Effect of high incubator humidity on hydration associated morbidity for very premature infants

Humidifying infant incubators facilitates heat retention, but entails an infection risk from microbial humidifier contamination. The Royal Victoria Hospital nursery was recently reequipped with steam humidity source incubators and converted to incubator humidification. An observational (before-after) study investigated the association between incubator humidification and hypernatremia and (secondarily) other hydration associated outcomes in very premature infants.Thirty-one incubator humidification and 60 non-humidification period infants were compared. Mean gestational age was 25.83 weeks for both groups. Mean highest serum sodium values were 143.5 (SD 9.4) and 152.9 (SD 4.9) mEq/l respectively (p < 0.001). Differences persisted after adjustment for confounding by age of placement in incubators, and in spite of fluid reduction in the D humidification period. Of infants with umbilical lines 2/16 and 33155 respectively attained serum potassium measurements over 6.9 mEq/l (p = .04). Overhydration outcomes did not differ, but power was limited and confounding was problematic for these analyses.In summary, incubator humidification is associated with decreased hypernatremia and hyperkalemia in very premature infants