Cardiorespiratory response to free suspension simulating the situation between fall and rescue in a rock climbing accident

摘要

Many factors contribute to the risk of late death after successful rescue in a rock climbing accident. One factor may be hemodynamic and respiratory compromise by free suspension in a rope between fall and rescue. The risk probably results from using a chest harness alone or the combination of a chest harness and a sit harness. No trials on the acute cardiorespiratory response to free suspension in rock climbing have been reported so far. The effect of 3 min free suspension in a chest harness or in a sit harness on cardiopulmonary parameters was investigated in a randomized, cross-over trial in six healthy volunteers in a simulated rock climbing accident. Measurements were performed before and during the suspension at an altitude of 171 m. No statistical change in cardiopulmonary parameters was observed after free suspension in the sit harness. After free suspension in the chest harness, mean forced vital capacity decreased by 34.3% and mean forced expiratory volume decreased by 30.6%. No statistical change of arterial oxygen saturation occurred and mean end-tidal carbon dioxide increased by 11.5%. Mean heart rate decreased by 11.7%, mean systolic blood pressure decreased by 27.6%, mean diastolic blood pressure decreased by 13.1%, and mean cardiac output decreased by 36.4%. The p value for all reported changes was <0.05. We conclude that free suspension in a chest harness leads to a dramatic impairment of hemodynamics and respiration. This may contribute to the risk of a fatal outcome if rescue is not timely.