Ultrasounic Elastography-guided Pleural Biopsy Followed by As-needed Medical Thoracoscopic Pleural Biopsy Versus Immediate Medical Thoracoscopic Pleural Biopsy for the Diagnosis of Pleural Effusion

Exclusion Criteria

• •1. Significantly bleeding risk, including uncorrectable coagulopathy (such as INR \>1.5, platelet count \<50×109 /L) or the need for ongoing anticoagulant/antiplatelet therapy that cannot be safely paused;
• •2. Hemodynamic instability;
• •3. Refractory hypoxemia despite supplemental oxygen;
• •4. Any severe concurrent illness or cardiopulmonary compromise that, in the investigator's judgment, makes either procedural sedation (for thoracoscopy) or a bedside biopsy (for UEPB) unsafe;
• •5. Pleural effusion conclusively identified as a transudate;
• •6. Pregnancy or lactation;
• •7. Any condition that, in the investigator's judgment, would compromise protocol compliance or follow-up.