Initial respiratory support with cold, dry gas versus heated humidified gas and admission temperature of preterm infants.

OBJECTIVE: To assess whether the addition of heated humidified gas (HHG) at delivery and until neonatal unit arrival improved admission temperatures of preterm infants. STUDY DESIGN: This multicenter, randomized controlled trial was performed in New Zealand and The Netherlands. Infants <32 weeks' gestation who required respiratory support after delivery were randomized to either cold, dry gas or HHG from birth. Standard measures to prevent hypothermia included heated delivery rooms, the use of radiant warmers, body wrap, and head covering. The primary outcome was axillary temperature in the normothermic (36.5-37.5°C) range on admission to a neonatal intensive care unit. Secondary outcomes were measures of respiratory support and neonatal morbidities. The effect of humidification was analyzed by the use of logistic regression. RESULTS: Of 203 randomized infants, 100 received HHG (humidifier set to 37°C) and 103 received cold, dry gas. In the HHG group, 69 (69%) were normothermic compared with 57 (55%) in the cold, dry gas group (unadjusted OR 1.8, 95% CI 1.01-3.19). A greater number of infants <28 weeks were normothermic on admission in the HHG group (24/35; ie, 69%) compared with the cold, dry gas group (16/38; ie, 42%; P = .03). In addition, 2 (2%) infants in the HHG group had admission temperatures <35.5°C compared with 12 (12%) in the cold, dry gas group (P = .007). Respiratory and short-term outcomes were not different. CONCLUSION: Adding HHG during respiratory support in preterm infants from birth increased the incidence of normothermia at admission.

Humidified and heated air during stabilization at birth improves temperature in preterm infants.

OBJECTIVE: Neonatal resuscitation guidelines recommend techniques to minimize heat loss in the delivery room. The use of humidified and heated gas is standard of care for preterm infants who need respiratory support in the NICU, but international resuscitation guidelines do not stipulate use of this therapy during stabilization at birth. We aimed to investigate the effect of humidified and heated gas on admission temperature in preterm infants who require respiratory support at birth. METHODS: Two cohorts of very preterm infants born at < or = 32 weeks' gestational age in the Leiden University Medical Center were compared prospectively before (the "cold" cohort) and after (the "heated" cohort) introduction of the use of heated and humidified gas during respiratory support at birth (continuous positive airway pressure or intubation). The primary outcome was the infant's rectal temperature at admission in the NICU. RESULTS: There was a difference in the mean (SD) rectal temperature between the cold and heated cohorts (35.9 [0.6] vs 36.4 [0.6], respectively; P < .0001). Normothermia (36.5 degrees C-37.5 degrees C) occurred less often in the cold cohort than in the heated cohort (12% vs 43%; P < .0001). There was no difference in occurrence of mild hypothermia (36.0 degrees C-36.4 degrees C) between groups (33% vs 35%; not significant). Moderate hypothermia (<36.0 degrees C) occurred more often in the cold cohort (53% vs 19%; P < .001). CONCLUSIONS: The use of heated and humidified air during respiratory support in very preterm infants just after birth reduced the postnatal decrease in temperature. Heating and humidifying the gas during stabilization merits additional investigation.