Pressure reduction during exhalation in sleep apnea patients treated by continuous positive airway pressure

This French, multicenter, randomized double-blind controlled trial tested the hypothesis that pressure reduction during exhalation (C-Flex; Respironics; Murrysville, PA) would improve continuous positive airway pressure (CPAP) compliance, comfort, and quality of life.

Two hundred eighteen newly diagnosed sleep apnea patients (seven centers; mean [+/- SD] age, 55 +/- 11 years; mean body mass index, 31 +/- 6 kg/m(2); mean apnea-hypopnea index, 44 +/- 21 events/h) were randomly assigned to receive 3 months of treatment with CPAP (108 patients) or C-Flex (110 patients). Objective compliance, generic quality-of-life questionnaire (SF-36) scores, disease-specific quality-of-life questionnaire (Grenoble Sleep Apnea Quality of Life [GrenobleSAQOL]) scores, and visual analog scales for CPAP comfort and side effects were determined at baseline and after 3 months. After 3 months, patients in the CPAP arm were moved to the C-Flex arm for 3 additional months (open study).

An intention-to-treat analysis demonstrated that there were no differences at 3 months between C-Flex and CPAP use in terms of compliance, the rate of side effects, and comfort. Low compliers receiving CPAP therapy (< 4 h of use) significantly improved this outcome during the open study (p = 0.04). There was a significant improvement in six of eight of the SF-36 domain scores and in all of the domains of the GrenobleSAQOL scores in both groups using either CPAP or C-Flex.

In unselected sleep apnea patients, C-Flex was associated with similar outcomes to standard CPAP. Low compliers receiving CPAP therapy improved their adherence when moving to C-Flex.

ISRCTN Register Identifier: 08065291.