From the Research
Inspiratory and Expiratory Crackles
- Inspiratory and expiratory crackles are sounds that can be heard on auscultation of the chest and are often associated with various pulmonary disorders 1, 2.
- The mechanism of production of these sounds is thought to be related to the sudden opening or closing of airways during inspiration or expiration, respectively 1, 2.
- Studies have shown that inspiratory crackles are almost twice as numerous as expiratory crackles and have predominately negative polarity 1.
Clinical Significance
- Crackles can be an important diagnostic tool in the identification of various pulmonary disorders, including chronic obstructive pulmonary disease (COPD) 3, idiopathic pulmonary fibrosis (IPF) 4, and pneumonia 1.
- The timing, pitch, and waveform of crackles can provide valuable information about the underlying pulmonary pathophysiology 2.
- Fine crackles on chest auscultation have been shown to be a sensitive and robust screening tool for the early diagnosis of IPF 4.
Chest Tube Insertion
- There is limited evidence to suggest that inspiratory and expiratory crackles are normal after chest tube insertion 5.
- However, it is possible that crackles may be heard after chest tube insertion due to the underlying condition that required the insertion of the chest tube, such as pneumothorax or pleural effusion.
- Further research is needed to determine the clinical significance of crackles after chest tube insertion.