Interest of Treatment of Obstructive Sleep Apnea Syndrome by Constant CPAP and Auto CPAP (PREDIVARIUS)

Beneficial Effects of Obstructive Sleep Apnea Syndrome (OSAS) Treatment by Automatic Continuous Positive Airway Pressure (APAP) vs Constant Continuous Positive Airway Pressure (Constant CPAP) According to the Level of the Efficient Pressure and Its Variability. A Multicentric Randomized Trial

The investigators propose a multicentric controlled randomized trial whose goal is to evaluate the possibility of a prediction of the efficiency of APAP (automatic continuous positive airway pressure) and constant CPAP (constant positive airway pressure) in 800 severe obstructive sleep apnea syndrome (OSAS) patients according to their profile of pressure variability.

Multicenter open randomized clinical trial involving 800 patients with severe OSAS. After inclusion in the study, the patients will be proposed to initiate CPAP at home (ResMed S9 or PHILIPS PR1) using systematically an APAP mode between wide range of pressure variations (4 to 20 cm H2O) during the first 7day-period of time. After this first period of treatment, an analysis of the report will be released from the APAP in order evaluate the residual AHI, the duration of CPAP use and the amount of leaks in order to confirm CPAP efficiency and observance. Pressure parameters (efficient pressure and variability) will be collected. After randomization according to the further mode of ventilation to use (APAP vs constant CPAP), the patients will be treated at home for 3 months. In the constant CPAP group, efficient pressure will be determined as the P95 (ResMed) or the P90 (PHILIPS) as recommended by the manufacturers, while in the APAP group, the patients will be treated within the same range of pressure variations than during the first 7 day-period. Clinical and polygraphic evaluation will be done after 3 months of treatment, using the combined criteria previously described. In each group, results will be considered according to the efficient pressure value and its variability that were evaluated at the end of the first 7 day-period of treatment

A combined score that takes into account the residual apnea hypopnea index (AHI) under CPAP associated with the value of the Epworth score after 3 months of treatment.

The main objective of this study is to evaluate the ability to predict the mode of CPAP to use (APAP vs constant CPAP) in the treatment of OSAS patients, according to their own level of efficient pressure and its variability obtained on CPAP report after the first 7 days of use in an initial and systematic APAP mode. This prediction will be evaluated by using the association of the residual AHI value under CPAP and the Epworth score value obtained after 3 months of treatment, in each group of CPAP mode (constant vs APAP) used during the study. This combined criteria will be used according an ordinal scale with six levels of severity. It will be evaluated in each group (constant CPAP vs APAP) according to the level of P90 or P95 and the degree of pressure variability obtained during the first 7 day-period of use.

Inclusion Criteria: Adult patients > 18 with severe OSAS (AHI > 30/h) Patients naive of any previous OSAS treatment Written informed consent Exclusion Criteria: Patients with more than 20% of central events at the initial polygraphic recording previously treated by CPAP previously treated for OSAS by any surgical procedure involving upper airways < 18 with cardiac insufficiency with Chronic Obstructive Pulmonary Disease or obesity-hypoventilation syndrome without health insurance pregnant or lactating presumed uncooperativeness or legal incapacity