Proton Pump Inhibitor Treatment Improves Pulmonary Function in Acute Exacerbations of COPD Patients with 24-hour Dx-pH Monitoring-diagnosed Laryngopharyngeal Reflux.

OBJECTIVES: Chronic obstructive pulmonary disease (COPD) patients have higher laryngopharyngeal reflux (LPR)-related symptom incidence. But LPR treatment is empirical. We aimed to determine the frequency of LPR, diagnosed by 24-hour Dx-pH monitoring, among acute exacerbations of COPD (AECOPD) patients with Reflux Symptom Index (RSI) ≥ 13 and investigate proton pump inhibitor (PPI) treatment effect on LPR, COPD symptoms, and pulmonary function.

METHODS: From January 2016 to September 2017, 102 AECOPD patients with RSI ≥ 13 were enrolled. COPD assessment test (CAT), mMRC dyspnea scale, pulmonary function tests, and 24-hour Dx-pH monitoring were performed. The Ryan score was evaluated by using the Dx-pH DataView Lite software, which identifies patients with abnormal pharyngeal pH environments. Associations among RSI, pulmonary function test results, and Ryan score parameters were evaluated. The above-mentioned assessments were reperformed after treatment, and pre- and post-treatment data were compared.

RESULTS: Of the 102 eligible patients, 49 (48.04%) were diagnosed with LPR based on Ryan score. Percentage of the forced expiratory volume at 1 second (FEV1%) was significantly worse in Ryan-positive than in Ryan-negative AECOPD patients. There were significant negative correlations between FEV1% and Ryan score (r=-0.394, p＜0.001), FEV1% and % time below pH threshold (r=-0.371, p＜0.001) in upright position but not in supine position. There was no significant correlation between RSI and Ryan score parameters. There were significant improvements in RSI, mMRC, CAT and FEV1% in Ryan-positive AECOPD patients after PPI and basic treatments.

CONCLUSION: Study results indicate unreliability of RSI threshold for LPR diagnosis. Combination of symptoms, endoscopic findings, and 24-hour Dx-pH monitoring is recommended for LPR diagnosis and PPI treatment decisions, especially in difficult-to-control or severe COPD patients.