Decompression sickness and flight-related factors.

Decompression sickness and flight-related factors.

• A. Decompression sickness is dehydration; risk increases with dry cabin air.
• B. Decompression sickness is infection caused by exposure to contaminated air.
• C. Decompression sickness is inert gas bubble formation during rapid decompression; risk increases with rapid altitude gain, long flight times, and recent diving.
• D. Decompression sickness is an allergic reaction to cabin pressure changes.

Answer: (C)

Decompression sickness comes from inert gas bubbles forming in the body as ambient pressure falls. In aviation terms, when a rapid decompression occurs or when a person ascends to altitude quickly, dissolved gases (mainly nitrogen) come out of solution and create bubbles in blood and tissues. The risk is highest for someone who has recently been diving, because nitrogen remains dissolved in tissues after a dive and can form bubbles more readily when pressure drops. Longer flight times also raise the chance of bubble formation or expansion because of prolonged exposure to lower effective pressures during ascent and cruising. This is why rapid altitude gain, extended flights, and a recent dive are the classic risk factors for decompression sickness. It’s not caused by dehydration per se, an infection, or an allergic reaction to cabin pressure changes, though dehydration can worsen symptoms.

Decompression sickness comes from inert gas bubbles forming in the body as ambient pressure falls. In aviation terms, when a rapid decompression occurs or when a person ascends to altitude quickly, dissolved gases (mainly nitrogen) come out of solution and create bubbles in blood and tissues. The risk is highest for someone who has recently been diving, because nitrogen remains dissolved in tissues after a dive and can form bubbles more readily when pressure drops. Longer flight times also raise the chance of bubble formation or expansion because of prolonged exposure to lower effective pressures during ascent and cruising. This is why rapid altitude gain, extended flights, and a recent dive are the classic risk factors for decompression sickness. It’s not caused by dehydration per se, an infection, or an allergic reaction to cabin pressure changes, though dehydration can worsen symptoms.