Effect of Oxygen at High Pressure (OHP) on Asphyxial Survival Time of Rats. ∗

Abstract

Summary

The effects of combining pressure oxygenation at 3 atmospheres with hypothermia (20°C) on asphyxial survival of rats following tracheal occlusion have been studied. Exposure to 100% oxygen at high pressure (OHP) without hypothermia increased survival times about 55-80% over those seen in animals breathing 100% oxygen at ATP. Oxygenation at 3 atmospheres combined with hypothermia at 20°C gave maximal prolongation of survival, although this was not significantly greater than seen with hypothermia alone. Addition of CO₂ to the inspired O₂ under pressure also afforded additional protection, even in absence of hypothermia. The action of OHP and hypothermia in increasing survival is additive rather than synergistic.