Abstract
Introduction: Positive airway pressure in subjects with both obstructive sleep apnea and COPD reduces the risk of pulmonary hypertension, death and hospitalizations from COPD exacerbations, but adherence to the intervention is low, similar to the experience with noninvasive ventilation in stable COPD. We sought to assess whether hyperinflation on chest radiographs contributes to low adherence to positive airway pressure therapy in the overlap syndrome.
Methods: Records of subjects with a listed diagnosis of COPD at the time of polysomnography were reviewed. Overlap syndrome was diagnosed when COPD was clinically confirmed with spirometry showing a fixed airway obstruction, and when the apnea hypopnea index was ≥5. Hyperinflation was evaluated by a review of the right diaphragm height on a lateral chest radiograph. Adherence was assessed clinically or through device download at a 3 month follow-up, and later adherence was assessed by phone contact. A receiver operating curve was used to determine whether diaphragm height was associated with adherence.
Results: 21 of 41 subjects (51%) were considered adherent to positive airway pressure therapy at the 3 month visit. Adherent subjects were more overweight compared to non-adherent subjects (body mass index BMI 36.0 ± 5.7 vs. 32.0 ± 5.7 kg/m2, p = 0.03), sleepier at the onset (Epworth 13.0 ± 5.8 vs. 9.4 ± 5.4, p < 0.05) and less likely to have hyperinflation as defined by a right diaphragm height ≤2.45 cm (33% vs. 65%, p = 0.04). The BMI and initial sleepiness no longer predicted adherence beyond three months, but 35% of subjects with a right diaphragmatic height ≤2.45 cm were adherent beyond 3 months, compared to 75% of those a right diaphragmatic height >2.45 cm (Fisher's exact test p=0.04).
Conclusion: Hyperinflation is associated with decreased adherence to positive airway pressure therapy in the overlap syndrome.
- Obstructive Sleep Apnea
- Chronic Obstructive Pulmonary Disease
- Airway Obstruction
- Continuous Positive Airway Pressure
- Patient Compliance
- Positive-Pressure respiration
Footnotes
- ↵3Corresponding author: Sleep Disorders Center/Neurological Institute and Pulmonary, Allergy, and Critical Care Medicine/Respiratory Institute Cleveland Clinic, A-90 9500 Euclid Avenue Cleveland, OH 44195 e-mail: aboussl{at}ccf.org Tel: 216-444-0420 Fax: 216-445-8160
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