The role of warmed-humidified carbon dioxide insufflation in colorectal surgery: A systematic review and meta-analysis.

Abstract

Maintenance of normothermia is a crucial part of enhanced recovery after colorectal surgery. Dry-cold carbon dioxide (CO₂ ) traditionally used for insufflation in laparoscopic surgery and negative pressure operating theatres has been associated with intraoperative hypothermia. Studies suggest that use of warmed-humidified CO₂ may promote normothermia. However, due to a scarcity of high-quality studies demonstrating a proven benefit on intraoperative core body temperature, its use in colorectal surgery remains limited. Therefore, the aim of this review was to evaluate the effects of warmed-humidified CO₂ compared to traditional dry-cold CO₂ , or ambient air in operating theatres, during colorectal surgery. A search of Medline, EMBASE, and CENTRAL was performed. Randomised controlled trials (RCTs) that compared patients receiving warmed-humidified CO₂ with either dry-cold CO₂ insufflation in laparoscopic procedures or no insufflation during open surgery were included. The primary outcome was change in intraoperative core body temperature. Secondary outcomes included length of stay, operating time, return of gastrointestinal function, wound infection, and postoperative pain. A pairwise meta-analysis was performed using inverse variance random effects. Among the six RCTs included, 208 patients received warmed-humidified CO₂ (42.3% female, mean age: 65.8 years) and 210 patients received either dry-cold CO₂ in laparoscopic procedures or no gas insufflation during open procedures (46.2% female, mean age: 66.1 years). No significant difference was found for change in intraoperative core body temperature (MD = 0.01, 95% CI: -0.1, 0.11, p = 0.90, very low certainty). Patients in the warmed-humidified CO₂ group had significantly higher pain scores on postoperative day 1 (MD = 1.61, 95% CI: 0.91, 2.31, p < 0.05, very low certainty). No significant differences were found in any of the other secondary outcomes studied. Patients undergoing colorectal surgery receiving warmed-humidified CO₂ do not experience any clinically meaningful difference in core body temperature change compared to their counterparts receiving dry-cold CO₂ insufflation or no insufflation. However, patients may report greater pain scores on postoperative day 1 with warmed-humidified CO₂ . There is likely no clinically important difference between warmed-humidified CO₂ and dry-cold CO₂ for patients undergoing colorectal surgery. Patient, clinician, and institution factors should be considered when deciding between these two insufflation modalities.