OXYGEN DECOMPRESSION FOLLOWING AIR DIVES FOR USE IN HYPERBARIC OXYGEN THERAPY,

Two decompression schedules with use of oxygen were tested to provide for 3 and 4 hour air exposures at 3 atmospheres absolute pressure required for use in hyperbaric oxygen treatment. Schedules for such long exposures have not been available previously to permit use of oxygen breathing that decompression time be shortened. Six subjects were exposed to air breathing in a dry pressure chamber at 70 feet equivalent depth in sea water for periods of 180 and 240 minutes, respectively. Decompression was carried out with oxygen breathing at 30, 20, and 10 foot stops. All six subjects exposed for 180 minutes were symptom-free following decompression. Of six subjects exposed for 240 minutes, one subject developed transient vertigo one hour post dive, which resolved promptly with oxygen breathing at a depth of 60 feet. Greater than average susceptibility to decompression sickness from such prolonged exposures in this subject is considered to be a severe test of adequacy for this schedule. Thus, the schedules tested should provide efficient decompression for these prolonged exposures with minimal risk of symptoms of decompression sickness. No manifestations of oxygen toxicity appeared during the oxygen decompression periods. Author