Prevention of hypothermia in children under combined epidural and general anesthesia: a comparison between upper‐ and lower‐body warming

Abstract

Children receiving combined epidural and general anesthesia may be at greater risk of hypothermia. Active warming should be undertaken to combat heat loss. With combined epidural and general anesthesia heat loss from the lower body may be greater than from the upper body because of shift of blood towards the vasodilated lower body. We assumed that application of the warming blanket to the lower body might provide better protection against hypothermia. To test this hypothesis, lower-body warming (LBW) was compared with upper-body warming (UBW) in a randomized comparative study. Children subjected to open urologic surgery under combined epidural and general anesthesia were randomly allocated to either UBW n = 38 or LBW n = 35 using a forced-air warming blanket. Core and peripheral skin temperatures were monitored. Temperature gradients between forearm and fingertip during LBW and between leg and toe during UBW were calculated. The warmer was set at 32 degrees C, room temperature was around 22 degrees C and fluids were infused at ambient room temperature. The changes in core temperature were comparable and parallel in both groups. Core temperature decreased significantly in each group at 1 h after induction compared with basal values. Temperature gradients at forearm-fingertip and at leg-toe were also comparable in both groups. Recovery was uneventful and no patient shivered in the recovery room. Lower body warming is as effective as UBW in prevention of hypothermia in children subjected to combined epidural and general anesthesia.