O 2 No Longer the Go 2 : A Systematic Review and Meta-Analysis Comparing the Effects of Giving Perioperative Oxygen Therapy of 30% FiO 2 to 80% FiO 2 on Surgical Site Infection and Mortality.

Objective: To determine the effects of perioperative high (80%) versus low (30%) fraction of inspired oxygen (FiO ₂ ) on surgical site infection (SSI) and mortality in adult surgical patients.
Background: The routine use of high fraction perioperative oxygen in patients is "standard of care" and recommended by the World Health Organisation; however, whether there is truly any benefit to this therapy has been challenged by some authors. Questions have also been raised about the possibility of harm from oxygen therapy.
Method: Randomised control trials comparing high-to-low FiO ₂ were located by searching MEDLINE, Embase, CENTRAL and Web of Science. The primary outcomes were SSI up to 15 days and up to any time point postoperatively and mortality up to 30 days. The data were analysed using random effects meta-analysis.
Results: Twelve studies involving 10,212 participants were included. At 15 days postoperatively, and at the longest point of post-operative follow-up, there was no statistically significant reduction in the risk of SSI when comparing patients who received a perioperative FiO ₂ of 30% to those with an FiO ₂ of 80% (RR 1.41, 95% CI 1.00-2.01, p 0.05 and RR 1.23, 95% CI 1.00-1.51, p 0.05). There was no statistically significant difference in mortality between the 30% FiO ₂ and the 80% FiO ₂ groups (RR 1.12, 95% CI 0.56-2.22, p 0.76).
Conclusion: This meta-analysis showed no statistically significant difference in post-operative SSI or mortality when comparing patients receiving an FiO ₂ of 80% to those receiving an FiO ₂ of 30%.