Loss of Consciousness During Parachute Jumps

Abstract

Parachute jumping belongs to extreme sports. Parachute jumps may result in hypobaria, hypoxia, hypothermia, overload, physical effort and stress. The case report presented in the paper concerns loss of consciousness during a parachute jump. A 37 year old, experienced jumper performed the CRW-2 task from 4000 m together with his instructor, immediately opening the parachute. At an altitude of 1000m, after finishing his acrobatic evolution, he lost of consciousness for 2,5 minutes. He landed in a tree, next recovered consciousness and safely went down. The results of medical examination were normal. The authors analyze a physiological mechanism underlying loss of consciousness, diagnosing slide hypoxia, physical effort and stress that caused hyperventilation and constriction of cerebral arteries. Interruption of physical effort caused the decreased venous return and cardiac output, critical decrease in cerebral blood flow and loss of consciousness. The jumper was diagnosed as fit for parachute jumping with limitation to 3000m and without excessive physical effort.