Clinical question: Does the use of 80% oxygen perioperatively in abdominal surgery decrease the frequency of surgical-site infection within 14 days without increasing the rate of pulmonary complications?
Background: Low oxygen tension in wounds can negatively impact immune response and healing. Increasing inspiratory oxygen fraction during the perioperative period translates into higher wound oxygen tension. However, the benefit of increased oxygen fraction therapy in abdominal surgery healing and complications is not clear, nor is the frequency of pulmonary complications.
Study design: Patient- and observer-blinded clinical trial.
Setting: Fourteen Danish hospitals from October 2006 to October 2008.
Synopsis: Patients were randomized to receive a fraction of inspired oxygen (FIO2) of 0.80 or 0.30. The primary outcome—surgical-site infection in the superficial or deep wound or intra-abdominal cavity within 14 days of surgery—was defined using Centers for Disease Control and Prevention (CDC) criteria. Secondary outcomes included pulmonary complications within 14 days (pneumonia, atelectasis, or respiratory failure), 30-day mortality, duration of post-op course, ICU stay within 14 days post-op, and any abdominal operation within 14 days. The 1,386 patients were enrolled in the intention-to-treat analysis.
Infection occurred in 19.1% of patients given 0.80 FIO2 and in 20.1% of patients given 0.30 FIO2; odds ratio of 0.94 (95% CI 0.72 to 1.22; P=0.64). Numbers of pulmonary complications were not significantly different between the groups.
This trial included acute and nonacute laparotomies with followup for adverse outcomes. Study limitations included the inability to ensure that both groups received timely antibiotics and prevention for hypothermia. Of patients in the 30% FIO2 group, 7.3% required higher oxygen administration. Additionally, infection might have been underestimated in 11.3% of patients who were not followed up on between days 13 and 30.
Bottom line: High oxygen concentration administered during and after laparotomy did not lead to fewer surgical site infections, nor did it significantly increase the frequency of pulmonary complications or death.
Citation: Meyhoff CS, Wetterslev J, Jorgensen LN, et al. Effect of high perioperative oxygen fraction on surgical site infection and pulmonary complications after abdominal surgery: the PROXI randomized clinical trial. JAMA. 2009;302(14):1543-1550.