The Pickwickian Syndrome: Part of a Spectrum of Disordered Ventilatory Control

A 29-year-old man 71 inches tall, who had weighed about 290 pounds for ten years or more, fell asleep when not stimulated, showing cyanosis, irregular respiration, loud snoring, and twitching and jerking. Forced vital capacity was 65 per cent of predicted. Arterial blood gases showed that the patient developed severe hypoxemia and acute respiratory acidosis upon falling asleep but could reverse both and produce marked respiratory alkalosis with voluntary hyperventilation. This man was typical of persons with the Pickwickian syndrome, who characteristically are obese, plethoric, and somnolent. Besides the signs and symptoms mentioned above, they exhibit polycythemia, right ventricular hypertrophy, and right ventricular failure. Except for obesity, these are thought to result from chronic hypoventilation. The etiology of the latter remains unclear, as the great majority of obese persons do not hypoventilate and do not become Pickwickians. Recent studies of ventilatory response to hypoxia and hypercapnia suggest deranged central control mechanisms as an important feature, if not the underlying defect, in this disease. The Pickwickian syndrome is serious and life-threatening. If upper-airway obstruction is a feature, tracheostomy may control the problem. Otherwise the only treatment until recently has been massive weight-reduction, which has usually been extremely difficult to achieve. However, the hormone progesterone has recently been tried as a respiratory stimulant, with encouraging results, and may be useful in the Pickwickian syn-drome and other hypoventilation syndromes.