Nocturnal Oxygen No Help for Isolated Desaturation in COPD

Medscape
17 Sep, 2020 ,

According to findings published September 16 in The New England Journal of Medicine, nocturnal oxygen therapy for patients with COPD and isolated nocturnal oxygen desaturation does not improve survival or delay disease progression. "There is no indication that nocturnal oxygen has a positive or negative effect on survival or progression to long-term oxygen therapy in patients with nocturnal hypoxemia in COPD. Consequently, there is no reason for physicians to screen for nocturnal hypoxemia in COPD," said the study leader Yves Lacasse

Source
Full content

Nocturnal oxygen therapy for patients with COPD and isolated nocturnal oxygen desaturation does not improve survival or delay disease progression, according to findings published September 16 in The New England Journal of Medicine. The new report adds to evidence that the widely implemented and costly practice may be unnecessary.

Patients with COPD who do not qualify for long-term oxygen therapy (LTOT) are commonly prescribed nocturnal oxygen in the belief that it can delay disease progression, possibly by decreasing alveolar hypoventilation and ventilation-perfusion mismatch.

But investigations so far and the new study from the International Nocturnal Oxygen (INOX) Trial have not borne this out.

"There is no indication that nocturnal oxygen has a positive or negative effect on survival or progression to long-term oxygen therapy in patients with nocturnal hypoxemia in COPD. Consequently, there is no reason for physicians to screen for nocturnal hypoxemia in COPD," study leader Yves Lacasse, MD, told Medscape Medical News.

Lacasse is from the Institut Universitaire de Cardiologie et de Pneumologie de Québec–Université Laval, Quebec, Canada.

The idea that the therapy helps is firmly entrenched.

In the early 1980s, two trials indicated that patients who had COPD and severe chronic daytime hypoxemia benefit from LTOT (15 to 18 hours a day or longer).

A decade later, two landmark trials (the Nocturnal Oxygen Therapy Trial and the British Medical Research Council Trial) added to evidence that LTOT may prolong life for patients with COPD and severe daytime hypoxemia.

"The good news from both trials was that oxygen saves lives. From this moment, oxygen therapy became a standard of care, and confirmatory trials would be considered unethical," Lacasse explained.

"Oxygen therapy gained widespread acceptance by official organizations for treatment of most chronic cardiorespiratory conditions complicated by severe hypoxemia, even if proof of efficacy is lacking. New indications emerged, such as isolated nocturnal oxygen desaturation. Even in COPD, inappropriate prescriptions of home oxygen therapy are not unusual. Oxygen is everywhere," Lacasse continued.

A meta-analysis from 2005 identified two trials that evaluated home oxygen therapy specifically for isolated nocturnal desaturation. Both found no survival benefit from nocturnal oxygen.

The study by Lacasse and colleagues assessed effects on mortality or worsening of disease (progression to LTOT) with 3 to 4 years of nocturnal oxygen supplementation.

Participants, whose oxygen saturation was less than 90% for at least 30% of the recording time on nocturnal oximetry, received oxygen or ambient air from a sham device as a placebo for at least 4 hours per session. The goal of treatment was nocturnal oxygen saturation exceeding 90% for at least 90% of the recorded time.