The Serum-Effusion Albumin Gradient in the Evaluation of Pleural Effusions: Results (1)

Sixty-one patients with pleural effusions were evaluated. One patient was excluded due to the diagnosis of empyema. Another patient was excluded because a simultaneous serum sample was not obtained. Of the 59 remaining patients, 37 were men, and 22 were women. The average age was 61 years (range, 19 to 84 years). Forty-one were defined as having exudates and 18 as transudates. In all cases the diagnosis reached after chart review was the same as that given by the primary physicians. The diagnoses are listed in the following tabulation:

Exudates    41

Malignant effusion    26

Parapneumonic    4

Postpericardiotomy syndrome    4

Pulmonary eml>olus    3

Rheumatoid arthritis    1

Pleuropericarditis    1

Peritonitis with effusion    1

Yellow nail syndrome    1

Transudates    18

Congestive heart failure    15

Nephrotic syndrome    2

Alcoholic ascites    1

Forty-four patients had an abnormally low serum albumin level (defined in our laboratory as less than 3.5 g/dl), 32 of whom were defined as having exudates and 12 as transudates.
The values for Lights criteria and the albumin gradient in all 59 patients are presented graphically in Figure 1. Applying the unpaired Mest to each criterion individually showed that the difference between exudate and transudate was statistically significant. Using an albumin gradient of 1.2 g/dl or less to indicate exudates allowed the best discrimination between them.

Figure 1. Results from 59 patients for effusion/serum LDH ratio (LDHK/LDHS), effusion LDH level (LDHE), effusion/serum protein ratio (proteinE/proteins), and serum-effusion albumin gradient (albumins-albuminE). Total exudates (solid circles) and transudates (open circles) are plotted for each criterion. Side bars refer to mean ±/l SD; p values were obtained using the unpaired f-test applied to data from each criterion separately.

Category: Pulmonary disease

Tags: albumin gradient, biopsy, diuretic therapy, exudates transudates, thoracentesis