Does intra-operative humidification with warmed CO2 reduce surgical site infection in open colorectal surgery? A randomized control trial

Backgrounds: Surgical site infections (SSI) are a significant cause of postoperative morbidity and mortality, contributing to a considerable financial burden on the healthcare system. Insufflation of the open surgical wound with warm, humidified carbon dioxide (CO2) is a novel measure aimed to reduce SSI. The local atmosphere of warm, humidified CO2 within the open surgical wound is proposed to decrease airborne contamination, bacterial growth, desiccation, and heat loss while improving tissue oxygenation and perfusion. This randomized controlled trial evaluates the impact of the HumiGard (TM) surgical humidification system on the incidence of SSI in patients undergoing open colorectal surgery. Methods: We conducted a multi-site single-blinded randomized control trial on patients undergoing elective or emergency laparotomy at a single tertiary Colorectal Surgery service. The primary outcome measure was the incidence of SSI, with secondary outcomes including ICU length of stay (LOS), total LOS and mean core temperature. Results: Patients who received HumiGard (TM) had a lower incidence of SSI, although this did not reach statistical significance (4.5% for treatment group versus 13.0% for control group; P = 0.092). There was no significant difference in ICU LOS or total LOS between cohorts. The HumiGard (TM) group had a higher mean core temperature than the control at the end of surgery (P < 0.001). Conclusion: The present study could not confirm that utilization of warm, humidified CO2 with HumiGard (TM) reduces SSI in open colorectal surgery. Further research is indicated to validate and extend these findings.