Heat Loss Prevention for Preterm Infants in the Delivery Room

Abstract

OBJECTIVE:Preterm infants are prone to hypothermia immediately following birth. Among other factors, excessive evaporative heat loss and the relatively cool ambient temperature of the delivery room may be important contributors. Most infants <29 weeks gestation had temperatures <36.41C on admission to our neonatal unit (NICU). Therefore we conducted a randomized, controlled trial to evaluate the effect of placing these infants in polyurethane bags in the delivery room to prevent heat loss and reduce the occurrence of hypothermia on admission to the NICU. METHODS:After parental consent was obtained, infants expected to be <29 weeks gestation were randomized to intervention or control groups just prior to their birth. Infants randomized to the intervention group were placed in polyurethane bags up to their necks immediately after delivery before being dried. They were then resuscitated per NRP guidelines, covered with warm blankets, and transported to the NICU, where the bags were removed and rectal temperatures were recorded. Control infants were resuscitated, covered with warm blankets, and transported without being placed in polyurethane bags. Delivery room temperatures were recorded so this potentially confounding variable could be assessed. RESULTS:Intervention patients were less likely than control patients to have temperature < 36.41C on admission , 44 vs 70% ( p<0.01) and the intervention group had a higher mean admission temperature, 36.51C vs 36.01C ( p<0.003). This effect remained significant ( p<0.0001) when delivery room temperature was controlled in analysis. Warmer delivery room temperatures (Z261C) were associated with higher admission temperatures in both intervention and control infants, but only the subgroup of intervention patients born in warmer delivery rooms had a mean admission temperature >36.41C. CONCLUSIONS:Placing infants <29 weeks gestation in polyurethane bags in the delivery room reduced the occurrence of hypothermia and increased their NICU admission temperatures. Maintaining warmer delivery rooms helped but was insufficient in preventing hypothermia in most of these vulnerable patients without the adjunctive use of the polyurethane bags.

Heat loss prevention in neonates

“…Over two-thirds of ELBW infants are admitted to neonatal intensive care units (NICUs) with temperatures that would be considered hypothermic. 10 Mechanisms of preventing heat loss Mechanisms to prevent heat loss in newborn infants include the most basic manipulation of the environment to the most sophisticated and highly technical interventions. First and foremost, the general environmental temperature must be addressed.…”

“…Cold delivery rooms (delivery rooms maintained at a temperature <26 1C) have been associated with colder admission temperatures in the NICU for ELBW infants. 10 Raising delivery room temperature may be one of the most direct ways that hypothermia and cold stress can be addressed.…”

Heat Loss Prevention in the Delivery Room for Preterm Infants: A National Survey of Newborn Intensive Care Units

“…2 Despite World Health Organization 3 recommendations to keep the delivery room temperature at least 251C, it is common for extremely low birth weight (ELBW) infants to be exposed to cold environments in the delivery room after birth and through stabilization. In the past, we found delivery room temperatures to be as low as 18.91C, 4 despite attempts to keep delivery room temperatures at least 261C. Cold stress is more likely during the birth process and during stabilization in the delivery room because the infant is delivered from the warm intrauterine environment to the cold, drafty environment of the delivery room.…”

“…In three randomized controlled trials (RCT), 4,6,7 we have shown that polyethylene wrap or polyurethane bags prevented heat loss in preterm infants less than 29-weeks gestation in the delivery room. In all studies, the preterm infant was delivered and placed on the radiant warmer for resuscitation, then intervention group infants were immediately covered with polyethylene wrap or polyurethane bags from the neck down while still wet with amniotic fluid.…”

Improving neonatal unit admission temperatures in preterm babies: exothermic mattresses, polythene bags or a traditional approach?

“…This approach has been superseded by the technique of wrapping preterm babies in food or hospital standard polythene bags to prevent evaporative heat loss while permitting radiant warming. [9][10][11][12][13][14] Despite the relative success of wrapping babies in polythene bags, some are still hypothermic. In the HeLP study of babies <28 weeks wrapped in polythene bags, the mean rectal admission temperature was 36.5 1C (s.d., 0.8 1C).…”