Autoadjusting CPAP therapy based on impedance efficacy, compliance and acceptance

Constant continuous positive airway pressure (CPAP) is the treatment of cho ice for the obstructive sleep apnea syndrome (OSAS). To enable the pressure to be matched more accurately to actual requirements, and thus increase pa tient acceptance, an autoadjusting device based on the measurement of upper airway impedance was developed (APAP(FOT)). We investigated the efficacy a nd compliance in continuous use at home. Fifty-two patients were treated (r andomized crossover) with CPAP and APAP(FOT) for 6 wk each. Respiratory dis turbances, sleep profile, and arousals improved significantly with both mod es (AHI: baseline, 35.1 +/- 26/h; APAP(FOT), 5.0 +/- 5.2; CPAP, 4.3 +/- 6.3 ; p < 0.001 baseline versus each mode). The mean pressure with APAP(FOT) wa s significantly reduced as compared with CPAP (CPAP, 7.8 <plus/minus> 7.5 c m H2O; APAP(FOT), 5.7 +/- 1.8 cm H2O; p < 0.001). Under APAP(FOT) the press ure was lower than that under CPAP for 81.5 <plus/minus> 21% of the time. A lthough overall use did not differ, 75% of the patients preferred APAP(FOT) for home treatment. We conclude that APAP(FOT) is as efficacious as consta nt CPAP in the treatment of OSAS. The treatment pressure can be reduced sig nificantly, and sleep microstructure improved with APAP(FOT). These might b e the reasons for patient preference of automatic therapy.