EVALUATION OF AN AUTO-CPAP DEVICE FOR TREATMENT OF OBSTRUCTIVE SLEEP-APNEA

Background-Auto-CPAP machines used in the treatment of obstructive sle ep apnoea (OSA) are designed to vary the treatment pressure automatica lly in order always to apply the actually needed pressure. Consequentl y they should be able to achieve at least identical therapeutic effect s as conventional constant pressure CPAP with a lower mean treatment p ressure. The present study was designed to evaluate the therapeutic ef ficacy and the treatment pressure of an auto-CPAP machine (REM+auto(R) , SEFAM) in comparison with a conventional CPAP device. Methods-Follow ing CPAP titration, 16 patients with OSA were allocated to receive con ventional CPAP and auto-CPAP treatment under polysomnographic control in a randomised order. After each treatment the patients were asked, t o assess the therapy using a questionnaire; a vigilance test was also carried out and subjective daytime sleepiness was evaluated using the Epworth Sleepiness Scale (ESS). Results-The mean (SD) apnoea/ hypopnoe a index (AHI) during auto-CPAP treatment was comparable with that duri ng conventional CPAP treatment (4.2 (5.1) versus 3.6 (4.0)). Neither a n analysis of sleep architecture nor the arousal index (7.4 (4.1) vers us 7.0 (4.3)) revealed any significant differences. Daytime sleepiness measured with the ESS was also comparable (5.3 (3.4) versus 6.5 (4.2) ). The vigilance test showed normal values after both treatments in al l patients with no significant differences. The mean pressure during a uto-CPAP treatment (8.1 (2.9) mbar), however, was significantly higher than that employed in conventional CPAP treatment (7.6 (2.7) mbar; me an difference 0.5 mbar; 95% CI 0.1 to 0.9 mbar; p<0.05). Conclusions-A uto-CPAP was equally as effective as conventional CPAP with respect to therapeutic efficacy. The aim of reducing the treatment pressure with auto-CPAP, however, was not achieved.