title: Computerized Respiratory Sounds: Novel Outcomes for Pulmonary Rehabilitation in COPD.
abstract: BACKGROUND
  Computerized respiratory sounds are a simple and noninvasive measure to assess lung function. Nevertheless, their potential to detect changes after pulmonary rehabilitation (PR) is unknown and needs clarification if respiratory acoustics are to be used in clinical practice. Thus, this study investigated the short- and mid-term effects of PR on computerized respiratory sounds in subjects with COPD.
  
  
  METHODS
  Forty-one subjects with COPD completed a 12-week PR program and a 3-month follow-up. Secondary outcome measures included dyspnea, self-reported sputum, FEV1, exercise tolerance, self-reported physical activity, health-related quality of life, and peripheral muscle strength. Computerized respiratory sounds, the primary outcomes, were recorded at right/left posterior chest using 2 stethoscopes. Air flow was recorded with a pneumotachograph. Normal respiratory sounds, crackles, and wheezes were analyzed with validated algorithms.
  
  
  RESULTS
  There was a significant effect over time in all secondary outcomes, with the exception of FEV1and of the impact domain of the St George Respiratory Questionnaire. Inspiratory and expiratory median frequencies of normal respiratory sounds in the 100-300 Hz band were significantly lower immediately (-2.3 Hz [95% CI -4 to -0.7] and -1.9 Hz [95% CI -3.3 to -0.5]) and at 3 months (-2.1 Hz [95% CI -3.6 to -0.7] and -2 Hz [95% CI -3.6 to -0.5]) post-PR. The mean number of expiratory crackles (-0.8, 95% CI -1.3 to -0.3) and inspiratory wheeze occupation rate (median 5.9 vs 0) were significantly lower immediately post-PR.
  
  
  CONCLUSIONS
  Computerized respiratory sounds were sensitive to short- and mid-term effects of PR in subjects with COPD. These findings are encouraging for the clinical use of respiratory acoustics. Future research is needed to strengthen these findings and explore the potential of computerized respiratory sounds to assess the effectiveness of other clinical interventions in COPD.
authors.affiliation: Research Centre in Physical Activity, Health, and Leisure (CIAFEL), Faculty of Sports, University of Porto, Porto, Portugal and Lab 3R, Respiratory Research and Rehabilitation Laboratory, School of Health Sciences, University of Aveiro (ESSUA), Aveiro, Portugal.
authors.forename: Cristina
authors.initials: C
authors.lastname: Jácome
authors.affiliation: Lab 3R, Respiratory Research and Rehabilitation Laboratory, School of Health Sciences, University of Aveiro (ESSUA), Aveiro, Portugal and the Institute for Research in Biomedicine (iBiMED), University of Aveiro, Aveiro, Portugal. amarques@ua.pt.
authors.forename: Alda
authors.initials: A
authors.lastname: Marques
mesh_terms: D000162:Acoustics; D000368:Aged; D004417:Dyspnea / Q000209:etiology; D015444:Exercise; D017079:Exercise Tolerance; D005260:Female; D005500:Follow-Up Studies; D005541:Forced Expiratory Volume; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications / Q000503:physiopathology / Q000534:rehabilitation*; D011788:Quality of Life; D012135:Respiratory Sounds; D012815:Signal Processing, Computer-Assisted; D013183:Sputum
keywords: chronic lung disease; computerized respiratory sounds; rehabilitation