Increase of weakly acidic gas esophagopharyngeal reflux (EPR) and swallowing-induced acidic/weakly acidic EPR in patients with chronic cough responding to proton pump inhibitors
Version of Record online: 6 JAN 2011
© 2011 Blackwell Publishing Ltd
Neurogastroenterology & Motility
Volume 23, Issue 5, pages 411–e172, May 2011
How to Cite
Kawamura, O., Shimoyama, Y., Hosaka, H., Kuribayashi, S., Maeda, M., Nagoshi, A., Zai, H. and Kusano, M. (2011), Increase of weakly acidic gas esophagopharyngeal reflux (EPR) and swallowing-induced acidic/weakly acidic EPR in patients with chronic cough responding to proton pump inhibitors. Neurogastroenterology & Motility, 23: 411–e172. doi: 10.1111/j.1365-2982.2010.01658.x
- Issue online: 11 APR 2011
- Version of Record online: 6 JAN 2011
- Received: 8 June 2010 Accepted for publication: 7 December 2010
- 24-h pharyngo-esophageal impedance and pH monitoring;
- chronic cough;
- gastro-esophageal reflux disease;
- swallowing-induced pharyngeal reflux;
- weakly acidic pharyngeal gas reflux
Background Gastro-esophageal reflux disease (GERD)-related chronic cough (CC) may have multifactorial causes. To clarify the characteristics of esophagopharyngeal reflux (EPR) events in CC patients whose cough was apparently influenced by gastro-esophageal reflux (GER), we studied patients with CC clearly responding to full-dose proton pump inhibitor (PPI) therapy (CC patients).
Methods Ten CC patients, 10 GERD patients, and 10 healthy controls underwent 24-h ambulatory pharyngo-esophageal impedance and pH monitoring. Weakly acidic reflux was defined as a decrease of pH by >1 unit with a nadir pH >4. In six CC patients, monitoring was repeated after 8 weeks of PPI therapy. The number of each EPR event and the symptom association probability (SAP) were calculated. Symptoms were evaluated by a validated GERD symptom questionnaire.
Key Results Weakly acidic gas EPR and swallowing-induced acidic/weakly acidic EPR only occurred in CC patients, and the numbers of such events was significantly higher in the CC group than in the other two groups (P < 0.05, respectively). Symptom association probability analysis revealed a positive association between GER and cough in three CC patients. Proton pump inhibitor therapy abolished swallowing-induced acidic/weakly acidic EPR, reduced weakly acidic gas EPR, and improved symptoms (all P < 0.05).
Conclusions & Inferences Most patients with CC responding to PPI therapy had weakly acidic gas EPR and swallowing-induced acidic/weakly acidic EPR. A direct effect of acidic mist or liquid refluxing into the pharynx may contribute to chronic cough, while cough may also arise indirectly from reflux via a vago-vagal reflex in some patients.