Minimal Oxygen Supplementation Recommended for Most Inpatients

A new guidance statement reports that supplemental oxygen is not always indicated for acutely ill patients, and may contribute to higher mortality.

An expert panel from McMaster University (Hamilton, ON, Canada), Stellenbosch University (SU, South Africa), University Hospitals of Geneva (Switzerland), and other institutions convened to evaluated a recent systematic review and meta-analysis of 25 randomized controlled trials in order to develop recommendations for supplemental oxygen therapy in critically ill patients, surgical patients with sepsis, hospitalized patients, or patients en-route to hospital in an ambulance. Postoperative, obstetric, and pediatric patients were not included in the review.

The systematic review, which was published in The Lancet in April 2018, found that supplemental oxygen in inpatients with normal oxygen saturation increases mortality, and recommended that oxygen should be administered conservatively. The international panel of experts made several key recommendations, including maintaining peripheral oxygen saturation (SpO2) at or below 96% in patients on supplemental oxygen; in patients with acute myocardial infarction (MI) or stroke, oxygen should not be administered if the initial SpO2 is higher 92%. The guidance recommendations were published on October 24, 2018, in BMJ.

“It is a longstanding cultural norm to provide supplemental oxygen to sick patients, regardless of their blood oxygen saturation. A recent systematic review and meta-analysis has shown that too much supplemental oxygen increases mortality for medical patients in hospital,” concluded lead author Reed Siemieniuk, MD, PhD, of McMaster University, and colleagues. “A target SpO2 range of 90-94% seems reasonable for most patients, and 88-92% for patients at risk of hypercapnic respiratory failure seems wide enough to allow for normal fluctuation, and is likely low enough to avoid harm.”

The reasons as to why excessive supplemental oxygen increases mortality remain uncertain. Excessive oxygen can lead to reduced cardiac output, vasoconstriction, inflammation, and oxidative stress. In addition, excessive oxygen might lead to falsely reassuring SpO2 values and make it difficult to recognize when a patient’s condition worsens.

Related Links:
McMaster University
Stellenbosch University
University Hospitals of Geneva