Central alveolar hypoventilation syndrome

Abstract

Alveolar hypoventilation of central origin and primary in appearance was described over 30 years ago: it is characterised by considerable daytime hypoxemia-hypercapnia, but which is often well-tolerated, and by the abolition of the ventilatory response to a hypercapnic stimulus. Central chemoreceptor dysfunctioning, demonstrated by an abnormal response to the CO₂ stimulus, is the most characteristic trait of this syndrome [2], but peripheral chemoreceptor deficiency, responsible for the ventilatory response to hypoxia, has also been observed in some cases. The syndromes of central alveolar hypoventilation and central apnoeas are not absolutely synonymous, even if the former can elicit the latter: central apnoeas have been observed in the absence of any daytime hypoventilation, and central hypoventilation syndrome is not necessarily accompanied by central apnoeas during sleep. Nor is central alveolar hypoventilation synonymous with obesity-hypoventilation syndrome (the current term for Pickwick’s syndrome) even though these conditions have several points in common. Central apnoea syndrome and obesity-hypoventilation syndrome are described in other chapters of the present volume.