Getting the most from pleural fluid analysis
Article first published online: 24 JAN 2012
© 2011 The Authors. Respirology © 2011 Asian Pacific Society of Respirology
Volume 17, Issue 2, pages 270–277, February 2012
How to Cite
SAHN, S. A. (2012), Getting the most from pleural fluid analysis. Respirology, 17: 270–277. doi: 10.1111/j.1440-1843.2011.02100.x
- Issue published online: 24 JAN 2012
- Article first published online: 24 JAN 2012
- Accepted manuscript online: 7 NOV 2011 11:07PM EST
- Received 11 August 2011; invited to revise 28 August 2011, 10 September 2011; revised 30 August 2011, 12 September 2011; accepted 23 September 2011 (Associate Editor: José Porcel).
- pleural fluid;
- pleural fluid analysis;
Virtually, every pulmonary disease and most non-pulmonary diseases may be associated with a pleural effusion. The presence of a pleural effusion allows the clinician to ‘diagnose’ or narrow the differential diagnosis and aetiology of the fluid collection. However, pleural fluid analysis (PFA) in isolation rarely provides a definitive diagnosis. This review discusses the rationale for evaluating patients with a pleural effusion. If the clinician obtains a detailed history, performs a comprehensive physical examination, reviews pertinent blood tests, and evaluates the chest imaging findings prior to thoracentesis, there should be a high likelihood of establishing a firm clinical diagnosis based on the appropriate PFA. This manuscript reviews the clinical presentation, chest imaging findings, duration and natural course of specific pleural effusions to help narrow the range of pre-thoracentesis diagnoses. A diagnosis of transudative effusion confirms an imbalance in hydrostatic and oncotic pressures, normal pleura and a limited differential diagnosis, which is typically apparent from the clinical presentation. Exudates are the result of infections, malignancies, inflammation, impaired lymphatic drainage or the effects of drugs, and pose a greater diagnostic challenge. The differential diagnosis for a pleural exudate can be narrowed if LDH levels exceed 1000 IU/L, the proportion of lymphocytes is ≥80%, pleural fluid pH is <7.30 or there is pleural eosinophilia of >10%.