Full body forced air warming: commercial blanket vs air delivery beneath bed sheets

Single-use commercial forced air warming blankets serve only to distribute heated air from a blower. Standard bed sheets may be equally effective in delivering hot air within a lower body field and at lower cost.

Heated forced air at 38 degrees and 43 degrees was delivered within a simulated full-body field beneath standard hospital bed sheets or via a BAIR Model 315 commercial blanket. The air temperatures maintained within, as well as the caloric uptake of standard bodies containing 1000 ml water, were studied under standard simulated operating room conditions. Thermal input was provided by one Bair Hugger Model 500 Warming Unit and hospital acquisition cost for materials were calculated.

Air temperatures measured within the full body field at the three test sites were as great or greater using bed sheets (33.4-35.8 degrees) as with the commercial blanket (31.1-33.9 degrees), in spite of the 5 degrees cooler outlet temperature air settings @ 38 degrees vs 43 degrees, respectively (P = 0.003). Forced air delivered beneath bed sheets heated standardized thermal bodies twice as effectively as commercial blankets using identically warmed (38 degrees) forced air and heated as well as, or better, at the 38 degrees setting than did the commercial blanket at the 43 degrees setting. Calculated acquisition costs for sheets vs commercial blankets were $0.76 vs $18.00 US, respectively.

The simplicity, efficacy and economy of containing 38 degrees warm air beneath bed-sheets offer several advantages over commercial blankets and warrant further study.