In classic teaching in medical school, we were told to give supplemental oxygen to patients with myocardial infarction. But in the era of evidence based medicine this may be not true for everyone. The AVOID trial has addressed tis issue. The AVOID investigators has found that oxygen in the non-hypoxic STEMI patients was associated with increased infarction size (detected by CMR), increased rate of re-infarction and increased incidence of ventricular arrhythmias. So, it is not recommended to give supplemental oxygen if the patient is not hypoxic on room-air, i.e. the patient has SO
2 above 94%. This may be explained by the increased formation of oxygen free radicles that are associated with more myocardial injury (chemical rather than ischemic).
This is a link to the AVOID study results.
