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

Background: Surgical site infection (SSI) causes significant mortality and morbidity. Administration of a high inspired oxygen fraction (FiO2) to patients undergoing surgery may represent a potential preventive strategy.

Aim: To conduct a meta-analysis of randomized controlled trials in which high FiO2 was compared with normal FiO2 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 FiO2 with normal FiO2 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 FiO2 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 FiO2 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.