Prospective randomized comparison of impedance-controlled auto-continuous positive airway pressure (APAP(FOT)) with...

Background: The measurement of impedance permits reliable detection of obstructive apneas, hypopneas and upper airways resistance syndrome.Objective: To establish whether impedance-controlled self-adjusting positive airway pressure therapy (APAP(FOT)) is equally as good as constant continuous positive airway pressure (CPAP) in the treatment of sleep apnea syndrome (OSAS).Methods: Twenty men and five women with OSAS (age 52.8+/-9.0 years, body mass index (BMI) 31.4+/-5.0 kg/m(2), AHI 32.2+/-18.1/h (mean+/-SD)) underwent baseline polysomnography, manual CPAP titration and two nights of treatment, one with APAP(FOT), one with constant CPAP.Results: With both modes, a significant reduction in respiratory disturbances was seen (apnea/hypopnea index (AHI) baseline 32.2+/-18.1/h, constant CPAP 6.6+/-8.7, APAP(FOT) 5.5+/-3.8/h, P<0.001 baseline vs. each treatment mode). Under APAP(FOT), the sleep profile was normalized (S3/4 baseline 16.3+/-13.9% total sleep time (TST), APAP(FOT) 21.6+/-10.9% TST, P<0.05, rapid eye movement (REM) 14.2+/-6.7% TST vs. 20.3+/-7.3% TST, P<0.01), while with constant CPAP, a tendency towards improvement was found. The mean treatment pressure with APAP(FOT) was significantly lower than the constant CPAP (5.7+/-2.1 vs. 8.3+/-1.6 mbar, P<0.001).Conclusion: We conclude that APAP(FOT) is at least as effective as constant CPAP in normalizing sleep and breathing in OSAS.