Effects of Lung Volume Reduction Surgery on Sleep Quality and Nocturnal Gas Exchange in Patients With Severe Emphysema

Study objectives: We hypothesized that associated with improvements in respiratory mechanics, lung volume reduction surgery (LVRS) would result in an improvement in both sleep quality and nocturnal oxygenation in patients with severe emphysema.Design: Prospective randomized controlled trial.Setting: University hospital.Patients: Sixteen patients (10 men, 63 ± 6 years [± SD]) with severe airflow limitation (FEV1, 28 ± 10% predicted) and hyperinflation (total lung capacity, 123 ± 14% predicted) who were part of the National Emphysema Treatment Trial.Interventions and measurements: Patients completed 6 to 10 weeks of outpatient pulmonary rehabilitation. Spirometry, measurement of lung volumes, arterial blood gas analysis, and polysomnography were performed prior to randomization and again 6 months after therapy. Ten patients underwent LVRS and optimal medical therapy, while 6 patients received optimal medical therapy only.Results: Total sleep time and sleep efficiency improved following LVRS (from 184 ± 111 to 272 ± 126 min [p = 0.007], and from 45 ± 26 to 61 ± 26% [p = 0.01], respectively), while there was no change with medical therapy alone (236 ± 75 to 211 ± 125 min [p = 0.8], and from 60 ± 18 to 52 ± 17% [p = 0.5], respectively). The mean and lowest oxygen saturation during the night improved with LVRS (from 90 ± 7 to 93 ± 4% [p = 0.05], and from 83 ± 10 to 86 ± 10% [p = 0.03], respectively), while no change was noted in the medical therapy group (from 91 ± 5 to 91 ± 5 [p = 1.0], and from 84 ± 5 to 82 ± 6% [p = 0.3], respectively). There was a correlation between the change in FEV1and change in the lowest oxygen saturation during the night (r= 0.6, p = 0.02). In addition, there was an inverse correlation between the change in the lowest oxygen saturation during the night and the change in residual volume (-r= 0.5, p = 0.04) and functional residual capacity (-r= 0.6, p = 0.03).Conclusion: In patients with severe emphysema, LVRS, but not continued optimal medical therapy, results in improved sleep quality and nocturnal oxygenation. Improvements in nocturnal oxygenation correlate with improved airflow and a decrease in hyperinflation and air trapping.