This study aimed to evaluate the difference of upper airway collapse between the back-up head-elevated position (a 45° upward inclination) and supine position to better elucidate the role of back-up head-elevated position in reductions of obstructive sleep apnea (OSA) severity.
From August 2016 to May 2019, 198 patients aged between 18 and 70 years were recruited in this study prospectively. Drug-induced sleep endoscopy (DISE) findings were recorded with the patients first placed in the supine position then into the back-up head-elevated position with a 45° upward inclination.
From the supine to back-up head-elevated position, a significant decrease in the severity of collapse was observed in velum anteroposterior collapse and velum concentric collapse (p < 0.001 and p < 0.001, respectively), which was more predominant in patients with mild OSA than in patients with moderate to severe OSA. On the other hand, there was no significant improvement of any other collapse at the level of oropharynx, tongue base, or epiglottis when the position was shifted from the supine into back-up head-elevated position.
The back-up head-elevated position with a 45° upward inclination improved upper airway obstruction during DISE in velum anteroposterior collapse and velum concentric collapse. The proportion of patients with amelioration of upper airway collapse was much higher in patients with mild OSA than in patients with moderate to severe OSA. The back-up head-elevated position may be a reasonable alternative to traditional positional therapy for certain subgroups of patients with OSA.