The use of supplemental oxygen during cardiopulmonary resuscitation - a systematic review of the literature.
Resuscitation plus · 2026-04-27 · Systematic review
Abstract
PURPOSE: To evaluate whether the use of supplemental oxygen during cardiopulmonary resuscitation (CPR) improves outcomes after cardiac arrest. METHODS: We conducted a systematic review and registered the protocol PROSPERO (CRD420251243123). We searched 12 databases from inception to 27 October 2025 to identify studies evaluating supplemental oxygen use during CPR. Outcomes included return of spontaneous circulation (ROSC), survival, and survival with favorable neurological or functional outcome. Risk of bias was assessed using the Risk Of Bias In Non-randomized Studies of Interventions (ROBINS-I) tool. Evidence was synthesized narratively without meta-analysis. Hyperoxaemia was defined as PaO2 >300 mmHg (>40 kPa), normoxaemia as PaO2 60-300 mmHg (8-40 kPa), and hypoxaemia as PaO2 <60 mmHg (<8 kPa). RESULTS: Six studies met the inclusion criteria; all were observational. Five studies included out-of-hospital cardiac arrest patients, and one included in-hospital cardiac arrest patients. No study compared different inspired oxygen concentrations during CPR. The included studies provided indirect evidence as patients received an inspired oxygen fraction of 100%, and oxygen exposure was assessed using arterial blood gas measurements obtained during CPR. All studies were judged to be at critical risk of bias. Across studies, the prevalence of hyperoxaemia during CPR ranged from 2% to 21%, whereas hypoxaemia was more common, occurring in 20-72% of patients. Descriptively, patients with hyperoxaemia compared with patients with hypoxaemia had higher reported rates of ROSC (50-100% versus 21-58%), survival to hospital discharge (10-56% versus 1-16%), and favorable neurological or functional outcome (5-23% versus 0.5-3%). CONCLUSIONS: No studies directly comparing different supplemental oxygen strategies during CPR were identified. Very low-certainty indirect evidence from observational studies suggests an association between higher measured arterial oxygen levels during CPR and improved outcomes. These findings support current guideline recommendations to deliver the highest feasible inspired oxygen concentration during CPR, and highlight the need for randomized trials to evaluate oxygen strategies during CPR.Review registration: CRD420251243123 (https://www.crd.york.ac.uk/PROSPERO/view/CRD420251243123).