Effect of intra-operative high inspired oxygen fraction on surgical site infection: a meta-analysis of randomized controlled trials

Summary Background Surgical site infection (SSI) causes significant mortality and morbidity. Administration of a high inspired oxygen fraction (FiO 2 ) to patients undergoing surgery may represent a potential preventive strategy. Aim To conduct a meta-analysis of randomized controlled trials in which high FiO 2 was compared with normal FiO 2 in patients undergoing surgery to estimate the effect on the development of SSI. Methods A comprehensive search was undertaken for randomized controlled trials (until December 2015) that compared high FiO 2 with normal FiO 2 in adults undergoing surgery with general anaesthesia and reported on SSI. Findings This study included 17 randomized controlled trials with 8093 patients. Infection rates were 13.11% in the control group and 11.53% in the hyperoxic group, while the overall risk ratio was 0.893 [95% confidence interval (CI) 0.794–1.003; P = 0.057]. Subgroup analyses stratified by country, definition of SSI, and type of surgery were also performed, and showed similar results. However, high FiO 2 was found to be of significant benefit in patients undergoing colorectal surgery, with a risk ratio of 0.735 (95% CI 0.573–0.944; P =0.016). Conclusions There is moderate evidence to suggest that administration of high FiO 2 to patients undergoing surgery, especially colorectal surgery, reduces the risk of SSI. Further studies with better adherence to the intervention may affect the results of this meta-analysis.