Effectiveness of supplemental oxygenation to prevent surgical site infections: A systematic review with meta-analysis.

The analysis was split by surgery type, which made each subgroup smaller. Patients and infection evaluators could be blinded, but anesthesiologists could not, because they had to deliver the assigned oxygen level. Postoperative oxygen duration and delivery method varied across trials, and guidelines did not specify how to administer it. Four trials were stopped early because continuing was judged unlikely to show a difference. C-section trials were limited by spinal or epidural anesthesia and by mask or nasal catheter fit, which can make oxygen delivery less constant. Few trials reported potential harms such as lung injury or oxidative stress, so safety is not well established. The authors state that the included trials were inconclusive for guiding a change in practice.

The study was financed in part by Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, Finance Code 001, Brazil. No other conflicts of interest are stated in the supplied text.

Do not read this as evidence that high perioperative oxygen prevents surgical site infection in all surgeries. The pooled benefit was clear only for colorectal surgery; the C-section and abdominal surgery groups did not show a clear reduction.