Depth-dependent changes of obstruction patterns under increasing sedation during drug-induced sedation endoscopy: results of a German monocentric clinical trial.

Purpose: Drug-induced sedation endoscopy (DISE) and simulated snoring (SimS) can locate the site of obstruction in patients with sleep-disordered breathing (SDB). There is clinical evidence for a change in collapsibility of the upper airway depending on the depth of sedation. So far, a dose-response relationship between sedation and collapsibility has not been demonstrated.
Methods: DISE and SimS were performed in 60 consecutive patients with SDB under monitoring of depth of sedation by BiSpectral Index® (BIS). Initially, SimS was conducted followed by DISE using bolus application of propofol. Sedation was performed up to a sedation level representing slow wave sleep (BIS = 40). The collapsibility of the upper airway was documented at decreasing sedation levels by an identical pictogram classification.
Results: For all levels and patterns of obstruction, a dose-dependent increase in the collapsibility of the upper airway was detected. A maximum collapsibility was achieved at sedation levels representing slow wave sleep. The collapsibility during SimS corresponded to light sleep stages and did not cover slow wave sleep.
Conclusion: A dose-dependent change of patterns of obstructions can be observed during DISE under BIS monitoring indicating sedation depth. The obtained patterns of obstruction during DISE and SimS should thus be interpreted with regard to the sedation depth.