Control of Respiratory Symptoms During Sleep in Patients with Stable Bronchial Asthma

Abstract

Awareness of respiratory symptoms during day- and night-time is important for asthma control. Acoustic long-term recording offers a possibility to monitor symptoms objectively. In this prospective observational study frequency of night-time cough and wheezing was evaluated in patients with stable asthma. Night-time cough and wheezing were monitored by LEOSound lung sound monitor in 40 patients with stable asthma. Patients did not complain of respiratory problems during day- and nighttime, asthma control test was 23 points on average. FEV1 was 84 ± 15 %; MEF 50 71 ± 27 % and Rtot 0,48 ± 0,18 kPas/l. The age of the patients was 35 ± 11 years. All patients had an antiobstructive and/or anti-inflammatory medication. The present study focuses on description of frequency, severity and characteristics of night-time symptoms like cough and wheezing in patients with stable asthma and tries to depict differences in patients who present cough or wheezing. Wheezing was monitored in 2 of the 40 patients. In the first patient duration of wheezing was 19 min, in the second 55 min. Lung function in patient 1 showed a moderate bronchial obstruction, he was still smoking. Patient 2 was a non-smoker with a significant bronchial obstruction (FEV1 49 %; MEF 50 27 % and Rtot 0,52 kPas/l). In 26 patients there was no coughing, 14 patients had 4 ± 3 (2 - 13) cough epochs during the night. By dividing the collective in two groups differentiated by the presence of cough/ no cough we found no significant differences regarding lung function and ACT-scores. Both patients with night-time wheezing presented low ACT- Scores (20 and 21 points). Nocturnal wheezing and cough episodes were detectable in 2 respectively 14 patients with stable asthma. Long-term recording of normal and adventitious breath sounds offers a practical opportunity to evaluate night-time cough and wheezing objectively.