The Effect of CPAP on Middle Ear Pressure

Abstract

Objective: While continuous positive airway pressure (CPAP) is commonly used for obstructive sleep apnea treatment, its effect on middle ear pressure is unknown. The purpose of this study is to measure the effect of CPAP on middle ear pressure and describe the correlation between CPAP levels and middle ear pressures.

Method: This is a prospective cohort study conducted in January, 2011. 10 volunteers with no known history of Eustachian tube dysfunction or obstructive sleep apnea had standard tympanometry measurements while wearing a CPAP device. Measurements were taken at baseline and with CPAP air pressures of 5, 10, and 15 cm H20.

Results: Prior to a swallowing maneuver to open the Eustachian tube, average middle ear pressures were 21.67 daPA, 22.63 daPA, 20.42, daPA, and 21.58 daPA with CPAP pressures of 0, 5, 10, and 15cm of H20, respectively. After swallowing, average middle ear air pressures were 18.83 daPa, 46.75 daPa, 82.17 daPa, and 129.17 daPa with CPAP pressures of 0, 5, 10, and 15cm of H20, respectively. The post-swallow Pearson Correlation Coefficient correlating CPAP and middle ear pressures was 0.783 (P < .001).

Conclusion: Middle ear air pressure is directly proportional to CPAP air pressure in subjects with normal Eustachian tube function. While further investigation is necessary, there may be otologic implications for patients who are chronically CPAP dependant. These findings may also influence the perioperative practice of otologic and skull base surgeons.