PSYCHOPHYSIOLOGICAL REACTIONS IN HUMANS DURING AN OPEN SEA DIVE TO 500 M WITH A HYDROGEN-HELIUM-OXYGEN MIXTURE

Psychophysiological reactions in humans during an open sea dive to 500 m with a hydrogen-helium-oxygen mixture. J. Appl. Physiol. 76(3): 111 3-1118, 1994. - Six commercial divers were investigated for neurologic al and psychosensorimotor responses during an open sea dive to 500 m w ith a hydrogen-helium-oxygen mixture containing 49% hydrogen. Results showed only moderate neurological symptoms of high-pressure nervous sy ndrome, whereas the narcotic effect of hydrogen was detectable, as inv estigated by psychosensorimotor tests. Nevertheless, the divers succes sfully carried out the main purpose of the operational dive, which was to prove the feasability of such diving methods by connecting specifi c elements of an offshore oil installation. Finally, these data suppor t the hypothesis that hydrogen can alleviate some of the symptoms of t he high-pressure nervous syndrome and can constitute a useful gas for commercial diving, as it decreases the density of the breathing mixtur e and therefore improves the living conditions, work, and comfort of t he divers. Nevertheless, the present results underscore the relevance of research on individual susceptibility to pressure environment regar dless of the composition of the breathing mixture.