NEW-ONSET PLEURAL EFFUSION
A 67-year-old white female who was treated for exacerbation of her chronic obstructive pulmonary disease returned a week later with the same shortness of breath. This time she had new-onset bilateral pleural effusions that were not present the first time. Thoracentesis revealed transudative fluid. Two-dimensional echocardiography performed at her first visit showed ejection fraction 80% with diastolic failure. Albumin was low (2.2 g/dL), and B type natriuretic peptide was 23 pg/mL. Urinalysis was negative for protein. Could diastolic dysfunction cause anasarca?
—Tadron L. Wilson, MD, Cookeville, Tenn.
The evaluation of a new-onset pleural effusion often presents challenges, as seen in this case. Although many laboratory criteria exist to distinguish exudative and transudative pleural fluids, the laboratory data must always be interpreted in the context of the patient’s clinical condition. Transudative effusions result from imbalances between hydrostatic and oncotic forces in the pleural space. Classically, congestive heart failure, hypoalbuminemia, and hepatic cirrhosis account for the majority of transudative effusions. I doubt that diastolic dysfunction alone accounts for your patient’s effusions. Some diseases that are said to “classically” produce exudative effusions may rarely present with pleural effusions that appear transudative; these include hypothyroidism, pulmonary embolism, sarcoid, and lymphatic obstruction from malignancy. Additional evaluation likely will be needed, and both pulmonary and cardiologic evaluations may be required.
—R. Steven Tharratt, MD, MPVM (114-23)