PURPOSE: The crackles heard in patients with IPF have been described as distinctive from those in the other conditions commonly associated with crackles. Although there is some objective information to support this claim it has been obtained on only a small number of patients and at few sites on the chest. We used a multichannel lung sound analyzer to study patients with IPF to determine whether this claim was true and if so what was the degree of objectively measured differences in the crackles of IPF as compared to the crackles found in other common cardiopulmonary conditions.
METHODS: From a database of nearly 1000 patients studied at a community teaching hospital, we selected patients with the following diagnoses: Interstitial Pulmonary Fibrosis (IPF), Pneumonia (PN), Congestive Heart Failure (CHF), Asthma, COPD and patients with no history of cardiopulmonary disease. They were examined using a multichannel lung sound analyzer, which analyzes sounds from 14 sites over the chest (Stethographics, STG1602).
RESULTS: As can be seen in the table, inspiratory crackles were more numerous in IPF and had higher frequency than those in the other conditions. These crackles tended to be paninspiratory in timing.
CONCLUSION: The reported findings are consistent with the hypothesis that the crackles of IPF are significantly different from the crackles heard in common cardiopulmonary conditions that are associated with crackles.
CLINICAL IMPLICATIONS: Patients with IPF are commonly treated with diuretics because their crackles are mistaken for those of CHF. Improved education in the identification of the crackles of IPF or objective measurement of them could help alleviate this problem. Similarly recognition of these crackles in patients could facilitate earlier diagnosis of IPF.
DISCLOSURE: Raymond Murphy, Shareholder Dr. Murphy is founder and CMO of Stethographics, Inc.