Mortality and morbidity in acutely ill adults treated with liberal versus conservative oxygen therapy (IOTA): a systematic review and meta-analysis

Oxygen was first described as a treatment in acute care in 1885. In contemporary clinical practice, supplemental oxygen is frequently administered to acutely ill patients — approximately 34% of patients in ambulances, 25% of individuals in emergency rooms, and 15% of patients admitted to hospital3 in the UK. In these settings, 50–84% of patients are exposed to excess oxygen and hyperoxaemia as a result of efforts to prevent or reverse hypoxaemia. Furthermore, many health-care providers consider supplemental oxygen a harmless and potentially beneficial therapy, irrespective of the presence or absence of hypoxaemia.

Lancet. 2018 Apr 28;391(10131):1693-1705. doi: 10.1016/S0140-6736(18)30479-3