Lung crackle characteristics in patients with asbestosis, asbestos-related pleural disease and left ventricular failure using a time-expanded waveform analysis--a comparative study

Our plain-English summary of Lung crackle characteristics in patients with asbestosis, asbestos-related pleural disease and left ventricular failure using a time-expanded waveform analysis--a comparative study, by N. al Jarad, S.W. Davies, R. Logan-Sinclair, et al (Respiratory Medicine, 1994).

The study

• Authors: N. al Jarad, S.W. Davies, R. Logan-Sinclair, R.M. Rudd
• Journal: Respiratory Medicine
• Published: 1994;88(1):37-46
• Cited by: 20 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

The aim of this study is to investigate lung crackle characteristics by time-expanded waveform (TEW) analysis in patients with asbestosis (AS), asbestos-related pleural disease (ARPD) and left ventricular failure (LVF). TEW was performed on a 33 s recording from each of 40 patients (12 AS, 17 ARPD and 11 LVF). They were 38 men and two women. Crackles on TEW were counted during inspiration and expiration, and the timing of clusters of crackles with respect to inspiration and expiration was noted. A total of 1117 crackles were identified. The initial deflection width (IDW) and the two cycle duration (2CD) were calculated for all crackles within one respiratory cycle for each patient (total of 298 crackles). Crackles were detected by TEW in all patients with AS, in seven patients with ARPD and in nine patients with LVF. Crackles in AS were mainly fine, mid- to late-inspiratory. Crackles in LVF took three patterns; in the first there were repetitive mid- to late inspiratory crackles similar to those seen in AS except that the crackles in LVF tended to be medium and coarse as well as fine (three patients); in the second crackles started early in inspiration followed by a crackle-free period then by another cluster of crackles lasting to the end of inspiration and to the early third of expiration (four patients) and in the third there were repetitive expiratory crackles with no or few inspiratory crackles (two patients). Crackles in ARPD generally took the configuration of fine crackles but another type of crackle preceded by a sharp deflection followed by an M-shape oscillation then by the largest oscillation was also found. IDW and 2CD for inspiratory crackles in ARPD were shorter than those in AS and LVF (for IDW P < 0.009 and P < 0.003 compared with AS and LVF respectively and for 2CD, P < 0.006 and P < 0.003 compared with AS and LVF respectively). IDW and 2CD in AS tended to be shorter than these for LVF but these results did not reach statistical significance. It is concluded that many differences exist between crackles in AS, LVF and ARPD. Differences in nature and timing of crackles may reflect differences in the pathophysiology and mechanism giving rise to lung crackles in these conditions. TEW provides informations of diagnostic value.

In plain English

This study used time-expanded waveform analysis, a recording technique, to compare lung crackles (abnormal crackling chest sounds) in 40 patients: 12 with asbestosis, 17 with asbestos-related pleural disease and 11 with left ventricular failure, a form of heart failure. Both asbestos groups had substantial asbestos exposure; none of the heart failure patients had occupational asbestos exposure. Each patient had a 33-second recording. Crackles were found in all 12 asbestosis patients, 9 of 11 heart failure patients and 7 of 17 pleural disease patients. In asbestosis, 92% of crackles were mid- to late-inspiratory (during breathing in), and inspiratory crackles were mostly fine. Heart failure crackles followed three patterns, including medium and coarse crackles. In pleural disease, crackles were fine, and the authors described an additional, distinctively shaped crackle. Two measures of inspiratory crackle width and duration were shorter in pleural disease than in the other groups. Both tended to be shorter in asbestosis than in heart failure, but not to a statistically significant degree. The authors concluded that crackles differed between the conditions and that the method can provide information of diagnostic value.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: comparative study of lung sound recordings in three patient groups
• Who was studied: 40 patients (38 men, two women): 12 with asbestosis, 11 with left ventricular failure due to coronary artery disease, and 17 with asbestos-related pleural disease; the place and dates of recruitment are not stated
• Exposure: Patients with asbestosis and patients with asbestos-related pleural disease had substantial asbestos exposure; fiber types and jobs are not given. Left ventricular failure patients had no history of occupational asbestos exposure.
• Main results:
  • Asbestosis group: crackles were detected in all 12 patients; 92% of all crackles were mid- to late-inspiratory
  • Left ventricular failure group: crackles were detected in 9 of 11 patients; 63% of crackles were inspiratory
  • Left ventricular failure group: crackles took three patterns. In four patients, early-inspiratory crackles were followed by a crackle-free period and then a further cluster. In three patients, the pattern was similar to asbestosis but with coarse and medium as well as fine crackles. In two patients, crackles were mainly expiratory with few or no inspiratory crackles.
  • Asbestos-related pleural disease group: crackles were detected in 7 of 17 patients (41%); 36% of crackles were inspiratory
  • Asbestos-related pleural disease group: another type of crackle, starting with a sharp deflection followed by an M-shape deflection and then the largest oscillation, was present in all patients with crackles
  • Inspiratory crackle width (IDW) and two-cycle duration (2CD) were shorter in asbestos-related pleural disease than in asbestosis and left ventricular failure. For IDW, P less than 0.009 compared with asbestosis and P less than 0.003 compared with left ventricular failure. For 2CD, P less than 0.006 and P less than 0.003 respectively.
  • IDW and 2CD in asbestosis tended to be shorter than in left ventricular failure, but the difference was not statistically significant
• The authors' conclusion: The authors concluded that several differences exist in the nature and distribution of crackles between asbestosis, left ventricular failure and asbestos-related pleural disease on this analysis, and that the analysis can provide information of diagnostic value
• Limitations the authors state:
  • Crackles were detected in only 7 of 17 pleural disease patients, possibly because crackles are very localized and could not be detected at the lung bases where recordings were made

Topics

The National Library of Medicine indexes this study under subjects our site covers: Asbestosis, Pleural plaques and thickening.

Medical terms in this study, explained in our Lexicon: Asbestos-Related Pleural Disease, Statistical Significance.

Related studies

• Diagnosis of asbestosis by a time expanded wave form analysis, auscultation and high resolution computed tomography: a comparative study — N. al Jarad, B. Strickland, et al. (1993)
• Crackles in the early detection of asbestosis — R.L. Murphy, E.A. Gaensler, et al. (1984)
• Crackles (rales) in the interstitial pulmonary diseases — G.R. Epler, C.B. Carrington, et al. (1978)
• Asbestos in the sputum, crackles in the lungs, and radiologic changes in women exposed to asbestos — J.C. Davies, D. Kielkowski, et al. (2004)
• The left-sided predominance of asbestos-related pleural disease — H. Hu, L. Beckett, et al. (1993)
• Rapid progression of pleural disease due to exposure to Libby amphibole: "Not your grandfather's asbestos related disease" — B. Black, J. Szeinuk, et al. (2014)

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