Hamster Mortality from Rapid Decompression.

The incidence of decompression sickness was observed in anesthetized hamsters subjected to rapid decompression from dives on compressed air to depths of 7 to 14.3 atmospheres absolute ATA. Appearance of bubbles in large arteries and veins was monitored with a dissecting microscope set up to observe the exposed vessels through a chamber window. No systemic symptoms accompanied the appearance of occasional bubbles in the large veins, but respiratory distress always occurred coincident with the appearance of bubbles in large arteries, or a shower of bubbles in large veins. The incidence of fatal decompression sickness as a function of pressure and bottom time was obtained by exposing groups of animals to different dive profiles varying from bottom times of 2 to 30 minutes, and pressures of 7.7 to 14.3 ATA. Analysis of the mortality data by the method of probit analysis indicated the presence of a slow tissue with a half time of 25.5 minutes and a spectrum of tissues with varying half times.