Comparison of automatic and continuous positive airway pressure in a night-by-night analysis: a randomized, crossover study.

BACKGROUND: Long-term compliance is suboptimal in the treatment of the obstructive sleep apnea syndrome (OSAS).

OBJECTIVES: We compared the efficacy of and the adherence to automatic continuous positive airway pressure (APAP) and constant continuous positive airway pressure (CPAP) based on a night-by-night analysis.

METHODS: We performed a randomized, single-blind crossover study in 20 patients with moderate-to-severe OSAS. After diagnostic polysomnography and manual titration, patients were treated for 8 weeks with both constant CPAP and APAP in random order. Compliance and leakage were analyzed night by night using the software LOGSoft of the Magellan iPAP device.

RESULTS: The reduction in the apnea/hypopnea index (baseline 32.9 +/- 19.1/h, CPAP 4.6 +/- 2.9/h, APAP 5.6 +/- 3.6/h; p < 0.001 compared to baseline) and the Epworth Sleepiness Scale (baseline 10.3 +/- 5.7, CPAP 6.6 +/- 4.8, APAP 4.9 +/- 4.6; p < 0.001 compared to baseline) did not significantly differ between the treatment modes. Leakage time and compliance per night were not statistically different (leakage CPAP 31 +/- 57 min, APAP 25 +/- 49 min; compliance CPAP 383 +/- 116 min, APAP 382 +/- 107 min). There was no correlation between leakage and compliance. Thirteen patients (65%) preferred APAP at the end of the study.

CONCLUSIONS: Treatment efficacy and adherence are similar with CPAP and APAP. There is a trend towards lower leakage with APAP therapy. Patients prefer the automatic mode to fixed pressure.