February 1976

Characteristics of Pleural Effusions Associated With Pulmonary Embolism

Author Affiliations

From the Pauline and Adolph Weinberger Laboratory for Cardiopulmonary Research, Department of Internal Medicine, University of Texas Health Science Center, Southwestern Medical School, Dallas.

Arch Intern Med. 1976;136(2):159-162. doi:10.1001/archinte.1976.03630020019005

Pleural fluid characteristics were analyzed in 26 patients with pulmonary embolism. All determinations were highly variable. A bloody effusion occurred in 65%, while clear fluid was found in 35%. White blood cell counts had a wide distribution of values; polymorphonuclear leukocytes predominated in 61% and lymphocytes in 39%. Less than two thirds of tested specimens were exudates by standard criteria. Only 27% of effusions had the "typical" pattern of bloody appearance, polymorphonuclear predominance, and characteristics of an exudate. Roentgenographically evident infiltrates occurred in 62% and were correlated with bloody pleural fluid (P <.01), which suggests that infarction is not necessary for effusions to occur, but may account for a bloody appearance. The variability of these results indicates that there are no typical or diagnostic pleural fluid findings in pulmonary embolism.

(Arch Intern Med 136:159-162, 1976)