Evaluation of cutaneous insensible water loss during hyperbaric exposure in humans

Background: Water evaporation diminishes in high pressure environment, howe ver it is unknown whether insensible water dissipation from the human skin falls as a function of the increased environmental pressure. We designed th e present study to measure cutaneous insensible water loss at various press ures during exposure to a simulated saturation dive. Methods: Four healthy male volunteers were exposed to eight different pressures between 1 and 18. 4 atmospheres absolute (atm abs). Resting insensible water loss from the sk in was measured as change in the body weight and corrected for the weight o f the respiratory CO2 - O-2 gas exchange and the respiratory water dissipat ion. Results: We made an equation for the relationship between cutaneous in sensible water loss and environmental pressure as: w = 14.5.p(-0.48), where , w is cutaneous insensible water loss in g.m(-2).h(-1), and P is the envir onmental pressure in atm abs. The average cutaneous insensible water loss ( 15.3 g.m(-2).h(-1)) at normal atmosphere decreased (p < 0.01) to 4.2 g.m(-2 ).h(-1) (reduced by 73%) during a saturation dive to 18.4 atm abs. Conclusi on: The amount of insensible water loss estimated from the equation was com parable to that of reported observations.