Impairment of Upper Airway Patency and CPAP Effectiveness During OSA Treatment With Expiratory Pressure Alleviation:...

Expiratory pressure alleviation (EPA) algorithms have been incorporated into CPAP devices to reduce expiratory discomfort during treatment of OSA. Because pharyngeal narrowing or collapse can occur during expiration, EPA may impair upper airway patency.

Does EPA compromise upper airway patency and CPAP efficacy in patients with severe OSA?

Adults with severe OSA using nasal CPAP were considered to participate. The study was conducted in 4 steps. Steps 1 and 2 were performed during a single overnight polysomnography study. In step 1, peak inspiratory flow (PIF) was measured during inspiratory flow limitation with and without EPA. In step 2, CPAP titration was performed in randomized order with and without EPA. Steps 3 and 4 were conducted at home. Residual apnea-hypopnea index (AHI) and adherence were compared with and without EPA activation during fixed (step 3) and auto-CPAP (step 4).

Twenty-nine patients were studied (55% female; mean age ± SD, 63 ± 12 years; mean BMI ± SD, 37 ± 7 kg/m²; AHI, 58 events/h; 39-83). EPA activation reduced PIF compared with no EPA (0.38; 0.34-0.42 vs 0.19; 0.15-0.23 L/s, respectively; P < .001). The manually titrated CPAP level was higher with EPA than without EPA (11.40 ± 1.95 vs 9.17 ± 1.78 cm H₂O, respectively; P < .001). The residual AHI was higher with EPA than without EPA during fixed (3.7 ± 2.2 vs 1.3 ± 0.6 events/h) and automatic CPAP (1.4; 0.6-2.1 vs 0.8; 0.5-1.8 events/h, respectively; P < .05). No significant change in CPAP adherence was observed during fixed (7.0 ± 0.8 vs 7.2 ± 1.0 hours) and automatic CPAP (7.0 ± 1.3 vs 6.9 ± 1.3 hours), with (P = .497) and without (P = .506) EPA, respectively.

Our results show that EPA application compromised upper airway patency and required higher therapeutic CPAP than without EPA. EPA also impaired OSA control but did not impact CPAP adherence.

ClinicalTrials.gov; No.: NCT05219591; URL: www.

gov.