A Comparison of Rewarming Methods in Mildly Hypothermic Individuals
Final rept. Aug-Sep 1989
NAVAL AIR DEVELOPMENT CENTER WARMINSTERPA
Pagination or Media Count:
The purpose of this study was to compare the rewarming effectiveness of a radio frequency coil 13.56MHz at a specific absorption rate SAR of 2.5 Wkg RF with warm water immersion 40 C WW and an insulated mummy-type rewarming sack TS. Four male subjects, ages 24-35, were immersed in 10 C water for up to 90 minutes or until their rectal temperatures TRE decreased to 35 C. Each subject had 3 trials in which they were immersed. After each immersion, rewarming was accomplished with either RF, WW, or TS, so that each subject was rewarmed once with each method. Comparisons of the three rewarming methods were based on the rate of increase of TRE during rewarming delta TRET, TRE 60 minutes after the start of rewarming TRE 60, the time interval measured from extraction from the water to the end of afterdrop deltat, and the magnitude of any observed Tre afterdrop deltaTre.WW had significantly greater deltaTREt and TRE60 than either RF or TS p0.03 and a smaller deltat than TS p0.05.TS had significantly greater delta TRE than either WW or RF p0.05. No significant differences in deltaTret, Tre60, or delta t were observed between TS and RF. The results of this study indicate that for mildly hypothermic individuals, rewarming with RF at a SAR of 2.5 Wkg is roughly equivalent to TS and less effective than WW.
- Medicine and Medical Research
- Escape, Rescue and Survival