Boris Shkolnik1, Marc A Judson1, Adam Austin1, Kurt Hu1, Melissa D'Souza2, Alexis Zumbrunn2, John T Huggins3, Recai Yucel4, Amit Chopra5. 1. Departments of Medicine, Pulmonary and Critical Care Medicine, Albany Medical Center, NY. 2. Departments of Medicine, Albany Medical Center, NY. 3. Ralph H.Johnson VA Medical Center, Division of Pulmonary, Critical Care, Allergy and Sleep Medicine, Medical University of South Carolina, Charleston, SC. 4. Department of Epidemiology and Biostatistics, School of Public Health, SUNY-Albany, NY. 5. Departments of Medicine, Pulmonary and Critical Care Medicine, Albany Medical Center, NY. Electronic address: chopraa1@mail.amc.edu.
Abstract
BACKGROUND: There are limited data examining the diagnostic accuracy of thoracic ultrasonography (TUS) in distinguishing transudative from exudative pleural effusions. RESEARCH QUESTION: What is the diagnostic accuracy of TUS in distinguishing transudative from exudative effusions in consecutive patients with pleural effusion? STUDY DESIGN AND METHODS: Consecutive patients who underwent TUS and subsequently a diagnostic thoracentesis with a pleural fluid analysis were identified. TUS images of the pleural effusions were interpreted by previously published criteria. We evaluated the diagnostic performance of TUS findings in predicting a transudative vs exudative pleural effusions and specific pleural diagnoses. RESULTS: We evaluated 300 consecutive pleural effusions in 285 patients. The pleural effusions were classified as exudative in 229 of 300 cases (76%). TUS showed anechoic effusions in 122 of 300 cases (40%) and complex effusions in 178 of 300 cases (60%). An anechoic appearance on TUS was associated with exudative effusions (68/122; 56%) as compared with transudative effusions (54/122; 44%). The presence of a complex-appearing effusion on TUS was highly predictive of an exudative effusion (positive predictive value of 90%). However, none of the four TUS characteristics were highly specific of a pleural diagnosis. INTERPRETATION: Thoracic ultrasonography is inadequate to diagnose a transudative pleural effusion reliably. Although the TUS findings of a complex effusion may suggest an exudative pleural effusion, specific pleural diagnoses cannot be predicted confidently.
BACKGROUND: There are limited data examining the diagnostic accuracy of thoracic ultrasonography (TUS) in distinguishing transudative from exudative pleural effusions. RESEARCH QUESTION: What is the diagnostic accuracy of TUS in distinguishing transudative from exudative effusions in consecutive patients with pleural effusion? STUDY DESIGN AND METHODS: Consecutive patients who underwent TUS and subsequently a diagnostic thoracentesis with a pleural fluid analysis were identified. TUS images of the pleural effusions were interpreted by previously published criteria. We evaluated the diagnostic performance of TUS findings in predicting a transudative vs exudative pleural effusions and specific pleural diagnoses. RESULTS: We evaluated 300 consecutive pleural effusions in 285 patients. The pleural effusions were classified as exudative in 229 of 300 cases (76%). TUS showed anechoic effusions in 122 of 300 cases (40%) and complex effusions in 178 of 300 cases (60%). An anechoic appearance on TUS was associated with exudative effusions (68/122; 56%) as compared with transudative effusions (54/122; 44%). The presence of a complex-appearing effusion on TUS was highly predictive of an exudative effusion (positive predictive value of 90%). However, none of the four TUS characteristics were highly specific of a pleural diagnosis. INTERPRETATION: Thoracic ultrasonography is inadequate to diagnose a transudative pleural effusion reliably. Although the TUS findings of a complex effusion may suggest an exudative pleural effusion, specific pleural diagnoses cannot be predicted confidently.