Reduction in Ambient Pressure
Acute ascent to altitude can result in bubbles forming within
tissues as a result of local supersaturation of inert gas. Although symptoms of
decompression illness have been reported to occur after rapid ascent in aircraft
to just 2437 m,[258]
they usually occur only in
aircraft in which ascent exceeds 5000 to 6000 m.[259]
After scuba diving, exposure to lower altitudes (2400 m or less) within 12 to 24
hours can precipitate decompression illness.[260]
To reduce the risk of decompression illness, it is the practice of individuals planning
a rapid decompression to low ambient pressure (e.g., military pilots, astronauts)
to denitrogenate their tissues by prebreathing 100% O2
for periods ranging
from a few minutes to several hours, depending on the altitude of the planned exposure.
