Background Otolaryngologists utilize drug-induced sleep endoscopy (DISE) to evaluate the anatomic location and pattern of upper airway collapse in patients with obstructive sleep apnea (OSA). The cardiovascular consequences of OSA are due to intermittent hypoxia and negative intrathoracic pressure swings, leading to sympathetic activation. It is challenging, however, to assess these physiologic pressure swings during natural sleep; therefore, we applied objective measures of airflow and respiratory effort during DISE to measure pharyngeal pressure changes. We hypothesized greater retroepiglottic pressure changes during respiratory events from DISE to correlate with reduced nocturnal blood pressure “dipping” during 24-hour ambulatory blood pressure monitoring (ABPM), thereby enhancing surgical management of OSA by linking intraoperative findings to cardiovascular outcomes.

Methods Patients with untreated OSA prospectively underwent ABPM and DISE with pharyngeal manometry. Retroepiglottic pressure (cm H2O) was calculated as the mean pressure differential for each obstructed breath between the start of inspiration and the nadir of negative pressure during inspiration. ABPM recorded blood pressure every 30 minutes while awake and hourly while asleep. Pearson’s correlation evaluated associations between retroepiglottic pressure changes and ABPM values.

Results Twenty patients were included for analysis. Patients, on average, were middle-aged (48.7±16.3 years), overweight (body-mass index BMI 29.5±3.46 kg/m2), male (65%), White (60%), with moderate-severe OSA at baseline (AHI 40.0±21.2 events/hour), normotensive (24-hour systolic & diastolic pressure 121±13.5 and 72.3±8.24 mmHg), and taking anti-hypertensive medications (45%). Correlational analysis showed greater retroepiglottic pressure swings were correlated with higher nocturnal, diurnal, and 24-hour ABPM values: 24-hour mean arterial pressure (MAP) (r=0.48, p=0.03), 24-hour systolic blood pressure (SBP) (r=0.46, p=0.04), higher 24-hour diastolic blood pressure (DBP) (r=0.39, p=0.09).

Conclusion In this study, a relationship between nocturnal blood pressure and retroepiglottic pressure swings during DISE was identified. These findings underscore the importance of intraoperative physiologic assessments in predicting cardiovascular risk in patients with OSA and highlight Otolaryngologists’ role in managing these risks. Future directions involve expanding the sample size and comparing these pharyngeal pressures against conventional polysomnographic OSA measures of cardiovascular risk.