Diagnostic Approach to Pleural Effusion



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Am Fam Physician. 2014 Jul 15;90(2):99-104.

This clinical content conforms to AAFP criteria for continuing medical education (CME). See CME Quiz Questions.

  Patient information: See related handout on pleural effusion, written by the authors of this article.

Pleural effusion affects more than 1.5 million people in the United States each year and often complicates the management of heart failure, pneumonia, and malignancy. Pleural effusion occurs when fluid collects between the parietal and visceral pleura. Processes causing a distortion in body fluid mechanics, such as in heart failure or nephrotic syndrome, tend to cause transudative effusions, whereas localized inflammatory or malignant processes are often associated with exudative effusions. Patients can be asymptomatic or can present with cough, dyspnea, and pleuritic chest pain. Dullness to percussion on physical examination suggests an effusion; chest radiography can confirm the diagnosis. Thoracentesis may be indicated to diagnose effusion and relieve symptoms. Ultrasound guidance is preferred when aspirating fluid. Routine assays for aspirated fluid include protein and lactate dehydrogenase levels, Gram staining, cytology, and pH measurement. Light's criteria should be used to differentiate exudative from transudative effusions. Additional laboratory assays, bronchoscopy, percutaneous pleural biopsy, or thoracoscopy may be required for diagnosis if the initial test results are inconclusive.

More than 1.5 million persons develop pleural effusions each year in the United States.1 Many of the disease processes commonly seen in primary care are associated with pleural effusion, which requires family physicians to be familiar with its causes, diagnosis, and management.

SORT: KEY RECOMMENDATIONS FOR PRACTICE

Clinical recommendation Evidence rating References Comments

Thoracentesis should be performed with ultrasound guidance.

A

10, 20, 24

Ultrasonography increases the likelihood of successful aspiration, decreases the risk of organ puncture (odds ratio for pneumothorax with ultrasonography = 0.3 to 0.8), and is associated with lower hospital costs.

Light's criteria should be used to differentiate transudative from exudative effusions.

C

10, 27, 28

Light's criteria have a diagnostic accuracy of 93% to 96%.

In patients with a pleural effusion classified as exudative by Light's criteria in which a cardiac etiology is suspected, N-terminal pro-brain natriuretic peptide can help differentiate cardiac from noncardiac conditions.

C

10, 11


A = consistent, good-quality patient-oriented evidence; B = inconsistent or limited-quality patient-oriented evidence; C = consensus, disease-oriented evidence, usual practice, expert opinion, or case series. For information about the SORT evidence rating system, go to http://www.aafp.org/afpsort.

SORT: KEY RECOMMENDATIONS FOR PRACTICE

View Table

SORT: KEY RECOMMENDATIONS FOR PRACTICE

Clinical recommendation Evidence rating References Comments

Thoracentesis should be performed with ultrasound guidance.

A

10, 20, 24

Ultrasonography increases the likelihood of successful aspiration, decreases the risk of organ puncture (odds ratio for pneumothorax with ultrasonography = 0.3 to 0.8), and is associated with lower hospital costs.

Light's criteria should be used to differentiate transudative from exudative effusions.

C

10, 27, 28

Light's criteria have a diagnostic accuracy of 93% to 96%.

In patients with a pleural effusion classified as exudative by Light's criteria in which a cardiac etiology is suspected, N-terminal pro-brain natriuretic peptide can help differentiate cardiac from noncardiac conditions.

C

10, 11


A = consistent, good-quality patient-oriented evidence; B = inconsistent or limited-quality patient-oriented evidence; C = consensus, disease-oriented evidence, usual practice, expert opinion, or case series. For information about the SORT evidence rating system, go to http://www.aafp.org/afpsort.

Etiology and Pathogenesis

The visceral and parietal pleural membranes border a potential space within the thoracic cavity. Normally, a small physiologic amount of pleural fluid (0.1 mL per kg) rests within this space. Oncotic and hydrostatic pressures regulate fluid movement between the pleura, which adapt to a range of pressures to maintain the amount of fluid within a preset range. Abnormally high capillary and interstitial hydrostatic pressures can cause an abnormal accumulation of pleural fluid (e.g., in heart failure), as can an abnormally decreased capillary oncotic pressure (e.g., in nephrotic syndrome). Fluid that accumulates as a result of an imbalance in these forces produces transudative effusions. Additionally, inflammatory and malignant processes can promote local capillary and pleural membrane permeability or lymphatic blockage, which allows for the accumulation of exudative pleural fluid (i.e., fluid that is higher in protein and lactate dehydrogenase than transudative fluid).2 Furthermore, an inter

The Author

AARON SAGUIL, MD, MPH, is assistant dean for recruitment and admissions and an assistant professor of family medicine at the Uniformed Services University of the Health Sciences in Bethesda, Md.

KRISTEN WYRICK, MD, is a family physician at Joint Base Langley-Eustis, Va., and an Air Force Reserve physician and assistant professor of family medicine at the Uniformed Services University of the Health Sciences.

JOHN HALLGREN, MD, is an assistant professor of family medicine at the Uniformed Services University of the Health Sciences and the University of Nebraska Medical Center in Omaha.

Author disclosure: No relevant financial affiliations.

Address correspondence to Aaron Saguil, MD, MPH, Uniformed Services University of the Health Sciences, Office of Recruitment and Admissions, 4301 Jones Bridge Rd., Bethesda, MD 20814 (e-mail: aaron.saguil@usuhs.edu). Reprints are not available from the authors.


The opinions and assertions contained herein are the private views of the authors and are not to be construed as official or as reflecting the views of the U.S. Army, Navy, or Air Force Medical Departments or the U.S. Army, Navy, Air Force, or Public Health Service.

REFERENCES

1. Light RW. Pleural effusions. Med Clin North Am. 2011;95(6):1055–1070.

2. Zarogiannis S, et al. Physiology of the pleura. In: Bouros D, ed. Pleural Disease. 2nd ed. London, U.K.: Informa Healthcare; 2009:1–8.

3. Roussos A, et al. Hepatic hydrothorax: pathophysiology diagnosis and management. J Gastroenterol Hepatol. 2007;22(9):1388–1393.

4. Kataoka H. Pericardial and pleural effusions in decompensated chronic heart failure. Am Heart J. 2000;139(5):918–923.

5. Light RW, et al. Parapneumonic effusions. Am J Med. 1980;69(4):507–512.

6. Porcel JM, et al. Pleural effusions due to pulmonary embolism. Curr Opin Pulm Med. 2008;14(4):337–342.

7. American Thoracic Society. Management of malignant pleural effusions. Am J Respir Crit Care Med. 2000;162(5):1987–2001.

8. Labidi M, et al. Pleural effusions following cardiac surgery: prevalence, risk factors, and clinical features. Chest. 2009;136(6):1604–1611.

9. Boylan AM, et al. Pleural disease. In: Schraufnagel DE, Kell B, eds. Breathing in America: Diseases, Progress, and Hope. New York, NY: American Thoracic Society; 2010:145–154.

10. Hooper C, et al. Investigation of a unilateral pleural effusion in adults: British Thoracic Society pleural disease guideline 2010. Thorax. 2010;65(suppl 2):ii4–ii17.

11. McGrath EE, et al. Diagnosis of pleural effusion: a systematic approach. Am J Crit Care. 2011;20(2):119–127.

12. Fine NL, et al. Frequency of pleural effusions in mycoplasma and viral pneumonias. N Engl J Med. 1970;283(15):790–793.

13. Light RW. Clinical practice. Pleural effusion. N Engl J Med. 2002;346 (25):1971–1977.

14. Hillerdal G. Chylothorax and pseudochylothorax. Eur Respir J. 1997;10(5):1157–1162.

15. Pneumotox Online. Pleural effusion. http://www.pneumotox.com/pattern/view/31/V.a/pleural-effusion/. Accessed April 11, 2012.

16. Ferrer JS, et al. Evolution of idiopathic pleural effusion: a prospective, long-term follow-up study. Chest. 1996;109(6):1508–1513.

17. Wong CL, et al. Does this patient have a pleural effusion? JAMA. 2009;301(3):309–317.

18. Porcel JM, et al. Diagnostic approach to pleural effusion in adults. Am Fam Physician. 2006;73(7):1211–1220.

19. Mandell LA, et al. Infectious Diseases Society of America/American Thoracic Society consensus guidelines on the management of community-acquired pneumonia in adults. Clin Infect Dis. 2007;44(suppl 2):S27–S72.

20. Gordon CE, et al. Pneumothorax following thoracentesis: a systematic review and meta-analysis. Arch Intern Med. 2010;170(4):332–339.

21. Lichtenstein D, et al. Comparative diagnostic performances of auscultation, chest radiography, and lung ultrasonography in acute respiratory distress syndrome. Anesthesiology. 2004;100(1):9–15.

22. Light RW. Pleural Diseases. 4th ed. Philadelphia, Pa.: Lippincott Williams & Wilkins; 2001.

23. Havelock T, et al. Pleural procedures and thoracic ultrasound: British Thoracic Society pleural disease guideline 2010. Thorax. 2010;65(suppl 2):ii61–ii76.

24. Patel PA, et al. Ultrasonography guidance reduces complications and costs associated with thoracentesis procedures. J Clin Ultrasound. 2012;40(3):135–141.

25. Wilcox ME, et al. Does this patient have an exudative pleural effusion? The rational clinical examination systematic review. JAMA. 2014;311(23):2422–2431.

26. Alemán C, et al. The value of chest roentgenography in the diagnosis of pneumothorax after thoracentesis. Am J Med. 1999;107(4):340–343.

27. Romero-Candeira S, et al. Is it meaningful to use biochemical parameters to discriminate between transudative and exudative pleural effusions? Chest. 2002;122(5):1524–1529.

28. Light RW, et al. Pleural effusions: the diagnostic separation of transudates and exudates. Ann Intern Med. 1972;77(4):507–513.

29. Murphy MJ, et al. Categorisation of pleural fluids in routine clinical practice: analysis of pleural fluid protein and lactate dehydrogenase alone compared with modified Light's criteria. J Clin Pathol. 2008;61(5):684–685.

30. Porcel JM. Pearls and myths in pleural fluid analysis. Respirology. 2011;16(1):44–52.

31. Janda S, et al. Diagnostic accuracy of pleural fluid NT-pro-BNP for pleural effusions of cardiac origin: a systematic review and meta-analysis. BMC Pulm Med. 2010;10:58.



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