
The survival rates were 3/10 (30%) in the
control group vs. 7/9 (78%) in the group treated with hyperbaric
oxygen (p < .05). Over the 14-day postischemic period, the best
(lowest) EEG scores of each dog were significantly (1.7 +/- 0.2 vs.
2.9 +/- 0.3; mean +/- SE, p < .01) lower in the hyperbaric
oxygen-treated group. The best neurologic recovery scores of each
dog were significantly (69 +/- 6 vs. 48 +/- 5; mean +/- SE, p <
.05) higher in the treated animals. The number of dogs that
recovered to a neurologic recovery score of > 65 (assessed as a
slight disability) were 1/10 in the control group and 6/9 in the
group treated with hyperbaric oxygen (p < .02).
Hyperbaric oxygen therapy performed in the
early postischemic period accelerated neurologic recovery and
improved the survival rate in dogs after 15-mins of complete global