Auto-CPAP therapy based on the forced oscillation technique.

Autoadjusting CPAP devices (APAP) are designed to continuously adjust the positive pressure to the required levels, and thus increase treatment quality and patient compliance. The results of APAP treatment strongly depend on the control mechanism of the respective APAP device. In agreement with other working groups, we have recently shown that the forced oscillation technique (FOT) is capable of detecting incipient upper airway obstruction prior to physiological reactions such as the onset of increasing esophageal pressure swings or microarousals. Therefore we studied efficacy and acceptance of a novel APAP device controlled exclusively by FOT. 100 consecutive patients with OSAS confirmed by polysomnography (mean AHI 47.9 +/- 22.6) and daytime sleepiness (Epworth sleepiness scale, ESS 12.6 +/- 3.9) were randomized to either APAP treatment (n = 50) or conventional CPAP treatment (n = 50). Polysomnographies were performed at the second treatment night and subjective sleepiness (modified ESS) was established in the morning. The respiratory disturbance was largely normalized in both treatment groups in the second treatment night (AHI 4.7 +/- 5.3 vs. 3.7 +/- 3.4; n.s.). Both groups showed largely improved sleep profiles and had markedly reduced ESS-scores (6.6 +/- 3.6 vs. 7.0 +/- 3.4; n.s.). The mean treatment pressure during APAP was significantly lower than during CPAP treatment (6.0 +/- 2.0 vs. 9.0 +/- 1.8 mbar; p < 0.001). There were no significant differences between APAP and CPAP treatment in any parameter of efficacy or acceptance. APAP treatment with this device controlled exclusively by FOT is well accepted by the patients and permits an adequate treatment of OSAS without the need for invidiual CPAP titration.