Effect of positive airway pressure (PAP) therapy in patients with excessive dynamic airway collapse (EDAC)

Abstract

Excessive dynamic airway collapse (EDAC) leads to exertional and nocturnal supine dyspnoea with associated impact on quality of life (QoL). We sought to determine the effect of positive airway pressure therapy (PAP) on symptoms.

Patients with a computerised tomography (CT) or bronchoscopic diagnosis of EDAC who had received PAP (either nocturnal or ambulatory) for greater than 3 months were included. Patients were asked to report symptoms (0=none, 10=worst), sleep quality and QoL (0=worst, 10=best) on a categorical Likert scale prior to and following the initiation of PAP.

22 patients (4 male) were included: age at diagnosis 54±11yrs, BMI 36±8kg.m^-2, FEV₁ 1.6±0.5L (64±26%pred), FVC 2.5±0.7L (80±29%pred), FEV₁/FVC 65±17%, peak expiratory flow 4.5±1.7L/sec (71±27%pred), total lung capacity 5.3±1.3L (100±23%pred), TL_CO 6.4±1.5mmol/min/kPa (82±17%predicted). Eight patients were former smokers. 5/22 patients had previously received bronchoscopic intervention without any symptomatic improvement. All patients were initiated on nocturnal PAP (adherence 7±2hrs) and ambulatory continuous PAP with settings of 9±3cmH₂O. Patients reported an improvement in all symptoms. Symptom scores pre-post PAP initiation: breathlessness at rest (8.4 v 3.8, p<0.001), breathlessness on exertion (8.5 v 4.6, p<0.001), orthopnoea (7.7 v 3.8, p=0.001), cough frequency (8.3 v 3.3, p=0.001), sleep quality (2.5 v 6.8, p=0.002), QoL (2.3 v 7.5, p<0.001). Improvement was reported within days by 75%, weeks by 17% and a year by 8% of patients.

Treatment with PAP in patients with EDAC improves respiratory and sleep symptom burden significantly and enhances quality of life.