The consequences of sleep-related hypoventilation are related to the effects of chronic ex- posure to hypercapnia and hypoxemia. These blood gas derangements cause vasocon- striction of the pulmonary vasculature leading to pulmonary hypertension, which, if severe, can result in right-sided heart failure (cor pulmonale). Hypoxemia can lead to dys- function of organs such as the brain, blood, and heart, leading to outcomes such as cog- nitive dysfunction, polycythemia, and cardiac arrhythmias. Hypercapnia can depress ventilatory drive, leading to progressive respiratory failure.
Other medical conditions affecting ventilation. In adults, the idiopathic variety of sleep- related hypoventilation is very uncommon and is determined by excluding the presence of lung diseases, skeletal malformations, neuromuscular disorders, and other medical and neurological disorders or medications that affect ventilation. Sleep—related hypoventila- tion must be distinguished from other causes of sleep-related hypoxemia, such as that due to lung disease.
Other breathing-related sleep disorders. Sleep-related hypoventilation can be distin- features and findings on polysomnography. Sleep-related hypoventilation typically shows more sustained periods of oxygen desaturation rather that the periodic episodes seen in obstructive sleep apnea hypopnea and central sleep apnea. Obstructive sleep apnea hy- popnea and central sleep apnea also show a pattern of discrete episodes of repeated air- ﬂow decreases that can be absent in sleep-related hypoventilation.
Sleep-related hypoventilation often occurs in association with a pulmonary disorder (e.g., in- terstitial lung disease, COPD), with a neuromuscular or chest wall disorder (e.g., muscular dystrophies, post—polio syndrome, cervical spinal cord injury, obesity, kyphoscoliosis), or, most relevant to the mental health provider, with medication use (e.g., benzodiazepines, opi- ates). Congenital central alveolar hypoventilation often occurs in association with autonomic dysfunction and may occur in association with Hirschsprung’s disease. COPD, a disorder of lower airway obstruction usually associated with cigarette smoking, can result in sleep- related hypoventilation and hypoxemia. The presence of coexisting obstructive sleep apnea hypopnea is thought to exacerbate hypoxemia and hypercapnia during sleep and wakeful- ness. The relationship between congenital central alveolar hypoventilation and idiopathic sleep-related hypoventilation is unclear; in some individuals, idiopathic sleep-related hy— poventilation may represent cases of late-onset congenital central alveolar hypoventilation.
Relationship to Internationai Ciassification of
The International Classification of Sleep Disorders, 2nd Edition (ICSD-Z), combines sleep- related hypoventilation and sleep-related hypoxemia under the category of sleep-related hypoventilation/hypoxemic syndromes. This approach to classification reﬂects the fre- quent co-occurrence of disorders that lead to hypoventilation and hypoxemia. In contrast, the classification used in DSM-5 reflects evidence that there are distinct sleep-related pathogenetic processes leading to hypoventilation.
A. A persistent or recurrent pattern of sleep disruption that is primarily due to an alteration of the circadian system or to a misalignment between the endogenous circadian rhythm and the sleep—wake schedule required by an individual’s physical environment or social or professional schedule.
B. The sleep disruption leads to excessive sleepiness or insomnia, or both.
C. The sleep disturbance causes clinically significant distress or impairment in social, oc- cupational, and other important areas of functioning.
Coding note: For |CD-9-CM. code 307.45 for all subtypes. For |CD-10-CM. code is based on subtype.