Evaluation of the efficacy of a forced-air warmer (bair hugger) during spinal surgery in children

Abstract

To evaluate the efficacy of a forced-air warmer during spinal surgery for correction of scoliosis in children. Prospective randomized study (group allocation based on the availability of the warming device). Children's teaching hospital. 51 ASA physical status I and II children (mean age, 15 years; mean weight, 45 kg) scheduled for posterior spinal fusion with general anesthesia. Study group (warmed; n = 26)--legs covered with the forced-air warmer (Bair Hugger, Augustine Medical, Inc., Eden Prairie, MN) after installation of the patient in prone position--versus control group (n = 25)--400W heat lamp placed over the head during surgery as is usually done in our institution. Rectal temperature was taken every 15 minutes during surgery and during the first 2 hours in the recovery room. Time required for the wake-up test, time to extubation, and blood loss also were noted. Temperature profiles were very different in the 2 groups. In the control group, rectal temperature decreased during the first 180 minutes to a minimum of 34.8 degrees C +/- 0.6 degrees C, followed by a slow rewarming phase. In the warmed group, the lowest temperature (35.6 degrees C +/- 0.5 degrees C) was recorded 45 minutes after placement of the forced-air warmer, followed by an effective warming phase. At the end of surgery, temperature was significantly higher in the warmed group than in the control group (36.5 degrees C +/- 0.8 degrees C vs. 35.4 degrees C +/- 0.9 degrees C). However, time required for the wake-up test, time to extubation, and blood loss did not differ between groups. The forced-air warmer (Bair Hugger) is effective during spinal surgery, although only about 20% of body surface area can be covered.