Ambulatory CPAP Titration in Moderate Obstructive Sleep Apnea (ATMOS)

The aim of this trial is to compare two different ways of CPAP titration: CAP titration with fixed pressure vs. auto-titrating CPAP.

Continuous positive airway pressure (CPAP) for the treatment of moderate obstructive sleep apnea (OSA) is only reimbursed in Belgium after in-laboratory overnight titration. Nevertheless, in a recent clinical practice guideline of the AASM, it is recommended that PAP therapy can be initiated using either in-laboratory titration or auto-titrating CPAP (APAP) at home in OSA patients without significant comorbidities. Indeed, several studies evaluated the impact of titration with APAP at home in these patients and showed that the outcome is comparable with in-hospital titration. Up to now, evidence for home titration with fixed CPAP (and follow-up via telemonitoring) is very limited. The use of sleep laboratory space is costly and limits access for diagnostic studies. This study aims to evaluate whether CPAP titration at home with fixed CPAP produces outcomes equal to those following APAP titration.

Patients will start CPAP treatment with a pressure that is calculated by the following formula (predicted pressure = (0.13 x BMI) + (0.16x neck circumference in cm) + (0.04 x AHI)) with a maximal pressure of 10 cmH2O. After 3 nights and after 7 nights, CPAP data will be remotely evaluated and pressure will be adapted based on the following rules: After 3 nights: median obstructive AHI<5/h: decrease pressure with 2 cmH2O; median obstructive AHI>5/h: increase with 2cmH2O After 7 nights: median obstructive AHI>5/h of 4 nights after last adaptation: increase with 2 cmH2O

Patients will start CPAP treatment with an auto-adjusting CPAP device with pressure levels between 4 and 12 cmH2O. After 7 nights of titration, the optimal pressure will be determined by analyzing the median of the nightly pressure that included 95% of the periods (percentile 95). CPAP treatment will be continued with this fixed optimal pressure.

Inclusion Criteria: moderate OSA (obstructive AHI 15-30/u on initial PSG) Exclusion Criteria: Presence of hypoventilation Presence of central sleep apnea (central AHI ≥ 15)