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

Abstract

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). 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. 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). 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.