Flight Surgeon Module B Practice Test

Bubble formation in decompression sickness causes mechanical effects by physically disturbing tissues, compressing surrounding structures, and blocking small blood vessels so that tissue perfusion is reduced. The bubbles can tear or irritate tissues as they move, press on nerves and vessels causing pain and dysfunction, and obstruct microcirculation, leading to ischemia. This combination explains the characteristic pain, neurological signs, and organ or tissue injury seen in DCS. Endothelial damage is part of the cascade but not the whole picture; bubbles create direct mechanical disruption in addition to promoting inflammation. Increased metabolism and oxygen delivery would not be expected with bubbles; in fact, perfusion is typically compromised. Hyperbaric therapy treats DCS by shrinking and dissolving bubbles and improving oxygen delivery, not by accelerating clot formation.