Author: Ioannis Psallidas
Pleural effusion is a feature of a wide range of diseases. Transudative and exudative effusions (Tables 12.1 and 12.2) are caused by distinctive pathogenic mechanisms, and Light's criteria should be used for their differentiation.
Evaluation requires clinical assessment, imaging (by chest X-ray and thoracic ultrasonography) and examination of pleural fluid. Assessment and management of pleural effusion is summarized in Figure 12.1.
Clinical Assessment and Imaging
The clinical assessment is summarized in Table 12.3.
Categorizing an Effusion As a Transudate or an Exudate
To answer this important question, Light's criteria should be employed. The effusion is an exudate if it meets one of the following criteria:
Light's criteria correctly identify almost all exudates, but mis-classifies about 20% of transudates as exudates. If a transudative effusion is suspected (e.g. due to heart failure or cirrhosis) and none of the biochemical measurements is >15% above the cutoff levels for Light's criteria, the difference between serum and the pleural fluid protein is measured. If the difference is >31g/L, the effusion is probably a transudate.
Treatment of Symptoms and Underlying Disorder
Drainage of a Symptomatic Effusion
Specific Management for Parapneumonic Effusions and Empyema
Specific Management for Malignant Pleural Effusions
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Psallidas I, Kalomenidis I, Porcel JM, Robinson BW, Stathopoulos GT (2016) Malignant pleural effusion: from bench to bedside. European Respiratory Review 25, 189198. DOI: 10.1183/16000617.0019-2016.