A Long-term Randomized, Cross-over Comparison of Auto-titrating and Standard Nasal Continuous Airway Pressure

This study is a 12-week randomized, cross-over, single-blind comparison of the tolerance, compliance, and symptomatic improvement obtained with standard nasal continuous positive airway pressure (CPAP) vs. an auto-titrating, self-adjusting device (APAP). Sixty newly diagnosed patients, 53 with obstructive sleep apnea (OSA) and seven with upper airway resistance syndrome were studied. Thirty-nine patients (65%) completed the 24-week protocol. Data were complete in 33. In these 33 patients CPAP and APAP reduced the Epworth Sleepiness score from 15+/-1 (+/-SEM) to 8+/-1 and 9+/-1 respectively (both <0.0001 from baseline but NS between modes). The APAP average pressure was lower than the CPAP pressure, 6.4+/-0.4 and 10.6+/-0.4 cm H20, respectively. The average daily machine use was greater with APAP, 6.0+/-0.3 hrs. versus 5.5+/-0.3 hrs. with CPAP (P < 0.04). The number of days of machine use, and the pattern of use were not different between CPAP and APAP. A higher proportion of patients who did not complete the study was randomized to CPAP for their initial treatment period. This study showed that: 1) CPAP and APAP produced an equivalent improvement in daytime sleepiness, 2) APAP pressure was lower than CPAP pressure, 3) patients wore the APAP device longer during nights they used the pressure support system, and 4) patients who began the study with APAP were more prone to continue treatment. We conclude that APAP was better tolerated and used a greater number of hours than CPAP, but the extent of improvement in excessive daytime sleepiness was similar between the two modes of therapy.