Upper airway collapsibility in habitual snorers and sleep apneics: Evaluation with drug-induced sleep endoscopy

Increased upper airway collapsibility has been suspected of being involved in the pathogenesis of sleep-related diseases. It is assumed that patients with severe obstructive sleep apnea syndrome (OSAS) show a stronger collaps e of the upper airway compared with habitual snorers. It was the objective of this study to analyze the patterns of upper airway collapse in habitual snorers and patients with OSAS and to correlate these results with data fro m polysomnography. Endoscopy was carried out during drug-induced sleep (wit h propofol) and collapsibility was analyzed at two major levels (palatal an d tongue base). A total of 207 habitual snorers and 117 patients with OSAS underwent endoscopy after overnight polysomnography in our sleep laboratory . In 95% of cases we were able to induce snoring during drug-induced sleep. The collapsibility in the area of the base of the tongue correlated with h igher values of the respiratory disturbance index (RDI) as recorded by stan dard polysomnography. Patients with OSAS showed significantly stronger coll apsibility compared with snorers. The difference was more evident at the to ngue-bass level. We found no significant correlation between the applied CP AP pressure and collapsibility in patients with OSAS. These results show th at collapsibility at the tongue-base level is a factor relevant in sleep-re lated breathing disorders.