Surgical Site Infection and the Routine Use of Perioperative Hyperoxia in a General Surgical Population

Abstract

Context Surgical site infection (SSI) in the general surgical population is a significant public health issue. The use of a high fractional inspired concentration of oxygen (FIO 2 ) during the perioperative period has been reported to be of benefit in selected patients, but its role as a routine intervention has not been investigated.Objective To determine whether the routine use of high FIO 2 during the perioperative period alters the incidence of SSI in a general surgical population.Design, Setting, and Patients Double-blind, randomized controlled trial conducted between September 2001 and May 2003 at a large university hospital in metropolitan New York City of 165 patients undergoing major intra-abdominal surgical procedures under general anesthesia.Interventions Patients were randomly assigned to receive either 80% oxygen (FIO 2 of 0.80) or 35% oxygen (FIO 2 of 0.35) during surgery and for the first 2 hours after surgery.Main Outcome Measures Presence of clinically significant SSI in the first 14 days after surgery, as determined by clinical assessment, a management change, and at least 3 prospectively defined objective criteria. ResultsThe study groups were closely matched in a large number of clinical variables. The overall incidence of SSI was 18.1%. In an intention-to-treat analysis, the incidence of infection was significantly higher in the group receiving FIO 2 of 0.80 than in the group with FIO 2 of 0.35 (25.0% vs 11.3%; P=.02). FIO 2 remained a significant predictor of SSI (P=.03) in multivariate regression analysis. Patients who developed SSI had a significantly longer length of hospitalization after surgery (mean [SD], 13.3 [9.9] vs 6.0 [4.2] days; PϽ.001). ConclusionsThe routine use of high perioperative FIO 2 in a general surgical population does not reduce the overall incidence of SSI and may have predominantly deleterious effects. General surgical patients should continue to receive oxygen with cardiorespiratory physiology as the principal determinant.

Non-pharmacologic Prevention of Surgical Wound Infection

“…In contrast, a subsequent report by Pryor et al [67] with only 160 patients reported that supplemental oxygen increases the risk of infection. It is thus worth considering why the results of Pryor et al differ so markedly from those of Greif et al [29].…”

“…It is thus worth considering why the results of Pryor et al differ so markedly from those of Greif et al [29]. Pryor et al [67] did not specify the baseline infection rate they used, making it impossible to confirm their estimate that 300 patients would be required to detect a 40% reduction in the infection rate. But to have an 80% power to detect the 40% risk reduction that they specified from 25% (our baseline) or from 11% (baseline from Greif et al [29]) would require 540 or 651 patients, respectively; to detect a 40% increase would require 698 or 930 patients, respectively.…”

“…A second factor is that Pryor's [67] treatment groups were not homogeneous. For example, in their study patients assigned to 80% oxygen weighed more and were more than twice as likely to have a body-mass index (BMI) exceeding 30 kg/m 2 .…”

Rational Hyperoxia in the Perioperative Period: a Safe and Effective Tool in the Reduction of SSI

“…It is interesting to observe that this study was terminated after 160 patients were enrolled early in view of increased infection rates in the hyperoxia group [21].…”

Review article: The anesthesiologist’s role in the prevention of surgical site infections

“…While not a primary end point of the ENIGMA study, the hyperoxia group did have a lower incidence of wound infections (adjusted OR 0.72; 95% CI 0.52 to 0.98; P = 0.036). 34 Conversely, Pryor et al 35 randomized 165 abdominal surgery patients to receive either 80% or 35% inspired oxygen over a similar time period. This study actually found that the rates of SSI were increased in the hyperoxia group (25.0% vs 11.3%; P = 0.03).…”