Is the pleural fluid transudate or exudate? A revisit of thediagnostic criteria
J Joseph
P Badrinath
G Basran
S Sahn
Abstract
BACKGROUND—Pleuraleffusions are classified into transudates and exudates based oncriteria developed in the 1970s. However, their accuracy has not beenevaluated. We compared the performance of the pleural fluid absolutelactic dehydrogenase level (FLDH), fluid to serum ratio of LDH (LDHR),and fluid to serum ratio of total protein (TPR). TPR has been usedinstead of the absolute value of fluid protein based on the observationthat fluid protein is influenced by changes in the serum proteinconcentration. However, the rationale for using LDHR remains unexplored. METHODS—Of 212 consecutive patients with pleural effusions, four with multiple causesand eight with an uncertain diagnosis were excluded. ROC curves weregenerated using sensitivity and 1-specificity values for TPR, FLDH,and LDHR and positive likelihood ratios (LR +ve) were computed usingthe optimum cut off values. The correlation between pleural fluid andserum concentrations of total protein and LDH was also estimated. RESULTS—Of 200 effusions studied, 156 were exudates and 44 were transudates. Theoptimum cut off levels were: FLDH 163 IU/l, TPR 0.5,LDHR 0.6, and theFLDH-TPR combination 163 and 0.4, respectively. The area under thecurve (AUC) with 95% confidence interval (CI) was: 0.89 (0.86 to 0.96)for FLDH, 0.86 (0.80 to 0.91) for TPR, 0.82 (0.77 to 0.89) for LDHR,and 0.90 (0.86 to 95) for FLDH-TPR. A significant correlation wasobserved between serum and pleural fluid protein levels in transudatesand exudates (r=0.5 and 0.6,respectively),but the correlation between serum and pleural fluid LDH levels was insignificant. CONCLUSION—FLDH is themost accurate marker for the diagnostic separation of transudates andexudates and LDHR has no role in this process. Combining TPR with FLDHappears to improve the diagnostic accuracy slightly.
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- Allen S., Gabel J., Drake R. Left atrial hypertension causes pleural effusion formation in unanesthetized sheep. Am J Physiol. 1989 Aug;257(2 Pt 2):H690–H692. doi: 10.1152/ajpheart.1989.257.2.H690. [DOI] [PubMed] [Google Scholar]
- Black L. F. The pleural space and pleural fluid. Mayo Clin Proc. 1972 Jul;47(7):493–506. [PubMed] [Google Scholar]
- Broaddus V. C., Wiener-Kronish J. P., Staub N. C. Clearance of lung edema into the pleural space of volume-loaded anesthetized sheep. J Appl Physiol (1985) 1990 Jun;68(6):2623–2630. doi: 10.1152/jappl.1990.68.6.2623. [DOI] [PubMed] [Google Scholar]
- Chakko S. C., Caldwell S. H., Sforza P. P. Treatment of congestive heart failure. Its effect on pleural fluid chemistry. Chest. 1989 Apr;95(4):798–802. doi: 10.1378/chest.95.4.798. [DOI] [PubMed] [Google Scholar]
- Chandrasekhar A. J., Palatao A., Dubin A., Levine H. Pleural fluid lactic acid dehydrogenase activity and protein content. Value in diagnosis. Arch Intern Med. 1969 Jan;123(1):48–50. [PubMed] [Google Scholar]
- Hanley J. A., McNeil B. J. A method of comparing the areas under receiver operating characteristic curves derived from the same cases. Radiology. 1983 Sep;148(3):839–843. doi: 10.1148/radiology.148.3.6878708. [DOI] [PubMed] [Google Scholar]
- Heffner J. E., Brown L. K., Barbieri C. A. Diagnostic value of tests that discriminate between exudative and transudative pleural effusions. Primary Study Investigators. Chest. 1997 Apr;111(4):970–980. doi: 10.1378/chest.111.4.970. [DOI] [PubMed] [Google Scholar]
- Hoefs J. C. Serum protein concentration and portal pressure determine the ascitic fluid protein concentration in patients with chronic liver disease. J Lab Clin Med. 1983 Aug;102(2):260–273. [PubMed] [Google Scholar]
- Jay S. J. Diagnostic procedures for pleural disease. Clin Chest Med. 1985 Mar;6(1):33–48. [PubMed] [Google Scholar]
- Light R. W., Macgregor M. I., Luchsinger P. C., Ball W. C., Jr Pleural effusions: the diagnostic separation of transudates and exudates. Ann Intern Med. 1972 Oct;77(4):507–513. doi: 10.7326/0003-4819-77-4-507. [DOI] [PubMed] [Google Scholar]
- Melsom R. D. Diagnostic reliability of pleural fluid protein estimation. J R Soc Med. 1979 Nov;72(11):823–825. doi: 10.1177/014107687907201106. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Paavonen T., Liippo K., Aronen H., Kiistala U. Lactate dehydrogenase, creatine kinase, and their isoenzymes in pleural effusions. Clin Chem. 1991 Nov;37(11):1909–1912. [PubMed] [Google Scholar]
- Sahn S. A. State of the art. The pleura. Am Rev Respir Dis. 1988 Jul;138(1):184–234. doi: 10.1164/ajrccm/138.1.184. [DOI] [PubMed] [Google Scholar]
- Smith M. J., Joseph J., Flatman W. D., Basran G. S. A dual-isotope method for studying protein kinetics in pleural effusions in humans. Nucl Med Commun. 1992 Jun;13(6):432–439. doi: 10.1097/00006231-199206000-00043. [DOI] [PubMed] [Google Scholar]
- Vergnon J. M., Guidollet J., Gateau O., Ripoll J. P., Collet P., Louisot P., Brune J. Lactic dehydrogenase isoenzyme electrophoretic patterns in the diagnosis of pleural effusion. Cancer. 1984 Aug 1;54(3):507–511. doi: 10.1002/1097-0142(19840801)54:3<507::aid-cncr2820540320>3.0.co;2-4. [DOI] [PubMed] [Google Scholar]
- Whitaker D., Papadimitriou J. M., Walters M. N. The mesothelium: a cytochemical study of "activated" mesothelial cells. J Pathol. 1982 Mar;136(3):169–179. doi: 10.1002/path.1711360302. [DOI] [PubMed] [Google Scholar]
- Whitaker D., Papadimitriou J. M., Walters M. N. The mesothelium: a histochemical study of resting mesothelial cells. J Pathol. 1980 Nov;132(3):273–284. doi: 10.1002/path.1711320309. [DOI] [PubMed] [Google Scholar]
- Wiener-Kronish J. P., Matthay M. A., Callen P. W., Filly R. A., Gamsu G., Staub N. C. Relationship of pleural effusions to pulmonary hemodynamics in patients with congestive heart failure. Am Rev Respir Dis. 1985 Dec;132(6):1253–1256. doi: 10.1164/arrd.1985.132.6.1253. [DOI] [PubMed] [Google Scholar]