Study Questions Long-Term Supplemental Oxygen for COPD Patients

In patients with stable chronic obstructive pulmonary disease (COPD) and resting or exercise-induced moderate desaturation, long-term supplemental oxygen did not result in a longer time to death or first hospitalization compared with no long-term supplemental oxygen, nor did it provide sustained benefit with regard to any of the other measured outcomes, according to a new study.

The researchers originally designed the trial to test whether long-term treatment with supplemental oxygen would result in a longer time to death than no use of supplemental oxygen among patients who had stable COPD with moderate resting desaturation (oxyhemoglobin saturation as measured by pulse oximetry [SpO₂], 89%-93%). After 7 months and the randomization of 34 patients, they redesigned the trial to also include patients who had stable COPD with moderate exercise-induced desaturation (during the 6-minute walk test, SpO₂ ≥80% for ≥5 minutes and <90% for ≥10 seconds) and to incorporate the time to the first hospitalization for any cause into the new composite primary outcome.
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The investigators randomly assigned patients in a 1:1 ratio to receive long-term supplemental oxygen or no long-term supplemental oxygen. In the supplemental-oxygen group, patients with resting desaturation were prescribed 24-hour oxygen, and those with desaturation only during exercise were prescribed oxygen during exercise and sleep. The researchers did not mask the trial-group assignment.

They followed the cases of 738 patients at 42 centers for 1 to 6 years. In a time-to-event analysis, the researchers found no significant difference between the supplemental-oxygen group and the no-supplemental-oxygen group in the time to death or first hospitalization, nor in the rates of all hospitalizations, COPD exacerbations, and COPD-related hospitalizations. The investigators also found no consistent between-group differences in measures of quality of life, lung function, and the distance walked in 6 minutes.

The study had several limitations, the researchers noted, including that some patients may not have enrolled in the trial because they or their providers believed they were too ill or that they benefited from oxygen; that they did not use uniform devices for oxygen delivery; and that they did not assess the immediate effects of oxygen on symptoms or exercise performance.

—Mike Bederka

Reference:

Long-Term Oxygen Treatment Trial Research Group. A randomized trial of long-term oxygen for COPD with moderate desaturation. N Engl J Med. 2016;375(17):1617-1627. doi:10.1056/NEJMoa1604344.