Study objectives: Patients with COPD are at risk of experiencing a deterioration in arterial oxygen saturation (SaO2) during sleep, which is generally most pronounced during rapid eye movement (REM) sleep. Increased cholinergic tone has been suggested as a contributing factor to this decrease in SaO2. Therefore, we investigated whether 4-week treatment with ipratropium bromide inhalation solution 0.02% (qid) could improve sleep characteristics in COPD.
Design: Randomized, placebo-controlled, double-blind, two-arm parallel study of 4 weeks of treatment with ipratropium bromide solution or placebo.
Setting: Multicenter investigation.
Patients: Thirty-six patients with moderate-to-severe COPD (FEV1 < 65% of predicted).
Measurements and results: Evaluation included polysomnographic, pulmonary function, and subjective quality of sleep (visual analog scale [VAS]) assessments. It was found that 4 week of treatment with ipratropium bromide solution in patients with COPD led to the following: (1) a significant (p = 0.05) improvement in mean nocturnal SaO2 with the more severe the nocturnal desaturation, the greater the improvement in SaO2; (2) significant (p = 0.03) improvement in perceived sleep quality (VAS: 5.5 +/- 0.5 after placebo; 7.2 +/- 0.5 after ipratropium); (3) a significant (p = 0.05) increase in REM sleep time (48.6 +/- 6.3 min after placebo; 66.5 +/- 6.4 min after ipratropium) with no effect on other sleep stages or total sleep time; and (4) a significant (p = 0.01) increase in pre-sleep FVC and flow rate at 50% of the vital capacity.
Conclusions: These findings demonstrate that ipratropium bromide therapy can improve sleep SaO2 as well as sleep quality in patients with moderate-to-severe COPD.