Chest
Volume 128, Issue 3, September 2005, Pages 1468-1474
Journal home page for Chest

Clinical Investigations
Transmission of Crackles in Patients With Interstitial Pulmonary Fibrosis, Congestive Heart Failure, and Pneumonia

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Objective

Patients with interstitial pulmonary fibrosis (IPF) often have diffusely abnormal findings on chest radiographs, making it difficult to detect evidence of superimposed congestive heart failure (CHF) or pneumonia. The goal of this study was to determine whether the crackles of IPF differed in their transmission and frequency from crackles of CHF and pneumonia in the hope of improving diagnosis and monitoring of these patients.

Methods

A multichannel lung sound analyzer was used to collect 20-s samples of sound from 25 patients with pneumonia, 17 patients with CHF, and 19 patients with IPF. We calculated a crackle transmission coefficient (CTC) by quantifying the distance a crackle spreads using a technique that cross-correlated the signal containing the highest amplitude crackle with the corresponding signal on all other ipsilateral channels: CTC, 0% = no transmission; CTC, 100% = equal transmission to all channels.

Results

Both the CTC and the crackle frequency in IPF were statistically different from that in CHF and pneumonia (p < 0.0001). The CTC averaged 24 ± 5% for pneumonia, 25 ± 8% for CHF, and 14 ± 4% for IPF. The crackle frequency averaged 302 ± 47 Hz for pneumonia, 311 ± 62 Hz for CHF, and 462 ± 50 Hz for IPF (± SD).

Conclusion

These differences in CTC and crackle frequency offer the promise of helping guide treatment in IPF patients.

Section snippets

Patient Selection

Patients were selected for this study from a pool of patients who had undergone lung sound analysis as a part of a broader study of the correlation of disease processes with lung sounds patterns. To acquire patients into this study, we identified hospitalized patients and outpatients of a community teaching hospital who had a specific cardiopulmonary disease diagnosis or were considered to be normal by their caregivers. The studies are not made on consecutive patients; this is a convenience

Development and Validation of the Concept of Crackle Family

The concept of “crackle families” resulted from observing the patterns of crackles as they appear on time-expanded waveform analysis. Figure 2 shows time-expanded sound waveforms recorded from a patient with pneumonia. The waveforms are superimposed on a body plot. Each waveform is positioned on the part of the body where the sound was recorded. A prominent crackle is seen on the tracing from channel 15 (indicated by a large triangle). Crackle waveforms that occur at approximately the same time

Discussion

In this study, we have described criteria that differentiate IPF patients from CHF and pneumonia patients on the basis of crackle transmission and frequency. Crackles in IPF patients had a strong tendency to be of higher frequency than the crackles of CHF and pneumonia as has been reported.6 The higher-frequency crackles of IPF patients in this study were transmitted through the chest to a much smaller degree than crackles in CHF and pneumonia patients. The smaller degree of crackle

References (8)

  • DonnerbergRL et al.

    Sound transfer function of the congested canine lung

    Br J Dis Chest

    (1980)
  • BergstresserT et al.

    Sound transmission in the lung as a function of lung volume

    J Appl Physiol

    (2002)
  • MurphyRL et al.

    Automated lung sound analysis in patients with pneumonia

    Respir Care

    (2004)
  • MurphyRLH et al.

    Visual lung sound characterization by time expanded wave-form analysis

    N Engl J Med

    (1977)
There are more references available in the full text version of this article.

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    Therefore, multi-channel lung sound analysis provides useful information. Because a misinterpretation of crackles could lead to inappropriate therapy [44], further experiments, including the mentioned diseases, are needed to evaluate if an accurate distinction is possible. Furthermore, the inclusion of metadata should be considered for the classification.

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    With these modifications, our results show that MRC of Velcro rales is significantly higher than that of other crackles, which indicates that Velcro rales mostly appear in late inspiration. This observation is consistent with previous results [32,34]. Although our results showed evidence that the proposed analytical method and the designed device may serve as a promising tool to detect ILD-related crackles, there are certain limitations regarding the underlying mechanisms and the potential clinical application.

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    They are discontinuous type of adventitious sounds superimposed on vesicular sounds, and may be heard all over the chest wall. Their regional distribution over the chest, their number per respiratory cycle, their timing within a respiratory cycle and their waveforms are usually indicators of the type and severity of the underlying pulmonary pathology [1–9]. Since the invention of the first stethoscope by the French physician René Laennec in 1816, physicians have given special attention to crackles in correlating acoustic information with disorders, and thus have tried to describe and classify crackle types according to the auditory perception of crackling sounds with qualitative terms such as “dry”, “humid”, “sonorous” and “sibilous” [10].

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Dr. Murphy and Dr. Vyshedskiy have financial interests in Stethographics, Inc.

Supported by a National Institutes of Health small business innovation research grant (1R43HL70480–01) and a grant from Stethographics, Inc.

Reproduction of this article is prohibited without written permission from the American College of Chest Physicians (www.chestjournal.org/misc/reprints.shtml).

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