Sleep abnormalities and treatment in emphysema

Abstract

Sleep abnormalities are common in severe emphysema, and include poor sleep quality, the development of nocturnal oxygen desaturation, and the presence of coexistent obstructive sleep apnea. With lower baseline oxygenation and abnormal respiratory mechanics in patients with severe emphysema, alterations in ventilatory control and respiratory muscle function that normally occur during sleep can have profound effects, and contribute to the development of sleep abnormalities. The impact on quality of life, cardiopulmonary hemodynamics, and overall survival remains uncertain. In addition, treatment for chronic obstructive pulmonary disease and its effect on sleep abnormalities have demonstrated conflicting results. More recently, as part of the National Emphysema Treatment Trial, lung volume reduction surgery has been shown to improve both sleep quality and nocturnal oxygenation in emphysema. Although indications for performing an overnight polysomnogram in patients with emphysema have been debated, recommendations have been presented. Future studies investigating disease mechanism and response to therapy in patients with sleep abnormalities and severe emphysema are warranted.

Figure 1.

Potential consequences due to changes in ventilatory control and respiratory muscle function during sleep when they occur in patients with underlying chronic obstructive pulmonary disease (COPD). A/W = airways; OSA = obstructive sleep apnea; d/t = ratio of dead space volume to tidal volume.

Figure 2.

Effects of lung volume reduction surgery (LVRS) and medical therapy on total sleep time and sleep efficiency after 6 months. There was a significant improvement in total sleep time and sleep efficiency in the LVRS group, with no change noted in the medical therapy group. Reprinted by permission from Reference .

Figure 3.

There was a significant inverse correlation between the change in lowest Sa_O2 during the night (from baseline to 6 mo) and changes in residual volume and functional residual capacity (n = 16; r = −0.5, P = 0.04 and r = −0.6, P = 0.03, respectively). Reprinted by permission from Reference .