Drug-induced sleep endoscopy and simulated snoring in patients with sleep-disordered breathing: agreement of anatomic changes in the upper airway.

Drug-induced sleep endoscopy (DISE) and simulated snoring (SimS) are performed as part of the diagnostic procedure in patients with suspected sleep-disordered breathing (SDB). Despite both techniques frequently performed, they have rarely been evaluated yet in terms of agreement of the obtained results. Both diagnostic procedures were performed consecutively in 40 patients with SDB and documented identically. The obtained data were analysed with respect to the agreement of both procedure at different levels of the oropharynx as well as different patterns of obstruction and vibration. The anterior-posterior collapsibility of the soft palate/uvula revealed a moderate agreement between SimS and DISE (κ = 0.42; 95 % CI 0.22-0.63). The dorsal shift of the tongue base agreed moderate for patients with an AHI below 10 (κ = 0.47) and above 25 (κ = 0.44) between SimS ad DISE. The lateral and circular pharyngeal collapsibility at velum and tongue base level did not agree between SimS and DISE, was higher for DISE and could be partially reversed by mandibular protrusion. Collapse patterns of the soft palate and uvula can be induced by SimS and resemble the patterns induced by DISE. The dorsalization of the tongue base can be simulated to a lower extent by SimS. Lateral and circular patterns of collapse at the upper and lower oropharynx induced by DISE do not seem to be simulated by SimS. SimS seems to be an additional method to screen the collapsibility of the soft palate and uvula prior to DISE.