Sleep-related disorders in chronic obstructive pulmonary disease

Abstract

Sleep may have several negative consequences in patients with chronic obstructive pulmonary disease (COPD). Sleep is typically fragmented with diminished slow wave and rapid-eye-movement sleep, which likely represents an important contributing factor to daytime symptoms such as fatigue and lethargy. Furthermore, normal physiological adaptations during sleep, which result in mild hypoventilation in normal subjects, are more pronounced in COPD, which can result in clinically important nocturnal oxygen desaturation. The co-existence of obstructive sleep apnea and COPD is also common, principally because of the high prevalence of each disorder, and there is little convincing evidence that one disorder predisposes to the other. Nonetheless, this co-existence, termed the overlap syndrome, typically results in more pronounced nocturnal oxygen desaturation and there is a high prevalence of pulmonary hypertension in such patients. Management of sleep disorders in patients with COPD should address both sleep quality and disordered gas exchange. Non-invasive pressure support is beneficial in selected cases, particularly during acute exacerbations associated with respiratory failure, and is particularly helpful in patients with the overlap syndrome. There is limited evidence of benefit from pressure support in the chronic setting in COPD patients without obstructive sleep apnea.

Keywords::

• cardiovascular co-morbidity
• COPD
• hypoxemia
• inflammation
• obstructive sleep apnea
• pathophysiology
• sleep

Financial and competing interests disclosure

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

No writing assistance was utilized in the production of this manuscript.

Key issues

• In normal subjects during sleep, physiological changes are not associated with any clinically significant deterioration in gas exchange but in chronic obstructive pulmonary disease (COPD) patients these changes can result in clinically significant hypoxemia.

• In COPD patients, subjective and objective sleep quality is impaired.

• COPD and obstructive sleep apnea (OSA) can co-exist in the same patient (the Overlap syndrome), both being prevalent conditions, and have complex interrelated pathophysiology.

• OSA and COPD are independently associated with an increased cardiovascular risk, and this effect may be augmented in the Overlap Syndrome.

• Disturbed sleep quality as well as worsened gas exchange during sleep should be addressed when considering management of sleep disorders in COPD.

• When managing patients with the overlap syndrome, the choice between continuous (CPAP) and bi-level positive airway pressure can be determined based on the pattern of sleep-disordered breathing.

• The beneficial role of non-invasive ventilation is well documented in acute exacerbations of COPD, but benefits are less clear-cut for long-term CPAP in patients with stable COPD. However, patients with the overlap syndrome have improved survival with long-term CPAP.

Notes