- Last edited on March 29, 2021
Sleep-Related Hypoventilation
Primer
Sleep-related hypoventilation is a sleep disorder related to progressive respiratory impairment. When this disorder occurs comorbidly with other disorders (e.g., COPD, neuromuscular disorders, obesity), disease severity reflects the severity of the underlying condition, and the disorder progresses as the condition worsens.
Prevalence
- Idiopathic sleep-related hypoventilation in adults is very uncommon.
- The prevalence of congenital central alveolar hypoventilation is unknown, but the disorder is rare.
- Comorbid sleep-related hypoventilation (i.e., hypoventilation comorbid with other conditions, such as chronic obstructive pulmonary disease (COPD), neuromuscular disorders, or obesity) is the most common.
DSM-5 Diagnostic Criteria
Criterion A
Polysomnography demonstrates episodes of decreased respiration associated with elevated CO2 levels.
Criterion B
The disturbance is not better explained by another current sleep disorder.
Specifiers
Specifiers
Specify if:
- Idiopathic hypoventilation: This subtype is not attributable to any readily identified condition.
- Congenital central alveolar hypoventilation: This subtype isa rare congenital disorder in which the individual typically presents in the perinatal period with shallow breathing, or cyanosis and apnea during sleep.
- Comorbid sleep-related hypoventilation
Severity Specifier
Severity is graded according to the degree of hypoxemia and hypercarbia present during sleep and evidence of end organ impairment due to these abnormalities (e.g., right sided heart failure). The presence of blood gas abnormalities during wakefulness is an indicator of greater severity.
Pathophysiology
Children
Congenital central alveolar hypoventilation usually manifests at birth with shallow, erratic, or absent breathing. This disorder can also manifest during infancy, childhood, and adulthood because of variable penetrance of the PHOX2B mutation.
Adults
Pulmonary hypertension, cor pulmonale, cardiac dysrhythmias, polycythemia, neurocognitive dysfunction, and worsening respiratory failure can be the cause of sleep-related hypoventilation. The disorder severity corresponds with increasing severity of blood gas abnormalities.
Investigations
Polysomnography
Sleep-related hypoventilation is diagnosed using polysomnography showing sleep-related hypoxemia and hypercapnia that is not better explained by another breathing-related sleep disorder.
Arterial CO2
The documentation of increased arterial pC02 levels to greater than 55 mmHg during sleep or a 10 mmHg or greater increase in pC02 levels (to a level that also exceeds 50 mmHg) during sleep in comparison to awake supine values, for 10 minutes or longer, is the gold standard for diagnosis. However, obtaining arterial blood gas determinations during sleep is impractical, and non-invasive measures of pC02 have not been adequately validated during sleep and are not widely used during polysomnography in adults.
Oxygen Saturation
Prolonged and sustained decreases in oxygen saturation (oxygen saturation of less than 90% for more than 5 minutes with a nadir of at least 85%, or oxygen saturation of less than 90% for at least 30% of sleep time) in the absence of evidence of upper airway obstruction are often used as an indication of sleep-related hypoventilation; however, this finding is not specific, as there are other potential causes of hypoxemia, such as that due to lung disease.
Treatment
Differential Diagnosis
- Other medical conditions affecting ventilation
- Other breathing-related sleep disorders