The influence of increased barometric pressure on man.―II

Abstract

Abstract In a previous communication, we gave reasons for thinking that decompression symptoms may be avoided by maintaining a steady rate of 20 minutes per atmosphere during this process. The actual time selected was purely empirical, being based on the statistics of Caisson Works, Diving Operations, and Laboratory Experiments. It is clear that a more scientific foundation would be obtained if we could determine (1) the rate at which the tissue fluids are saturated with nitrogen; (2) the rapidity with which dissolved gas escapes during decompression. The most direct method would be to analyse samples of arterial blood under various pressure conditions; but this is not, unfortunately, practicable in the case of man. Another way is the examination of venous samples under similar circumstances. This plan can be followed, and we hope to communicate some results in another paper, but the technic is difficult and still in need of improvement. A third line of research is the indirect determination of the tissue gases, and this will be discussed in the present communication.