Association between intra- and post-arrest hyperoxia on mortality in adults with cardiac arrest: A systematic review and meta-analysis

Myocardial injury and mortality in patients with excessive oxygen administration before cardiac arrest

“…We were unable to find other studies that have examined pre‐arrest oxygen exposure. Several observational studies are suggesting a strong association between hyperoxia and mortality, however, these studies are all assessing post‐arrest hyperoxia …”

“…Patel et al included 10 observational studies in a meta‐analysis, all studies defined hyperoxia as PaO 2 > 300 mm Hg (40 kPa) and had in‐hospital death or survival to discharge as outcome assessment. They found that post‐arrest hyperoxia was associated with higher mortality (OR 1.34, 95% CI 1.08‐1.67).…”

“…Hypoxia is normally defined as PaO 2 <60 mm Hg (8 kPa) and hyperoxia is defined as PaO 2 >300 mm Hg. (40 kPa) which results in a large normoxic range. We found all our patients to be within 60‐300 mm Hg within 48 hours after CA.…”

“…We were limited by the fact that we had no PaO 2 values before CA, since a high SpO 2 does not necessary reflects that a patient is severely hyperoxic . Most studies investigating the role of hyperoxia uses PaO 2 . SpO 2 is, however, still a strong indicator and we considered it as the best parameter of oxygenation available.…”

“…A cohort study suggested early post‐resuscitation hyperoxia as an independent predictor of poor neurological function . Several observational studies, including two large meta‐analyzes indicate hyperoxia after ROSC to be associated with increased mortality, however, the results are conflicting, since other observational studies report no association between initial post‐arrest hyperoxia and mortality …”