Q: After thoracentesis, patient's pleural fluid reported no glucose in pleural fluid. Which 2 conditions should be considered strongly?
Answer: A low pleural fluid/serum glucose ratio less than 0.5 easily narrows the differential diagnosis to rheumatoid pleurisy, empyema, malignant effusion, tuberculous pleurisy, lupus pleuritis and esophageal rupture. Of all, pleural fluid in rheumatoid pleurisy and empyema many times comes with no glucose. This is due to decreased transport of glucose from blood to pleural fluid.