Fine crackles on chest auscultation feature prominently in idiopathic pulmonary fibrosis (IPF), making it an important finding that can be used by physicians to better screen, diagnose, and treat IPF and other forms of interstitial lung disease (ILD), according to a study published in BMJ Open Respiratory Research.
IPF is a chronic and progressive fibrosing lung disease of unknown origin with poor prognosis. In this study, researchers assessed the presence and type of crackles heard on chest auscultations in all new patients (290 in total) seen at the ILD Clinic at the Kingston Health Sciences Center (KHSC) in Ontario, Canada from 2013 to 2018. The patients referred to KHSC were suspected of having ILD based on initial chest CT scans.
At the KHSC clinic, IPF was diagnosed based on the presence of usual interstitial pneumonia (UIP) or probable UIP as identified through chest CT scans or lung biopsy results and the subsequent ruling out of known causes.
Read more about IPF diagnosis
The results found that “fine crackles were present in almost all (93%) patients with IPF and in the majority (70%) of patients with non-IPF ILD; and that almost all patients (98%) with IPF had either fine or coarse crackles on auscultation.” Fine crackles were also the most prominent feature in IPF, more than cough (86%) or dyspnea (80%). In addition, these findings were independent of variables that could affect their identification, such as the patient having comorbidities such as emphysema, COPD, or obesity.
Fine crackles on chest auscultation has always been a typical finding in IPF; however, this is the first study that assesses its diagnostic value in patients with IPF and other forms of ILD. The results of this study show that fine crackles on chest auscultation is indeed a “robust indicator” of IPF and other forms of ILD upon initial presentation, including in asymptomatic patients and patients with normal pulmonary function tests (PFTs).
The consequence of this study is that physicians can use this finding as a “sensitive, robust, and useful screening tool” in the early diagnosis and treatment of patients with IPF and other forms of ILD. Given that current antifibrotic medication can slow down the progression of fibrotic lung diseases, early diagnosis and treatment of IPF and other forms of ILD can possibly lead to better disease outcomes.
Moran-Mendoza O, Ritchie T, Aldhaheri S. Fine crackles on chest auscultation in the early diagnosis of idiopathic pulmonary fibrosis: a prospective cohort study. BMJ Open Respiratory Research. 2021;8:e000815. doi:10.1136/bmjresp-2020-000815