Warming intravenous fluids reduces perioperative hypothermia in women undergoing ambulatory gynecological surgery.
We evaluated whether warming i.v. fluids resulted in less hypothermia (core temperature < 35.5 degrees C) compared with room-temperature fluids. Thirty-eight adult outpatients undergoing elective gynecological surgery of > 30 min were randomized to two groups: fluid warming at 42 degrees C or control (room temperature fluids at approximately 21 degrees C). All patients received general anesthesia with isoflurane, tracheal intubation, standard operating room blankets and surgical drapes, and passive humidification of inspired gases. Tympanic membrane (core) temperatures were measured at baseline and at 15-min intervals after induction. The incidence of shivering and postoperative requirement for meperidine and/or radiant heat were evaluated. Core temperatures were lower in the control compared with the warm fluid group at the end of surgery (35.6 +/- 0.1 degrees C vs 36.2 +/- 0.1 degrees C; P < 0.05). More patients had final core temperature < 35.5 degrees C in the control compared with the warm fluid group (35% vs 0%; P < 0.05). There were no differences in time to discharge from the postanesthesia care unit or the incidence of shivering between the groups. We conclude that fluid warming, in conjunction with standard heat conservation measures, was effective in maintaining normothermia during outpatient gynecological surgery; however, there was no improvement in patient outcome. Women who received i.v. fluid at body temperature had significantly higher core temperatures during and after outpatient gynecological surgery compared with women who received i.v. fluids at the temperature of the operating room.