Chronic ventilatory failure caused by abnormal respiratory pattern generation during sleep

A 67-yr-old man presented with a 4-yr history of chronic ventilatory failure in the absence of any restrictive or obstructive ventilatory defect. Detailed neurologic investigations were unremarkable, and the response of minute volume of ventilation to inhaled CO2 was normal. During sleep there was no evidence of upper airway obstruction, and minute volume of ventilation averaged 6.7 L/min, compared with 7.2 L/min during quiet wakefulness. However, sleep was associated with a rapid and shallow pattern of breathing, resulting in high dead space ventilation, inadequate alveolar ventilation, hypoxemia, and hypercapnia. Correction of the abnormal ventilatory pattern during sleep by diaphragmatic pacing abolished all features of chronic respiratory failure. The findings indicate that a disorder of respiratory pattern during sleep can produce chronic ventilatory failure, despite normal respiratory drive.