From the Guidelines
On auscultation in pneumonia, lungs typically reveal crackles (also called rales), which are discontinuous, non-musical sounds that resemble the sound of hair being rubbed between fingers, as supported by the study published in The Lancet Respiratory Medicine 1. These crackles occur due to the sudden opening of previously closed small airways and alveoli filled with fluid or exudate.
- You may also hear bronchial breath sounds over consolidated areas, which are louder and harsher than normal vesicular breath sounds, with a higher pitch and longer expiratory phase.
- Wheezes might be present if there's bronchospasm or airway narrowing.
- Decreased breath sounds can occur over areas of significant consolidation or pleural effusion.
- Egophony (enhanced vocal resonance where the spoken "E" sounds like "A" when auscultated) may be detected over consolidated lung tissue. The study by van Vugt 1 also found that the presence of breathlessness, crackles, and diminished breath sounds at auscultation, along with other symptoms and signs, can increase the likelihood of pneumonia. The absence of runny nose and the presence of these symptoms and signs, including crackles, can help diagnose pneumonia, as stated in the Chest guideline and expert panel report 1. The intensity and character of these sounds can vary depending on the stage and severity of pneumonia, with early pneumonia sometimes producing subtler findings than more advanced cases. In terms of diagnostic accuracy, the study by van Vugt 1 found that the addition of CRP levels to symptoms and signs, including crackles, can improve the diagnosis of pneumonia. However, the measurement of procalcitonin concentrations did not add relevant additional diagnostic information over symptoms and signs, including crackles, as stated in the study 1.
From the Research
Lung Sounds in Pneumonia
- Crackles, wheezes, and pleural rub are abnormal lung sounds that can be heard on auscultation in patients with pneumonia 2
- The underlying pathophysiology of lung sounds generation is important for understanding disease processes and making correct diagnoses 2
- Auscultation of the lung is a crucial part of the respiratory examination and can help diagnose various respiratory disorders, including pneumonia 2
Specific Findings in Pneumonia
- In a study on community-acquired pneumonia, respiratory sounds showed no significant differences after treatment between two groups of patients receiving different antibiotic regimens 3
- The study did not specify the types of lung sounds heard in patients with pneumonia, but it highlights the importance of auscultation in assessing respiratory symptoms 3