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| '''Decompression sickness''' (also known as '''the bends''') is a condition experienced by anyone going from high pressure to lower pressure, and is typically experienced by ] who ascend too quickly from depths below 10 meters. | '''Decompression sickness''' (also known as '''the bends''') is a condition experienced by anyone going from high pressure to lower pressure, and is typically experienced by ] divers who ascend too quickly from depths below 10 meters. | ||
| When air under high pressure is breathed for any length of time, ] dissolves in the body fluids in higher than usual concentration. When moving to lower pressure, this causes the gas to come back out of solution, and form bubbles in the ]. The physiologist ] studied this problem in the early ], eventually devising the method of staged, gradual decompression, whereby the pressure on the diver is released slowly enough that the nitrogen comes gradually out of solution without forming bubbles. Repeated cases of decompression sickness can lead to brittle bones, and severe cases can lead to death. Severe cases of decompression sickness require treatment by recompression in a '']''. | When air under high pressure is breathed for any length of time, ] dissolves in the body fluids in higher than usual concentration. When moving to lower pressure, this causes the gas to come back out of solution, and form bubbles in the ]. The physiologist ] studied this problem in the early ], eventually devising the method of staged, gradual decompression, whereby the pressure on the diver is released slowly enough that the nitrogen comes gradually out of solution without forming bubbles. Repeated cases of decompression sickness can lead to brittle bones, and severe cases can lead to death. Severe cases of decompression sickness require treatment by recompression in a '']''. | ||
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| An alternative name is ''caisson disease''; this name comes from the 19th century, when large engineering excavations (]s, ]s) required the work to be done in "caissons" under pressure to keep water from flooding the excavations. This was a major factor for laborers working on the ], and incapacitated the project leader ]. | An alternative name is ''caisson disease''; this name comes from the 19th century, when large engineering excavations (]s, ]s) required the work to be done in "caissons" under pressure to keep water from flooding the excavations. This was a major factor for laborers working on the ], and incapacitated the project leader ]. | ||
| Because ] has a far lower solubility in water, decompression sickness can be avoided by breathing |
Because ] has a far lower solubility in water, nitrogen decompression sickness can be avoided by breathing other ]es such as ] and ] instead of air. Unfortunatley there is ]decompression sickness which takes longer exosure to helium before it becomes a problem. Helium is mainly used in ]es to reduce ]. | ||
| Other ill effects experienced by divers are ] and ]. | Other ill effects, due to ]es, experienced by divers are ] and ]. | ||
Revision as of 20:26, 9 February 2004
Decompression sickness (also known as the bends) is a condition experienced by anyone going from high pressure to lower pressure, and is typically experienced by SCUBA divers who ascend too quickly from depths below 10 meters.
When air under high pressure is breathed for any length of time, nitrogen dissolves in the body fluids in higher than usual concentration. When moving to lower pressure, this causes the gas to come back out of solution, and form bubbles in the blood. The physiologist J.S. Haldane studied this problem in the early 20th century, eventually devising the method of staged, gradual decompression, whereby the pressure on the diver is released slowly enough that the nitrogen comes gradually out of solution without forming bubbles. Repeated cases of decompression sickness can lead to brittle bones, and severe cases can lead to death. Severe cases of decompression sickness require treatment by recompression in a hyperbaric chamber.
An alternative name is caisson disease; this name comes from the 19th century, when large engineering excavations (bridges, tunnels) required the work to be done in "caissons" under pressure to keep water from flooding the excavations. This was a major factor for laborers working on the Brooklyn Bridge, and incapacitated the project leader Washington Roebling.
Because helium has a far lower solubility in water, nitrogen decompression sickness can be avoided by breathing other breathing gases such as heliox and trimix instead of air. Unfortunatley there is Heliumdecompression sickness which takes longer exosure to helium before it becomes a problem. Helium is mainly used in breathing gases to reduce nitrogen narcosis.
Other ill effects, due to breathing gases, experienced by divers are nitrogen narcosis and oxygen toxicity.