Tonsillar hypertrophy in an adult with obesity-hypoventilation syndrome. The use of the flow-volume loop.

A 29-year-old obese man had marked tonsillar hypertrophy, somnolence, hypoxemia, and hypercapnia. Endotracheal intubation followed by tracheostomy relieved the hypoventilation. Weight loss improved the arterial blood gas levels. Sequential upright and supine flow-volume loops were compatible with a fixed upper-airway obstruction (such as would occur) with enlarged tonsils) prior to tonsillectomy. Following surgery, the expiratory flow-volume curve was abnormal in the supine position, consistent with the additional diagnosis of posterior pharyngeal hypotonia. Thus, in this patient the unique combination of tonsillar hypertrophy, posterior pharyngeal hypotonia, obesity, and a depressed respiratory center led to retention of carbon dioxide.