Review Question - QID 108670

A 67-year-old G0P0 woman presents to the emergency room with a 5 day history of progressive shortness of breath and nonproductive cough. She denies chest pain, palpitations, or fever but reports a 3-month history of weight gain, abdominal distention, decreased appetite, and constipation. She has had no abdominal pain or changes in her urinary habits. She is a retired schoolteacher who has never smoked. Her temperature is 98.9°F (37.2°C), blood pressure is 124/80 mmHg, pulse is 81/min, respirations are 15/min, and oxygen saturation on room air is 91%. On exam, the patient is visibly struggling to breathe and has difficulty speaking complete sentences. She has markedly decreased lung sounds in the right lower lung field and a distended abdomen with fluid shift. Chest radiograph is shown in Figure A. A thoracentesis is performed and pleural fluid analysis as well as corresponding serum values are shown below:

Total protein, serum: 6 g/dL
Total protein, pleural fluid: 4.1 g/dL

Lactate dehydrogenase, serum: 76 U/L
Lactate dehydrogenase, pleural fluid: 68 U/L

Cytology of the pleural fluid is pending. What is the most appropriate next step in management?