An auto-continuous positive airway pressure device controlled exclusively by the forced oscillation technique

The forced oscillation technique (FOT) has been demonstrated to be a very s ensitive tool for the assessment of upper airway obstruction during nasal c ontinuous positive airway pressure (CPAP) therapy for obstructive sleep apn oea (OSA). The present study was designed to evaluate the therapeutic effic acy of a novel auto-CPAP device based exclusively on the FOT. Following manual CPAP titration, 18 patients with OSA (mean apnoea/hypopnoe a index (AHI) 48.0+/-28.1) were allocated to conventional CPAP and auto-CPA P treatment under polysomnographic control in randomized order. The patient s mere asked to assess their subjective daytime sleepiness using the Epwort h Sleepiness Scale (ESS). The mean AHI during auto-CPAP treatment was 3.4+/-3.4 and was comparable wi th that obtained during conventional CPAP treatment (4.2+/-3.6). The analys is of sleep architecture, the arousal index (6.6+/-2.1 versus 7.3+/-4.4) or the ESS (5.6+/-1.8 versus 7.3+/-4.4) did not reveal any significant differ ences. However, the mean CPAP pressure during auto-CPAP treatment (0.84+/-0 .26 kPa) and in particular the pressure applied in the lateral body positio n (0.74+/-0.35 kPa), was significantly lower than that employed in conventi onal CPAP treatment (0.93+/-0.16 kPa, both comparisons: p<0.05). The auto-continuous positive airway pressure device proved equally as effec tive as conventional continuous positive airway pressure. However, the mean treatment pressure was significantly reduced, especially when patients wer e sleeping in the lateral position.