Influence du niveau d'humidité de l'air sur le sommeil du nouveau-né en incubateur

Evaporative water losses am very important during the first weeks after birth m premature newborns. Humidity levels recommended in the literature are loca ted between 65 and 90% of relative humidity In most of the commercialised incubators, humidity is regulated in relative humidity although the evaporative water losses are inversely proportional to the gradient of water vapour partial pressure between the skin and the environment in our study, in order to pease physiological effects of humidity. we have used an active humidification system, controlling the water vapour partial pressure. By using our servocontrolled skm derivative heating device., the incubator air temperature level is spectfic to neonate is thermal needs ehowing to maintain body temperature constant independently of humidity level. With this system we have tested the effects of humidity level on sleep, heart rate and respiratory frequency m 9 neonates without inducing modifications of their thermal balance. A high humidity level of 4000 Pa (80% at 32%C) did not induce any disruption of sleep or cardiac and respiratory frequencies if thermal equilibrium of the neonate is maintained. This is observed when an inciease of the humidity level is accompanied by a decrease of incubator air temperature of 0.35 °C·kPa⁻¹.