Efficacy of polyethylene plastic wrap for the prevention of hypothermia during immediate postnatal period in premature infants : a randomized controlled trial

Abstract

Objective: To assess the efficacy of occlusive body wrapping with polyethylene plastic bag to prevent hypothermia in premature infants during immediate postnatal period. Design: Randomized controlled trial Setting: King Chulalongkorn Memorial Hospital, Thai Red Cross Society Methods: Premature infant of 34 weeks gestation or less were randomized to study or control group. Study infants were placed in polyethylene plastic bags immediately after birth in delivery room, leaving only the head uncovered and were kept in plastic bags for 3 hours. Any resuscitation or treatment was done with the bags covering the bodies. Control infants were dried and resuscitated per standard protocol before transferred to nursery. All infants were stabilized under radiant warmers. Rectal temperature was taken on nursery admission and hourly thereafter for 3 hours by a digital thermometer. Results: Of 130 randomized infants, 122 completed the study (61 in each group). The infants in wrap group had lower incidence of hypothermia on admission (26.2 vs 50%, p=0.007, OR 0.36; 95%CI, 0.17 to 0.76) as well as hypothermia during the 3 hours study period (44.3 vs 70.5%, p=0.003; OR 0.33, 95%CI, 0.16 to 0.70). Wrapped infants also had higher rectal temperature on admission (36.7 ± 0.54 vs 36.3 ± 0.66 ºC, p= 0.002) and at 1 hour after admission (36.6 ± 0.46 vs 36.4 ± 0.46 ºC, p= 0.032). The effects of wrapping on prevention of hypothermia was still significant after adjustment for birth weight, small for date, low 1-minute Apgar score, and umbilical catheterization (adjusted OR 0.39, 95%CI, 0.17 to 0.87). Subgroup analysis showed significant higher admission rectal temperature and lower incidence of hypothermia on admission and throughout the study period in infants of less than 31 weeks’ gestation (difference in mean rectal temperature = 0.62 ºC, 95% CI, 0.18 to 1.05) but not in infants of 31 to 34 weeks’ gestation. Conclusion: Occlusive body wrapping with polyethylene plastic bag in delivery room is efficacious in the prevention of hypothermia in premature infants during immediate postnatal period.