Auto CPAP in the treatment of sleep apnea hypopnea syndrome.

Auto CPAP machines represent the most recent development in the field of CPAP therapy. We compared the efficiency of one of these machines (Morphée Plus, Pierre Medical, France) to conventional CPAP treatment in untreated SAHS. With this apparatus, the positive pressure level automatically varies within pressure bounds on each side of a reference pressure, these pressure characteristics being defined by the user. Sleep architecture, fragmentation, and nocturnal breathing abnormalities improved similarly in the two treatment groups as well as subjective and objective diurnal sleepiness. The number of hours that an effective pressure was applied during the 3 weeks of treatment was significantly greater in the auto CPAP group than in the conventional CPAP group. In a second study we asked if the efficiency of this auto CPAP machine would be affected by using an estimated value of the reference pressure based on body mass index, neck circumference, and AHI. Preliminary results demonstrate that the underestimation of the effective pressure given by the formula is adequately compensated by the machine. Auto CPAP may be an effective alternative to conventional CPAP and preliminary results suggest that the Morphée Plus apparatus may be used accurately without titration sleep study by estimating the reference pressure.