What’s New in the Patient Safety World

June 2018

Too Much Oxygen



We’ve 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 94–96% 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!”

April 2009 “Nursing Companion to the BTS Oxygen Therapy Guidelines”

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”

November 2016 “Oxygen Tank Monitoring”

November 2016 “More on Safer Use of Oxygen”

October 2017 “End of the Oxygen in MI and Stroke Debate?”

February 2018 “Oxygen Cylinders Back in the News”






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







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