This group comprised 56 patients (39 men and 17 women) aged 61 ± 18 years. In 33 cases, pleural effusion was associated with pneumonia diagnosed on the basis of compatible clinical and radiologic findings with no signs of cardiac insufficiency, and in nine with pulmonary thromboemboli diagnosed by arteriography or by perfusion pulmonary gammagraphy.
Pleural fluid and blood samples were taken at the same time from fasting patients. Pleural biopsies were performed in all cases with Cope’s needle except those in which it was suspected that the effusion was a transudate.
Biochemical parameters were determined with a selective discrete multichannel analyzer (Genesis 21-1L). Total protein concentrations (g/dl) were measured by the biuret method with no serum blank; LDH (IU) by the kinetic UV method recommended by the Scandinavian Society for Clinical Chemistry;” and cholesterol (mg/ dl) by the enzymatic colorimetric method CHOD-PAP For 40 transudate patients aged 70±14.5 years, 37 neoplastic exudate patients aged 65.5 ±14.0 years, 23 tuberculous exudate patients aged 43 ± 20 years, and 30 miscellaneous group patients aged 62 ± 20 years (130 patients in all), low^density lipoprotein (LDL) cholesterol was estimated by applying the formula of Friedewald et al to high-density lipoprotein (HDL) cholesterol values obtained after precipitation with phosphotungstic acid and magnesium chloride.
A Useful Parameter for Distinguishing between Pleural Exudates and Transudates (3)