Effect of pre-warmed intravenous fluids on perioperative hypothermia and shivering after ambulatory surgery under monitored anesthesia care.

Purpose: The aim of this study was to evaluate the effects of pre-warmed (approximately 41 °C) intravenous fluids (IV) on perioperative hypothermia and postoperative shivering in female patients undergoing short, ambulatory urological surgery under monitored anesthesia care (MAC).

Methods: Patients between the ages of 35 and 80 years were randomly assigned to either the pre-warmed (n = 27) or the room temperature (n = 26) group. According to group allocation, either pre-warmed IV fluids that had been stored in a warming cabinet for at least 8 h or room temperature IV fluids were administered intraoperatively up to approximately 600-700 ml, including a bolus infusion of 10 ml/kg within 20 min. Perioperative core temperatures at the tympanic membrane, postoperative shivering, subjective thermal comfort, and the use of forced-air warming interventions in the post-anesthesia care unit (PACU) were recorded.

Results: Mean core temperatures were significantly higher in the pre-warmed group than they were in the room temperature group after 10 ml/kg preload fluid was administered, at the end of the operation, and on admission to the PACU (p = 0.004, p = 0.02, and p = 0.008, respectively). The incidence of hypothermia (<36 °C) was significantly lower in the pre-warmed group (n = 4) than in the room temperature group (n = 11, p = 0.035) upon PACU admission. The postoperative shivering incidence was also significantly lower in the pre-warmed group (n = 2) than in the room temperature group (n = 8, p = 0.039).

Conclusions: Infusion of pre-warmed IV fluid improved the postoperative recovery profile by decreasing hypothermia and shivering in female patients undergoing short, ambulatory urological surgery under MAC.