Long-term efficacy of fixed CPAP recommended by Autoset (R) for OSAS

The Autoset(R) autotitration system (Resmed, Australia) was designed as an aid for determination of the effective level of CPAP. Two studies have show n that the 95% pressure centile during a night with Autoset(R), after exclu ding any periods with severe leak (P95), was well correlated with the press ure determined manually according to the reference method. However, the sui tability of P95 under Autoset(R) for treatment with conventional CPAP neede d to be evaluated outside of the context of titration. The objective of thi s study was to measure the compliance and efficacy of CPAP at P95 determine d by Autoset(R), after 3 months. Twenty-four patients who had undergone rou tine autotitration by Autoset(R) under polysomnographic control in the labo ratory for previously untreated OSAS were evaluated after 3 months of treat ment with CPAP at P95. This evaluation was based on compliance, daily usage , determined by reading the hourly counter, Epworth sleepiness score and ho me respiratory recording under CPAP. Polysomnography under Autoset(R) showe d a significant reduction of abnormal respiratory events (apnea-hypopnea in dex (AHI): 5.7 (+/-4.6) vs 69.6 (+/-29.8) n/h; p<0.001). P95 was between 8. 5 and 15 cm H2O (mean: 11.2 (+/-1.6)). Two patients were lost to followup. At 3 months, 18 out of 22 (82%) patients declared that they were still usin g their machine with a daily usage of 5.25 (+/-1.82) h. The Epworth sleepin ess scale was significantly decreased (5 (+/-4.1) vs 11.4 (+/-5.4); p<0.05) . P95 recommended by Autoset(R) remained effective on abnormal respiratory events with a low AHI (4.1 (+/-3.2)n/h) and a low 4% oxygen desaturation in dex (3.6 (+/-4.5) n/h) under CPAP. This study confirms the efficacy of autotitration and the suitability of P9 5 determined by Autoset(R) for long-term treatment by conventional CPAP at home.