Nocturnal oxygen for COPD patients who do not qualify for daytime oxygen is unlikely to be helpful (INOX)

Référence

Lacasse Y, Series F, Corbeil F, et al, for the INOX Trial Group. Randomized trial of nocturnal oxygen in chronic obstructive pulmonary disease. N Engl J Med 2020;383(12):1129-1138.

Sommaire

Nocturnal hypoxemia occurs in some patients with chronic obstructive pulmonary disease (COPD) who do not have apnea and do not ordinarily qualify for oxygen therapy on the basis of their daytime desaturations. In the current study, researchers identified 243 Canadian adults with COPD and a FEV1 of less than 70% of predicted, who did not have daytime hypoxemia severe enough to receive oxygen, had an apnea hypopnea index of less than 15 events per hour, and had documented nighttime desaturations with oxygen saturation less than 90% for at least 30% of their time in bed. The patients were randomized to receive home nocturnal oxygen using a concentrator or to ambient air provided by a sham concentrator. Flow was titrated to maintain at least 90% oxygen saturation for at least 90% of the time in bed, up to 4 liters per minute. Groups were balanced at the start of the study, with a mean age of 69 years; 65% of both groups were men. Patients were followed up for at least 3 years. The primary outcome — death from any cause or a requirement for long-term oxygen supplementation due to deterioration at 3 years — was the same between groups (39% for oxygen vs 42% for sham; P = .64), and there was no difference for the individual components of the composite and no difference at 4 years. An important limitation of this trial was that the researchers fell far short of their target enrollment of 600 patients. But they identified 2 other small trials and when they used meta-analysis to add these results to their own, they still found no benefit of noctural oxygen therapy.