Oxygen Holds Negligible Benefit for Mild COPD

Oxygen therapy may not help chronic obstructive pulmonary disease (COPD) patients with moderate desaturation, according to a new study.

Researchers at Johns Hopkins University School of Medicine (Baltimore, MD, USA) conducted a randomized trial involving 738 patients with stable COPD and moderate exercise-induced desaturation. The patients were randomly assigned to receive long-term supplemental oxygen, or not. In the supplemental-oxygen group, patients with resting desaturation were prescribed 24-hour oxygen, while those with moderate desaturation – i.e., only during exercise – were prescribed oxygen during exercise and sleep.

The results, across 42 treatment centers and follow-up of 1-6 years, showed no significant difference between the supplemental-oxygen group and the group without added oxygen in time to death or first hospitalization, nor in total hospitalizations rates, COPD exacerbation rates, and COPD-related hospitalizations. There was no consistent between group differences in measures of quality of life, lung function, and the distance walked in six minutes. The study was published in the October 27, 2016, issue of the New England Journal of Medicine (NEJM).

“The consistency of the null findings strengthens the overall conclusion that long-term supplemental oxygen in patients with stable COPD and resting or exercise-induced moderate desaturation has no benefit with regard to the multiple outcomes measured,” concluded lead author Robert Wise, MD, and colleagues. “Our data support the conclusions of earlier studies that among patients with COPD who have a resting SpO2 of more than 88%, long-term treatment with supplemental oxygen does not result in longer survival than no long-term supplemental oxygen therapy, regardless of whether the patients have exercise-induced desaturation.”

“Since a lack of evidence of effect is not evidence of a lack of any clinical effectiveness, a trial of oxygen use might still be appropriate in selected patients with moderate exertional hypoxemia and intractable breathlessness despite appropriate evidence-based treatment,” commented Magnus Ekström, MD, PhD, of Lund University (Sweden), in an accompanying editorial. “I think that the oxygen treatment should be evaluated by means of blinded exercise tests while the patient is breathing ambient air or oxygen, and discontinued if the patient perceives no benefit during the test or within a day or two after it.”

Two trials that were conducted in the 1970s showed that long-term treatment with supplemental oxygen reduced mortality among patients with chronic obstructive pulmonary disease (COPD) and severe resting hypoxemia. These results led to the recommendation that supplemental oxygen be administered to patients with a SpO2 of less than 89%. In the 1990s, two other trials evaluated the long-term treatment with supplemental oxygen in patients with COPD who had mild-to-moderate daytime hypoxemia; neither trial showed a mortality benefit.

Related Links:
Johns Hopkins University School of Medicine
Lund University