Warming the premature infant in the delivery room: Quantification of the risk of hyperthermia

Abstract

Aim: The efficacy and safety of three polyethylene bags commonly used to prevent hypothermia in premature infants was assessed.

Methods: To simulate transfer from the delivery room to a secondary care unit, a thermally stable, bonneted mannequin (skin temperature: 34.4 °C) was placed in a climate chamber under different conditions: with a radiant warmer, with various polyethylene bags (open on one side, closed by a draw-string at the neck, or a "life support pouch" with several access points) or without a bag.

Results: With the radiant warmer turned on, the mean reduction in heat loss from the nude mannequin was 50.8 ± 1.7% (p < 0.0001, vs. warmer off). The mean reduction in heat loss (vs. no bag) was 55.0 ± 0.9% for the drawstring bag, 49.0 ± 2.2% for the standard bag (p = 0.0001), and 48.1 ± 0.7% for the life support pouch (p = 0.006). When a radiant warmer + polyethylene bag were used, heat stress (body temperature: 38 °C) and severe hyperthermia (40 °C) occurred after 11 and 34 min, respectively.

Conclusion: Caution must be taken when using a radiant warmer and polyethylene bag with a premature infant. Heat stress can occur in only 11 min. Continuous body temperature monitoring is therefore required.

Keywords: Adverse effect; Birth; Polyethylene bag; Radiant warmer; Temperature.