BACKGROUND: It has been suspected that laparoscopic surgery exacerbates hypothermia to a greater extent than open surgery. Thus, this study was designed to compare the intraoperative thermoregulatory profiles of three different operative techniques: open surgery, low pressure (LP: 8 mmHg) or conventional pressure (CP: 13 mmHg) laparoscopic surgery.
METHODS: Forty five patients who were scheduled for radical hysterectomy were allocated to three groups, 15 in each group: group O (open surgery), group LP and group CP. Anesthesia was maintained with 2.5% sevoflurane. Intraoperative core temperature and forearm minus fingertip skin temperature gradients were measured at 15-min intervals during the first three hours. Vasoconstriction threshold was defined by the esophageal temperature at which the skin temperature gradient equalled 0℃.
RESULTS: All groups were comparable in terms of the characteristics of patients and preoperative body temperatures. Core temperatures and forearm minus fingertip skin temperature gradients were not significantly different among the three groups at all measurements. Thermoregulatory vasoconstrictions were observed in 6 of group O and 6 of laparoscopic surgical patients (4 patients from group LP and 2 patients from group CP). These 12 patients were divided into open (n = 6) and laparoscopic (n = 6) surgery group. There were no significant difference between the groups with regard to the vasoconstriction threshold and threshold time.
CONCLUSIONS: Laparoscopic procedures with conventional insufflation pressure have similar profiles in terms of intraoperative thermoregulation, when compared to open surgery. Lowering insufflation pressure to 8 mmHg can not reduce the risk of intraoperative hypothermia.