From the Guidelines
Loculated pleural effusions are primarily caused by the formation of fibrin strands and adhesions within the pleural space, resulting from conditions such as complicated parapneumonic effusions, empyema, tuberculosis, hemothorax, malignant pleural effusions, post-surgical or post-traumatic effusions, rheumatoid arthritis, and asbestos exposure. The most common causes of loculated pleural effusions can be broken down into several categories:
- Infections: Complicated parapneumonic effusions and empyema, where bacterial infections lead to inflammation and fibrin deposition 1
- Autoimmune conditions: Rheumatoid arthritis and other autoimmune conditions can cause loculated effusions through chronic inflammation
- Trauma: Hemothorax can lead to loculations when blood in the pleural space organizes and forms adhesions
- Malignancies: Malignant pleural effusions, particularly from lung cancer, breast cancer, and lymphoma, can become loculated as tumor cells trigger inflammatory responses 1
- Environmental exposures: Asbestos exposure leading to mesothelioma or benign asbestos pleural effusion commonly results in loculations The pathophysiology involves inflammation that increases pleural membrane permeability, allowing fibrin and inflammatory cells to enter the pleural space, forming adhesions that trap fluid in separate pockets 1. These loculations often require more aggressive drainage approaches such as intrapleural fibrinolytics, thoracoscopy, or surgical intervention rather than simple thoracentesis. According to the most recent and highest quality study, the use of intrapleural fibrinolytics, such as streptokinase or urokinase, can improve fluid drainage and reduce symptoms in patients with loculated pleural effusions 1.
From the Research
Causes of Loculated Pleural Effusion
The causes of loculated pleural effusion can be varied and are often related to the underlying conditions that lead to pleural effusion. Some of the common causes include:
- Congestive heart failure
- Cancer, such as lung cancer or breast cancer 2
- Pneumonia 3, 4, 2
- Pulmonary embolism 2
- Malignancy 3
Etiology and Diagnosis
Determining the etiology of pleural effusion is crucial for proper treatment and management. The diagnostic evaluation of pleural effusion includes chemical and microbiological studies, as well as cytological analysis 4. Thoracocentesis should be performed for new and unexplained pleural effusions to distinguish between transudate and exudate 4.
Treatment and Management
The treatment of loculated pleural effusion depends on the underlying cause. For example, transudative effusions are usually managed by treating the underlying medical disorder, while exudative effusions require specific treatment based on their etiology 4. In some cases, pleurodesis, thoracoscopy, or video-assisted thoracoscopy may be necessary 2. The use of a small caliber catheter and urokinase (pleuro-fibrinolysis) has been shown to be effective in draining loculated and/or multiloculated pleural effusions 5.