Design and Performance of Blanket Heat Shields for Neonates

Abstract

Several designs of plastic blanket heat shields are in use. This study was done to compare different designs for their efficiency in reducing heat loss. Four heat shield designs were tested by sequentially covering each of 14 infants (wt. 640-2,030 g) cared for under radiant warmers. The power consumption of the radiant warmers was measured as a surrogate for heat loss. All designs were tested for a total of 20 min on all infants. Results were calculated as percent change in power consumption from shield to shield. The most efficient design was further modified and evaluated in another group of 14 infants (wt. 700-1,180 g). The relative reductions in power consumption were: no shield (control) -0%, a plastic foil over the side rails: -17%, a single layer close to the infant but excluding the head: -34%, the same as double layer -37% and the most efficient one, a single layer covering the whole infant -42%. A modification of this design, tested in the second group of infants, reduced power consumption by 13% (95% CI -5.9/-19.7), (p less than 0.004) when compared to the single layer covering the whole infant. It was tucked under the connecting tubes to the ventilator. It also reduced the risk for displacement and allowed for the endotracheal tube to be suctioned without removing the blanket. Modifications of the design of heat shield blankets for infants resulted in significant increases in efficiency.