Supplemental oxygen during colorectal surgery reduces risk of wound infection

Patients who received a higher concentration of supplemental oxygen during colorectal surgery had a significantly reduced risk of wound infection, according to a study in the October 26 issue of JAMA: The Journal of the American Medical Association.

Surgical wound infections prolong hospitalization by an average of 1 week and substantially increase the cost of care, according to background information in the article. These infections are possibly the most common serious complication of surgery and anesthesia. Supplemental oxygen during and after surgery has been variously reported to halve or double the risk of surgical wound infection.

F. Javier Belda, M.D., Ph.D., of the Hospital Clínico Universitario de Valencia, Spain, and colleagues conducted a study to determine whether supplemental perioperative (performed at or around the time of an operation) oxygen reduces the risk of wound infection. The double-blind, randomized controlled trial included 300 patients aged 18 to 80 years who underwent elective colorectal surgery in 14 Spanish hospitals from March 1, 2003, to October 31, 2004. Baseline patient characteristics, anesthetic treatment, and potential confounding factors were recorded. Patients were randomly assigned to an oxygen/air mixture with a fraction (concentration) of inspired oxygen (Fio2) of 30 percent or 80 percent intraoperatively and for 6 hours after surgery.

A total of 143 patients received 30 percent perioperative oxygen and 148 received 80 percent perioperative oxygen. Surgical site infection (SSI) occurred in 35 patients (24.4 percent) administered 30 percent Fio2, and in 22 patients (14.9 percent) administered 80 percent Fio2.

" … we found that 80 percent supplemental oxygen reduced the risk of SSI by 39 percent. When controlling for multiple contributing factors, the reduction in SSI risk associated with 80 percent Fio2 was nearly 54 percent. Patients with infections had significantly longer hospital stays and delays to ambulation," the researchers write.

"This result is consistent with most available in vitro data and 1 other appropriately designed randomized controlled trial. Supplemental oxygen appears to confer few risks to the patient, has little associated cost, and should be considered part of ongoing quality improvement activities related to surgical care," the authors conclude.