The Relationship of Therapeutic Positive Airway Pressure and Upper Airway Collapsibility During Drug-Induced Sleep Endoscopy.

OBJECTIVE: Drug-Induced Sleep Endoscopy with Positive Airway Pressure (DISE-PAP) provides quantitative evaluation of upper airway collapsibility, known as pharyngeal opening pressure (PhOP). Limited research exists on the relationship between PhOP and therapeutic continuous positive airway pressure (CPAP). This study investigated the relationship between therapeutic CPAP level and PhOP. STUDY DESIGN: Retrospective cohort study. SETTING: Single academic teaching hospital. METHODS: This study evaluated adults ≥18 years with obstructive sleep apnea (AHI ≥ 5) who underwent DISE-PAP from 2022 to 2024, had >2 h/d average PAP use, and well-controlled OSA on PAP. Primary outcome was the relationship between median CPAP level (mCPAP), CPAP level at 95% of time (t95CPAP), and PhOP. Secondary outcomes determined relationships between mCPAP, t95CPAP, and PhOP with AHI and BMI. RESULTS: Ninety-four patients were included (age 50.5 ± 15.1 years, BMI 29.9 ± 4.4 kg/m2, AHI 35.3 ± 23.3 events/h). Mean PhOP was 7.1 ± 2.9 cmH2O, mCPAP 8.5 ± 2.4 cmH2O, and t95CPAP 10.3 ± 2.5 cmH2O. Positive correlation existed between PhOP and mCPAP. PhOP was 1.5 and 3.3 cmH2O lower than mCPAP and t95CPAP, respectively. As mCPAP and t95CPAP increased by 1 unit, PhOP increased by 0.33 and 0.36 cmH2O. BMI and AHI were mildly correlated with mCPAP; for each 10-point increase in AHI, mCPAP and PhOP increased by 0.4 and 0.3 cmH2O, respectively. However, the association between AHI and PhOP did not reach statistical significance. CONCLUSION: Positive correlation exists between mCPAP, t95CPAP, and PhOP, with PhOP lower than therapeutic CPAP levels. These findings may allow surgeons to use therapeutic CPAP levels when DISE-PAP is unavailable to estimate upper airway collapsibility and determine surgical interventions. LEVEL OF EVIDENCE: Level 4.