Perioperative hypothermia in open and laparoscopic colorectal surgery

The consequences of even mild inadvertent perioperative hypothermia (IPH) are significant. There is a perception laparoscopic abdominal surgery is less prone to cause hypothermia than open surgery. However, during laparoscopic surgery, the peritoneal cavity is insufflated with carbon dioxide, which has a greater evaporative capacity than ambient air. This study compared the intra-operative temperature profile of patients undergoing open and laparoscopic colorectal surgery to define the incidence and severity of hypothermia.

All adult patients undergoing colorectal surgery between May 2005 and August 2013 were identified from an electronic database. Cases were categorized into laparoscopic and open cases. Hypothermic episodes were defined as a temperature less than 36°C lasting for more than two consecutive minutes. The incidence of hypothermic episodes, the total time under 36°C and the area under the curve (degree-minutes) were calculated.

A total of 1547 cases were analysed. The overall incidence of hypothermia was 67.0%. The incidence of cases with a hypothermic episode was greater in the laparoscopic group compared to the open group (71.23% versus 63.16%; chi-squared P-value 0.001). However, when other factors were considered, there was no significant difference in the relative risk of a hypothermic episode between types of surgery. There were significant differences in the severity of hypothermia.

Despite current measures to reduce the incidence, IPH remains a significant problem in colorectal surgery irrespective of the surgical approach. Further research is required to better characterize techniques that can reduce its incidence.