[Computer-assisted nCPAP settings in comparison with conventional methods]

CPAP with constant pressure is the method of choice to treat obstructive sleep apnoea. To find the optimal pressure, automatic systems were developed, permitting computerised titration of pressure based on respiratory patterns. One important point in the algorithm of titrating pressure is the shape of the inspiratory breath flow-time relation. It can be used to detect early inspiratory obstruction. In the present study the results of automatic CPAP titration were compared with conventional constant CPAP. In 12 patients with obstructive sleep apnoea syndrome two polysomnographies were performed after diagnosis and conventional titration. In a randomised cross-over study the adequate constant CPAP was compared with computerised variation of pressure by Autoset-CPAP. During both methods apnoeas, hypopnoeas and snoring were reduced. In the autoset mode the number of apnoeas and hypopnoeas was 30.14 +/- 17.6/sleeping time, in the constant mode it was 7.9 +/- 11.2/sleeping time (p < 0.01). The number of episodes with snoring in the autoset mode was 18.7 +/- 21.8 and in the constant pressure mode 7.9 +/- 11.2 (p = 0.054). No difference could be detected in respect of sleeping time, sleep efficiency, arousals and sleep stages. We conclude that in patients accepting constant high pressures constant CPAP remains the method of choice. Automated CPAP offers an alternative in the case of pressure intolerance beneath BiLevel-CPAP.