The effects of warming intravenous fluids on intraoperative hypothermia and postoperative shivering during prolonged abdominal surgery

Background: The infusion of several liters of crystalloid solution at room temperature may significantly contribute to intraoperative hypothermia because warming fluid to core temperature requires body heat. The aim of this study was to evaluate the effect of delivering warmed intravenous (IV) fluid to the patient on preventing intraoperative hypothermia. Methods: Intraoperative core and mean skin temperatures were measured during prolonged abdominal surgery in 18 patients randomly divided into two groups according to intraoperative IV fluid management. In 9 patients (control group) all IV fluids infused were at room temperature. In the other 9 patients (group receiving warmed fluids) all IV fluids were warmed using an active IV fluid tube-warming system. In all 18 patients a warming blanket covered the skin surface available for cutaneous warming. Intraoperative changes in total body heat content (kJ) were calculated from core and mean skin temperatures. Results: At the end of surgery, core temperature was 36.7+/-0.2 degrees C in the group receiving warmed fluids and 35.8+/-0.2 degrees C in the control group (P<0.05). The estimated reduction in heat loss provided by warming IV fluid was 217 kJ, a Value very close to the theoretical value expected from thermodynamic calculation. During recovery, one patient shivered in the group receiving warmed fluids and seven in the control group (P<0.05). Conclusion: In conclusion, infusion of warmed fluids, combined with skin-surface warming, helps to prevent hypothermia and reduces the incidence of postoperative shivering.