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Related to decompression illness: bends
, decompression sickness
, nitrogen narcosis
, Henry's law
, caisson sickness
Aeroembolism due to an excessively rapid ascent to the surface by a deep-sea diver. Synonym: bends
; caisson disease
; Synonym: diver's palsy
Affected patients should be transported to specialized treatment centers where recompression or hyperbaric chambers are available.
decompression illness the adverse effects of uncontrolled return to normal ambient pressure following exposure to high pressure when surfacing from a dive or, less commonly, exposure to rapid reduction in pressure in ascent from sea level in unpressurized aircraft. Symptoms range from pains in the joints, chest and back, weakness or sensory loss, to paralysis and loss of consciousness; severe neurological symptoms can be life-threatening. There are two main causes: (1) damage to the lungs by expansion of the gas in them if a diver does not freely exhale when surfacing. Gas can leak into the circulating blood (air embolus) or into the pleural cavity (pneumothorax); (2) release in the tissues (e.g. around joints or in the spinal cord) of bubbles of nitrogen that was dissolved in body fluids whilst at the higher pressure. Avoided or minimized by using computed tables to control speed of ascent and frequency of pauses, in relation to the duration and depth of the dive. All types of decompression illness require oxygen breathing as a first aid measure, and urgent treatment for all but the mildest by recompression to the initial higher pressure in a hyperbaric chamber, so that nitrogen is redissolved in body fluids, then more gradually released and exhaled as pressure is allowed to fall. See also diving.