The effect of continuous positive airway pressure on middle ear pressure

Objectives/hypothesis: To investigate the effect of continuous positive airway pressure (CPAP) on middle ear pressure in patients with obstructive sleep apnea syndrome (OSAS).

Study design: Prospective clinical case-control study.

Methods: Seventy-eight patients with moderate and severe OSAS (the mean apnea-hypopnea indexes were 22.70 ± 3.59 and 48.59 ± 12.50, respectively) using CPAP (study group) and 60 patients with no sleep apnea syndrome (control group) were included in the study. Forty-two of the patients were female and 96 were male. The mean age in the study group was 47.38 ± 6.23, whereas it was 46.10 ± 11.96 in the control group (P > .05). The middle ear pressure of all study subjects was evaluated with tympanometry at the beginning of the study and 6 months later. Tympanometric measurements of both groups were compared. Furthermore, the same data for the study group were also evaluated according to CPAP pressure levels.

Results: The middle ear peak pressure values of the patients in the study group were significantly increased from -63.04 ± 55.82 daPa to -39.6 ± 27.72 daPa after 6 months (P < .01). The middle ear pressure in the control group was found to be -13.26 ± 22.60 daPa at the beginning of the study and -13.60 ± 38.82 daPa after 6 months (P > .05). The mean middle ear pressure level was significantly higher in patients using CPAP at 12 to 14 cm H2 O pressure than in those using CPAP at 8 to 10 cm H2 O pressure (P < .05).

Conclusions: There was a significant increase in the middle ear pressure of patients using CPAP regularly for 6 months. This increase was proportional to the pressure level of the CPAP device.

Level of evidence: 3b.