[Primary alveolar hypoventilation in adulthood]

Central alveolar hypoventilation in an adult is characterized by dysfunction of the respiratory center in the brainstem and is very rare, seen mostly secondary to neurological lesions of the brainstem.

We report a 48-year-old man with primary alveolar hypoventilation associated with marked cardiac arrhythmias and hemodynamic changes. Arterial blood gas analysis revealed daytime hypoxemia and hypercapnia not explained by normal pulmonary results. All night polysomnography showed sleep fragmentation following repetitive central apneas and hypoventilation with marked hypoxemia and the lowest saturation in REM sleep. Severe nocturnal hypoxemia was accompanied by marked hypercapnia. Premature ventricular complexes occurred associated with nocturnal hypoxemia in NREM sleep while sinus arrest of up to 11.3 s were only seen associated with hypoxemia in REM sleep. Pulmonary arterial pressures were normal when the patient was awake with marked increases in pulmonary arterial pressures associated with hypoventilation and changes in arterial oxygen saturation with the patient was asleep.

Nasal positive pressure ventilation was effectively able to treat central apneas and hypoventilation, nocturnal hypoxemia and cardiac arrhythmias were no longer observed. Also, daytime arterial blood gases were normal with nocturnal nasal mechanical ventilation.