The management of chronic hypoventilation.

(Chest 1990; 98:474-80) C hronic alveolar hypoventilation, defined as a sustamed increase in PCO2 exceeding 45 mm Hg, is a condition commonly encountered by the chest physician. Most cases are related to chronic airway obstruction, but a substantial minority of cases have other contributing factors such as ventilatory control defects, respiratory muscle weakness, or a combination of factors. 1.2 Effective therapy requires that each of these factors be identified and addressed. The purpose of this review is to describe an approach to these patients that will consistently identify these other factors and to discuss the treatment of such patients with particular attention to the noninvasive modes of ventilatory assistance currently available. The pathophysiology of chronic alveolar hypoventilation has recently been reviewed in this journal,’ and will be considered only briefly.