What are the sounds associated with pleural effusion?

From the Guidelines

Pleural effusion sounds like decreased or absent breath sounds over the affected area during auscultation with a stethoscope. When examining a patient with pleural effusion, you'll typically hear diminished breath sounds at the base of the lung where fluid has accumulated. Percussion of this area produces a dull sound rather than the normal resonance of healthy lung tissue. If you ask the patient to say "E" while listening with your stethoscope, you may notice decreased vocal fremitus (reduced transmission of voice sounds) over the effusion. Sometimes, you might hear a pleural friction rub, which sounds like leather rubbing together, especially if there's inflammation of the pleural surfaces. In large effusions, breath sounds may be completely absent over the affected area. These characteristic findings occur because the fluid in the pleural space dampens sound transmission and separates the visceral and parietal pleura, creating a buffer zone that alters normal respiratory acoustics.

Key Findings

• Diminished breath sounds at the base of the lung
• Dull sound on percussion
• Decreased vocal fremitus
• Possible pleural friction rub
• Absent breath sounds in large effusions

According to the British Thoracic Society guideline for pleural disease 1, a careful history and physical examination of the patient remains the most important first step when evaluating someone with an undiagnosed pleural effusion. Thoracic ultrasound (TUS) is also a crucial diagnostic tool, and it should be performed on every patient at their initial presentation and again whenever a pleural procedure is being performed. The American College of Chest Physicians evidence-based clinical practice guidelines 1 also emphasize the importance of TUS in diagnosing pleural effusions, particularly in differentiating between malignant and benign effusions.

Diagnostic Approach

• Careful history and physical examination
• Thoracic ultrasound (TUS)
• Pleural aspiration or biopsy if necessary
• CT scan if malignancy is suspected or if pleural aspiration is not possible

It's essential to note that the diagnostic approach may vary depending on the patient's presentation and the suspected underlying cause of the pleural effusion. However, a thorough physical examination and the use of TUS are essential components of the diagnostic workup. By following this approach, clinicians can quickly and accurately diagnose pleural effusions and develop an effective treatment plan to improve patient outcomes.

From the Research

Pleural Effusion Sounds

• Pleural effusion is characterized by an excessive accumulation of fluid in the pleural space, which can cause various symptoms, including dyspnea, dry cough, and pleuritic chest pain 2.
• The sounds associated with pleural effusion are not explicitly described in the provided studies, but it can be inferred that the condition may cause abnormal lung sounds due to the accumulation of fluid in the pleural space.
• Patients with pleural effusion may exhibit decreased or absent breath sounds over the affected area, as well as dullness to percussion 3.
• The diagnostic evaluation of pleural effusion includes physical examination, chest radiography, and thoracentesis, which can help identify the underlying cause of the condition and guide treatment 2, 4, 3.

Diagnostic Approach

• Thoracentesis is a crucial diagnostic procedure for pleural effusion, allowing for the collection of pleural fluid for laboratory analysis and helping to differentiate between transudative and exudative effusions 2, 4, 3.
• Ultrasound guidance is preferred when performing thoracentesis to ensure accurate and safe aspiration of fluid 3.
• Laboratory assays, such as protein and lactate dehydrogenase levels, Gram staining, cytology, and pH measurement, are essential for diagnosing the underlying cause of pleural effusion 3.

Treatment and Management

• The treatment of pleural effusion depends on the underlying cause, with transudative effusions typically managed by treating the underlying medical disorder, and exudative effusions requiring more specific treatment, such as pleurodesis or thoracoscopy 2, 4.
• Thoracentesis can provide symptomatic relief for patients with large, refractory pleural effusions, and may be performed in conjunction with other treatments, such as diuretics or antibiotics 2, 5, 6.