Upper airway collapse during drug induced sleep endoscopy: head rotation in supine position compared with lateral head and trunk position.

Drug induced sedated sleep endoscopy (DISE) is often employed to determine the site, severity and pattern of obstruction in patients with sleep apnea. DISE is usually performed in supine position. We recently showed that the obstruction pattern is different when DISE is performed in lateral position. In this study, we compared the outcomes of DISE performed in supine position with head rotated, with the outcomes of DISE performed with head and trunk in lateral position. The Prospective study design was used in the present study. Sixty patients with OSA (44 male; mean apnea hypopnea index (AHI) 20.8 ± 17.5 events/h) underwent DISE under propofol sedation. Patients were placed in lateral position, and the upper airway collapse was evaluated. The patients were then placed in supine position with the head rotated to the right side. DISE outcomes were scored using the VOTE classification system. In lateral position, nine patients (15.0%) had a complete antero-posterior (A-P) collapse at the level of the velum, nine had a partial A-P collapse. During head rotation and trunk in supine position, at the level of the velum, four patients (6.7%) had a complete A-P collapse, while two patients (3.3%) had a partial A-P collapse. For all other sites, the patterns of collapse were not significantly different between head rotation and lateral position. During DISE, rotation of the head in supine position, and lateral head and trunk position present similar sites, severity and patterns of upper airway collapse, with the exception of collapse at the level of the velum. Here the severity of A-P collapse is less severe during head rotation than in lateral head and trunk position.