From the Guidelines
In a CHF exacerbation, the most common lung sounds heard are fine rales, which are usually audible over the lung fields, as noted in the European Society of Cardiology guidelines 1. These fine rales occur due to fluid accumulation in the alveoli and small airways as a result of increased pulmonary pressure from heart failure. Some key points to consider when evaluating lung sounds in CHF exacerbation include:
- Fine rales are typically heard during inspiration, particularly at the lung bases
- Wheezing may also be present, especially in cardiac asthma, where bronchospasm occurs secondary to pulmonary edema, as mentioned in the guidelines 1
- Decreased breath sounds might be detected in areas with significant fluid accumulation
- Pleural effusions associated with CHF can cause dullness to percussion and diminished breath sounds at the lung bases
- In severe cases, a pleural friction rub might be heard if there is pleural inflammation These abnormal lung sounds typically improve with diuretic therapy and other heart failure treatments that reduce pulmonary congestion, as recommended in the guidelines 1. The distribution of these sounds is often bilateral and symmetrical, starting at the bases and progressing upward as the condition worsens, reflecting the gravitational distribution of pulmonary edema. It's worth noting that the European Society of Cardiology guidelines from 2012 1 also highlight the importance of symptoms and signs in monitoring a patient’s response to treatment and stability over time. However, the most recent and highest quality study that specifically addresses lung sounds in CHF exacerbation is the 2005 European Society of Cardiology guidelines 1, which provides the most relevant information for this question.
From the Research
Lung Sounds in CHF Exacerbation
- Crackles (rales) are a common lung sound heard in patients with congestive heart failure (CHF) exacerbation, particularly in those with pulmonary edema 2
- The presence of crackles can indicate fluid accumulation in the lungs, which is a hallmark of CHF exacerbation
- Age-related pulmonary crackles (rales) can also be present in asymptomatic cardiovascular patients, and their prevalence increases with age 3
- In patients with CHF, the presence of crackles can be associated with dyspnea and other symptoms, and their resolution can be an indicator of treatment efficacy 2
- Other lung sounds, such as wheezes or rhonchi, may also be present in patients with CHF exacerbation, but crackles are the most commonly associated lung sound
- The characteristics of pulmonary crackles in CHF patients can vary, and their presence and severity can be influenced by factors such as age, disease severity, and treatment response 3