title: Intraoperative local insufflation of warmed humidified CO₂ increases open wound and core temperatures: a randomized clinical trial.
abstract: BACKGROUND
  The open surgical wound is exposed to cold dry ambient air, resulting in substantial heat loss through radiation, evaporation, and convection. At the same time, anesthesia decreases the patient's core temperature. Despite preventive measures, mild intraoperative hypothermia has been associated with postoperative morbidity. We hypothesized that local insufflation of warmed humidified carbon dioxide (CO(2)) would maintain wound and core temperature.
  
  
  METHODS
  Eighty patients undergoing open colon surgery were randomized to standard warming measures, or to additional local wound insufflation of warmed (30 °C) humidified (93 % rH) CO(2) via a gas diffuser. Surface temperature of the open abdominal wound was measured with a heat-sensitive infrared camera, and core temperature was measured with an ear thermometer.
  
  
  RESULTS
  Mean operative time was 219 ± 104 and 205 ± 85 min in the CO(2) group and the control group, respectively (p = 0.550). Clinical variables did not differ significantly between the groups. The median wound area and wound edge temperatures were 1.2 °C (p < 0.001) and 1.0 °C (p = 0.002) higher in the CO(2) group, respectively, than in the control group. The mean core temperature after intubation was the same (35.9 °C) in both groups, but at end of surgery core temperature in the two groups differed, with a mean of 36.2 ± 0.5 °C in the CO(2) group and a mean of 35.8 ± 0.5 °C in the control group (p = 0.003).
  
  
  CONCLUSIONS
  Insufflation of warmed, humidified CO(2) in an open surgical wound cavity prevents intraoperative decrease in surgical wound temperature as well as core temperature.
authors.affiliation: Department of Molecular Medicine and Surgery, Karolinska Institute/Karolinska University Hospital, 171 76 Stockholm, Sweden. joana.frey@ki.se
authors.forename: Joana M K
authors.initials: JM
authors.lastname: Frey
authors.forename: Martin
authors.initials: M
authors.lastname: Janson
authors.forename: Monika
authors.initials: M
authors.lastname: Svanfeldt
authors.forename: Peter K
authors.initials: PK
authors.lastname: Svenarud
authors.forename: Jan A
authors.initials: JA
authors.lastname: van der Linden
mesh_terms: D000005:Abdomen / Q000601:surgery*; D000368:Aged; D001831:Body Temperature; D002245:Carbon Dioxide / Q000008:administration & dosage*; D005260:Female; D006358:Hot Temperature; D006801:Humans; D006813:Humidity; D007327:Insufflation; D007430:Intraoperative Care / Q000379:methods*; D008297:Male; D008875:Middle Aged
chemical_list: D002245:Carbon Dioxide