Routine use of oxygen in the treatment of myocardial infarction: systematic review.

CONTEXT: International guidelines recommend the routine use of oxygen therapy in the treatment of myocardial infarction (MI).

OBJECTIVE: To undertake a systematic review and meta-analysis of randomised placebo-controlled trials of oxygen therapy in MI.

DATA SOURCES: Medline, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, EMBASE and CINHAL.

STUDY SELECTION: Randomised placebo-controlled trials of oxygen therapy in MI.

DATA EXTRACTION: The primary clinical outcome was mortality.

RESULTS: Two of 51 potential studies met the inclusion criteria. The one study with substantive clinical outcome data reported that in uncomplicated MI, high-flow oxygen was associated with a non-significant increased risk of death (risk ratio 2.9, 95% CI 0.8 to 10.3, p = 0.08) and a greater serum aspartate aminotransferase level (difference 19.2 IU/ml, 95% CI 0 to 38.4, p = 0.05) than room air.

CONCLUSION: The limited evidence that does exist suggests that the routine use of high-flow oxygen in uncomplicated MI may result in a greater infarct size and possibly increase the risk of mortality.