Effect of Expiratory Pressure Relief During Continuous Positive Airway Pressure Therapy on Adherence in a Retrospective Analysis of Recent Clinical Experience

Mohan K
Sleep Disorder Center, JWM Neurology/St Vincent Sleep Disorder Center
Indianapolis, IN

Introduction

Many factors may influence compliance and adherence to continuous positive airway pressure therapy. Pressure relief during exhalation may offer additional comfort and provide a compliance advantage. The recent introduction of C-Flex® offers such relief. A retrospective analysis of device download data in a clinical setting may offer insight into the effect of this enhanced therapy.

Methods

A retrospective analysis of therapy compliance data was performed with Institutional Review Board approval. Subjects were selected from a sequential series of clinical sleep laboratory patients. Patients were diagnosed and titrated in the sleep laboratory using full polysomnography, employing AASM standard methodology. Both conventional CPAP (CPAP) and CPAP with flexible pressure relief (FLEX) were used in recent clinical practice. Both modes of therapy were implemented on the same CPAP device (REMStar Pro, Respironics, Inc., Murrysville , PA , USA ).

Heated humidification was available to all patients and was used by most. All patients received standardized training on equipment and mask fitting. Patients routinely provided compliance data as part of a structured follow program at the Sleep Disorders Center . Data were stored on a SmartCard, and downloaded into Encore Pro Compliance software for archiving, reporting and analysis. Average number of hours of use and number of days of use were recorded for each patient. Patients were said to have a compliant night if they slept more than 4 hours during the night.

Percentage of Compliant nights is reported for each subject. Summary data were generated by the compliance software, with subsequent appropriate statistical analysis performed. Descriptive statistics are reported. Two-tailed comparison between therapies were performed using either t-test (if normal distribution) or Wilcoxon Signed Rank. Data are reported mean ± standard deviation.

Results

A total of 96 subjects (75 FLEX, 21 CPAP) were included in the analysis. CPAP patients were on therapy a longer period than FLEX patients (293 ± 291 days CPAP vs. 49 ± 42 days C-Flex, p<0.001). Average hours of use per night was significantly longer for patients on FLEX v. CPAP therapy (5.06 ± 1.80 hours v. 3.96 ± 2.63 hours respectively, p=0.029). FLEX demonstrated a significantly higher number of compliant nights (68.0 ± 28.0 % v. 51.6 ± 34 %, respectively, p=0.025).

Conclusion

Review of recent clinical therapy experience suggests a compliance advantage for the C-Flex v. CPAP mode in a general clinical sleep medicine practice.

This research was supported by a grant from Respironics, Inc.

From SLEEP, Volume 27, Abstract Supplement, 2004