The role of volume reflux in patients with chronic cough detected by multichannel intraluminal impedance monitoring

The aim of the present study was to evaluate the role of acidic, non-acidic reflux events in patients with chronic cough.

Patients, methods: Twenty-two patients (M/F 3/19) mean age 46 (22–71) years, with therapy resistant chronic cough lasting more than 8 weeks with or without typical reflux symptoms were enrolled into the study. Patients had been extensively investigated by pulmonologists before referral. Upper gastrointestinal endoscopy, 24-hours simultaneous multichannel intraluminal impedance (MII) and dual-sensor pH-monitoring were performed.

Results: Endoscopy revealed erosive esophagitis in 32% of patients (5 LA-A and 2 LA-B grades) and 68% of them had non-erosive reflux disease. Abnormal 24-hour pH-score was observed in 5 of the 22 patients in the distal esophagus. Proximal acid reflux was detected in 12/22 patients. The 24-hour MII monitoring revealed proximal non-acidic reflux in 21 of 22 patients. While the number of total reflux events (87 vs. 73) and non-acidic reflux episodes (42 vs. 27) was higher than in controls, the number of acid reflux events did not exceed the normal value. Non-acidic reflux occurred predominantly in the upright position 35 vs. 7 in supine. The average number of gas-reflux episodes was 14. About one-third of all reflux episodes were proximal.

Conclusion: Non-acidic reflux seems to as important as acidic reflux in the pathogenesis of chronic cough. Negative dual-sensor pH-monitoring does not exclude pathologic reflux in GERD patients with airway manifestations.

Supported by the AstraZeneca Ltd. Hungary