Sleep-related hypoventilation due to a medication or substance (Q41270)

Sleep-related hypoventilation due to a medication or substance is characterised primarily by chronic hypoventilation and hypercapnia due to prolonged use of medications or substances known to depress ventilatory drive and/or impair respiratory muscle mechanics (e.g. long-acting narcotics, anesthetics, sedative compounds, and muscle relaxants). Hypoxemia is commonly present as well. Hypercapnia may also be present during wakefulness in some patients. Patients can either be asymptomatic or present with complaints of dyspnea, chest tightness, or fatigue. Note: A definitive diagnosis requires objective evidence based on polysomnography with carbon dioxide (CO2) monitoring (by arterial, end-tidal or transcutaneous measures) in the context of medication or substance use that is judged to be causing the symptoms.