Awake upper airway collapsibility is related to airway collapsibility during sleep (Pcrit) in obstructive sleep apnoea

Introduction: An anatomically narrow or highly collapsible upper airway is the main cause of obstructive sleep apnoea (OSA). However, the extent of upper airway anatomical impairment varies widely between patients. This is important as patients with highly collapsible airways likely require different therapy (e.g. CPAP) to those who only have modestly collapsible airways (e.g. a dental device). The critical closing pressure (Pcrit) technique is the gold standard method used to quantify upper airway collapsibility. However, it is not feasible for routine clinical use as it requires detailed overnight measurements by a skilled sleep researcher. Thus, development of a simple tool to measure upper airway collapsibility is required to move beyond the current trial and error approach for the treatment of OSA. Accordingly, this study aims to determine if a simple wakefulness assessment is related to Pcrit during sleep.