1. Safety of 80% vs 30–35% fraction of inspired oxygen in patients undergoing surgery: a systematic review and meta-analysis 
Katharina Mattishent, Menaka Thavarajah, Ashnish Sinha, Adam Peel, Matthias Egger, Joseph Solomkin, Stijn de Jonge, Asad Latif, Sean Berenholtz, Benedetta Allegranzi, Yoon Kong Loke 
British Journal of Anaesthesia 
Volume 122, Issue 3, Pages (March 2019)
DOI: /j.bja
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2. Fig 1 Flowchart of study selection.
British Journal of Anaesthesia  , DOI: ( /j.bja )
Copyright © 2018 World Health Organization Terms and Conditions

3. Fig 2
Pooled risk ratio for adverse events. CI, confidence interval; M-H, Mantel-Haenszel.
British Journal of Anaesthesia  , DOI: ( /j.bja )
Copyright © 2018 World Health Organization Terms and Conditions

4. Fig 3
Pooled risk ratio for death, including short- and long-term follow-up.
British Journal of Anaesthesia  , DOI: ( /j.bja )
Copyright © 2018 World Health Organization Terms and Conditions