Insensible water loss in extremely preterm infants cared for in incubators with 70% and 90% relative humidity.

OBJECTIVE

To determine the insensible water losses (IWL) in preterm infants cared for in incubators with 70% or 90% relative humidity (RH).

STUDY

DESIGN

This was a single center retrospective study of extremely preterm infants between 22- and 28-weeks gestational ages nursed in 70% and 90% RH. IWL was calculated using a formula that utilized infants' fluid intake, urine output and body weight changes. IWL between the two groups were compared using independent t-test. Multivariate linear regression was used to assess the effects of humidity on IWL after adjusting for confounding variables.

RESULTS

IWL was higher in infants nursed in 70% RH when compared with those nursed in 90% RH (47.7 ± 30.3 vs. 28.8 ± 39.6, p = 002). Multivariate linear regression analysis showed that RH has an independent effect on the insensible water loss.

CONCLUSION

Extremely preterm infants nursed in incubator with 70% RH have higher IWL than infants nursed in 90% RH.