Effects of Epidural Anaesthesia on Intraoperative Core Temperature Changes in Colorectal Cancer Surgery

The purpose of our study was to compare two different methods of anaesthesia in colorectal cancer surgery with respect to the level of intra-operative heat loss and to evaluate its influence on surgical outcome. One hundred patients scheduled to undergo elective colorectal cancer surgery were randomised to receive general anaesthesia (GEN group) or combined general and epidural anaesthesia (GEN + EA group), with 50 patients in each group. Induction and maintenance of general anaesthesia were performed the same way in both groups. Core temperature in lower 1/3 of oesophagus was measured every five minutes after induction of anaesthesia till the end of the surgery. All postoperative complications were registered. There were no significant differences between both groups in respect to patient characteristics and operations carried out. Core temperature decreased during surgery from 36.5 ± 0.4 °C to 36.0 ± 0.5 °C in the GEN group, compared to 36.3 ± 0.4 °C to 35.7 ± 0.6 °C in GEN + EA group. Moreover, heat loss in the GEN + EA group was significantly higher (P < 0.05) than in the GEN group. Surgical complications occurred in four (8%) patients in GEN group and eleven (22%) in the GEN + EA group (P = 0.09). Our study showed that heating of intravenous infusion fluids is not enough to protect from heat loss intraoperatively. Oesophageal core temperature decreased in all patients, but heat loss was greater in the combined general and epidural anaesthesia group. It seems likely that mild hypothermia is an important risk factor in the development of postoperative surgical complications.