Abstract

In most patients with acute myocardial infarction arterial oxygen tension is reduced.¹ Because of the shape of the oxygen dissociation curve the fall in oxygen saturation is probably insignificant. The practice of giving oxygen aims to correct this hypoxaemia² so enhancing delivery of oxygen to the surrounding ischaemic area and limiting the final size of the infarct,³ preventing arrhythmias⁴ and relieving pain.⁵ Whether the inhalation of a high concentration of oxygen helps is not clear. Marginal benefits have been claimed after hyperbaric oxygen⁶ but this is expensive and not generally available.