Effects of Continuous Positive Airway Pressure on Middle Ear Pressure and Acoustic Stapedial Reflex

Abstract

Objective

This study investigated the effects of continuous positive airway pressure (CPAP) on middle ear pressure and acoustic stapedial reflex and the correlation between CPAP and middle ear pressure.

Study Design

Prospective cohort study.

Setting

Tertiary hospitals.

Subjects and Methods

Fifty patients with obstructive sleep apnea-hypopnea syndrome were assigned to the study group, and 50 healthy volunteers were assigned to the control group. The subjects underwent standard tympanometry while wearing a CPAP device (ie, simulated CPAP treatment), which was set to 0, 5, 10, and 15 cm H₂O, respectively. Tympanometry was performed before and after swallowing at each pressure of CPAP treatment.

Results

The mean middle ear pressures were 21.2, 22.6, 22.7, and 23.4 daPa (before swallowing) and 21.6, 42.6, 81.4, and 118.6 daPa (after swallowing) in the study group and 17.6, 18.7, 19.5, and 20.8 daPa (before swallowing) and 17.7, 44.2, 85.6, and 120.5 daPa (after swallowing) in the control group at the CPAPs of 0, 5, 10, and 15 cm H₂O, respectively. While the CPAPs were at 0 and 15 cm H₂O, the stapedial muscle reflex at 1.0 kHz did not have a significant difference between the 2 groups (χ² = 0.521, P = .470). The Pearson correlation coefficient of the CPAP pressure and the middle ear pressure after swallowing was 0.812 (P < .001).

Conclusion

CPAP affected middle ear pressure and was directly proportional to the pressure of the CPAP. However, CPAP treatment had no significant effect on stapedial muscle reflex.