Weve done multiple columns questioning the likely overuse of oxygen and its potential untoward side effects, particularly in patients with stroke or myocardial infarction who are not hypoxemic (see list of those prior columns below).
While many studies have shown lack of benefit of oxygen in patients who are not hypoxemic, only some have suggested that the oxygen supplementation may actually be harmful. Now, a new systematic review and meta-analysis (Chu 2018) concludes that, n acutely ill adults, high-quality evidence shows that liberal oxygen therapy increases mortality without improving other patient-important outcomes. The new review included not only studies of patients with stroke or myocardial infarction but also patients with sepsis, critical illness, trauma, or cardiac arrest, and patients who had emergency surgery. In all, the review included 25 randomized controlled trials with 16,037 total patients.
Compared with a conservative oxygen strategy, a liberal oxygen strategy (median baseline saturation of peripheral oxygen [SpO2] across trials, 96%) increased mortality in-hospital (relative risk 1.21), and at 30 days (RR 1.14), and at longest follow-up (RR 1.10). Morbidity outcomes (disability at longest follow-up, risk of hospital-acquired pneumonia, any hospital-acquired infection, and length of hospital stay) were similar between groups.
They conclude that supplemental oxygen might become unfavorable above an SpO2 range of 9496% and that these results support the conservative administration of oxygen therapy.
Some of our prior columns on potential harmful effects of oxygen:
April 8, 2008 Oxygen as a Medication
January 27, 2009 Oxygen Therapy: Everything You Wanted to Know and More!
October 6, 2009 Oxygen Safety: More Lessons from the UK
July 2010 Cochrane Review: Oxygen in MI
December 6, 2011 Why You Need to Beware of Oxygen Therapy
February 2012 More Evidence of Harm from Oxygen
March 2014 Another Strike Against Hyperoxia
June 17, 2014 SO2S Confirms Routine O2 of No Benefit in Stroke
December 2014 Oxygen Should Be AVOIDed
August 11, 2015 New Oxygen Guidelines: Thoracic Society of Australia and NZ
Chu DK, Kim L H-Y, Young PJ, et al. Mortality and morbidity in acutely ill adults treated with liberal versus conservative oxygen therapy (IOTA): a systematic review and meta-analysis. Lancet 2018; 391(10131): 1693-1705, Published 28 April 2018