Pleural Effusion

Abstract
A 70-year-old man with an 80-pack-year history of smoking and a history of congestive heart failure presents with increasing shortness of breath. He also has aching chest pain on the right side that worsens with deep inspiration. He is afebrile. The chest radiograph reveals asymmetrical bilateral pleural effusions, with more fluid on the right. How should this patient be evaluated?