Description of nighttime cough epochs in patients with stable COPD GOLD II–IV

Abstract

Purpose

Chronic cough is one of the main symptoms of COPD. Ambulatory objective monitoring provides novel insights into the determinants and characteristics of nighttime cough in COPD.

Materials and methods

Nighttime cough was monitored objectively by LEOSound lung sound monitor in patients with stable COPD II–IV. In 30 patients, with 10 patients in each stage group, nighttime cough was analyzed for epoch frequency, epoch severity (epoch length and coughs per epoch), and pattern (productive or nonproductive).

Results

Cough was found in all patients ranging from 1 to 294 events over the recording period. In 29 patients, cough epochs were monitored, ranging from 1 to 75 epochs. The highest amount of cough epochs was found in patients with COPD stage III. Active smokers had significantly more productive cough epochs (61%) than nonsmokers (24%).

Conclusion

We found a high rate of nighttime cough epochs in patients with COPD, especially in those in stage III. Productive cough was predominantly found in patients with persistent smoking. LEOSound lung sound monitor offers a practical and valuable opportunity to evaluate cough objectively.

Keywords:

• cough
• COPD
• nighttime
• cough-monitor
• lung sound
• cough epochs

Acknowledgments

This study was funded by GlaxoSmithKline plc, Brentford, UK. Preliminary results of this study have been presented at the ATS 2017 International Conference (May 19–24) in Washington, DC, USA. The abstract can be found using the following link: http://www.atsjournals.org/doi/abs/10.1164/ajrccm-conference.2017.195.1_MeetingAbstracts.A2684.

Author contributions

PF analyzed the data, designed the concept of the article, and critically evaluated the manuscript. VG and KS analyzed the data and critically evaluated the manuscript. JK carried out the measurements and critically evaluated the manuscript. AW designed the concept of the study and critically evaluated the manuscript. OH designed the concept of the study, prepared the data, and critically evaluated the manuscript. UK designed the concept of the study, the concept of the article, and critically evaluated the manuscript. All the authors approved the final manuscript as submitted.

Disclosure

Ulrich Koehler is affiliated with Löwenstein Medical GmbH & Co. KG, IfM, GlaxoSmithKline, Resmed, UCB Pharma Boehringer Ingelheim, and Sanofi. Patrick Fischer, Volker Gross, and Andreas Weissflog are affiliated with Sanofi. The other authors report no conflicts of interest in this work.