Sleep disorders in COPD

In patients with chronic obstructive pulmonary disease (COPD, defined as a combination of emphysema and chronic bronchitis), sleep quality and architecture are often altered. The very common nocturnal symptoms of cough, dyspnea, chest tightness, and wheezing disturb sleep and lead to daytime dissatisfaction and additional symptoms in these patients. Sleep is often fragmented, while rapid eye movement sleep is generally diminished in duration. Due to nocturnal symptoms and possibly the use of certain medications, some patients with COPD experience difficulty initiating or maintaining sleep, symptoms that define insomnia. The known physiological changes that occur during sleep may have more profound consequences in COPD, such as persistent hypoxia and hypercapnia. The comorbid association of obstructive sleep apnea (OSA) and COPD (the “overlap syndrome”) may lead to more severe and persistent nocturnal hypoxemia and development of pulmonary hypertension, cor pulmonale, cardiac arrhythmia, and even sudden cardiac death. Diagnosing sleep abnormalities in patients with COPD is important, as it should address not only poorer sleep quality, but also co-existent sleep disordered breathing or other sleep conditions.