The effect of head of bed elevation on upper airway collapsibility during drug-induced sleep endoscopy

Study Objectives: Drug-induced sleep endoscopy with positive airway pressure evaluates the collapsibility of the upper airway. It is currently unknown whether body position affects this assessment. We sought to determine whether the collapsibility of the airway may change with head of bed elevation. Methods: A prospective, consecutive cohort study was performed by 2 sleep surgeons at a tertiary care center. Inclusion criteria included adults 18 years of age and older with obstructive sleep apnea who were intolerant to continuous positive airway pressure therapy. Patients underwent drug-induced sleep endoscopy with positive airway pressure to evaluate them for alternative treatment options. Patients were evaluated in supine position with the head of bed both level and elevated to 30(degrees). The airway was evaluated using the standardized VOTE scoring system in both positions. Results: The 61 patients included in the study were predominantly male (70.5%), middle-aged (51.2 years), and obese (body mass index, 30.2 kg/m(2)) with moderate-to-severe obstructive sleep apnea (apnea-hypopnea index, 34.1 events/h). The cohort consisted of predominantly positional obstructive sleep apnea (mean supine apnea-hypopnea index 48.7 events/h, nonsupine apnea-hypopnea index 20.8 events/h). All 4 sites of the upper airway demonstrated a significant decrease in airway opening pressures with the head of bed elevated compared to level (P < .01 for all sites). There was no significant difference in VOTE scoring between level and upright positions. Conclusions: Patients with the head of bed elevated to 30 degrees have a significantly lower degree of airway collapsibility compared to patients in the level position but no significant change in VOTE scoring was observed.