Nocturnal oxygen therapy in patients with chronic obstructive pulmonary disease: a survey of Canadian respirologists.

backgroundCurrent evidence does not clearly support the provision of nocturnal oxygen therapy in patients with chronic obstructive pulmonary disease (COPD) who desaturate during sleep but who would not otherwise qualify for long-term oxygen therapy (LTOT).

objectivesTo characterize the perception and clinical practice of Canadian respirologists regarding the indications and prescription of nocturnal oxygen therapy in COPD, and to determine what Canadian respirologists consider an important treatment effect of nocturnal oxygen therapy in a randomized, placebo-controlled trial.

methodsA mail survey of all the respirologists registered in the 2006 Canadian Medical Directory was conducted.

resultsA total of 543 physicians were surveyed. The response rate was 60%, and 99% of the respondents indicated that the problem of nocturnal oxygen desaturation is clinically relevant. Eighty-two per cent interpret oximetry tracings themselves, and 87% have access to a sleep laboratory. Forty-two per cent believe that all COPD patients with significant nocturnal desaturation should have a polysomnography to rule out sleep apnea, and 41% would prescribe nocturnal oxygen therapy to active smokers. Assuming a risk of death or progression to LTOT of 40% over a three-year period, the respirologists indicated that to declare nocturnal oxygen therapy effective in reducing the rate of major clinical events in a clinical trial, the minimal absolute risk difference of death or progression to LTOT between oxygen and room air breathing should be 14%.

conclusionsCanadian respirologists are interested in the issue of nocturnal oxygen desaturation in COPD. There is variation in clinical practices among Canadian respirologists in several aspects of the management of this problem.