- A 57-year-old woman with a medical history of renal pelvis staghorn calculi presented to the emergency department with nonproductive cough and dyspnea 8 days following left percutaneous nephrolithotripsy. The patient appeared distressed and tachypneic. Her temperature was 36.7 °C, blood pressure was 147/86 mm Hg, pulse was 93 beats/min and O2 saturation was 94% in ambient room air. Physical examination revealed a decrease in tactile fremitus and breath sounds over the left chest. An anterior–posterior chest radiograph disclosed a left pleural effusion (Fig. 1a) and bed-side thoracocentesis yielded a straw-colored fluid with strong ammonia odor (Fig. 1b). Laboratory analysis of the fluid revealed pH of 8.4, glucose of 93 mg/dL, protein of 1.37 gr/dL, and lactate dehydrogenase (LDH) of 522 units/L. The corresponding plasma levels of protein and LDHwere 6.8 g r/dL (norm: 6.6–8.3) and 484 units/L (norm: 230–480). Furthermore, pleural fluid and plasma creatinine levels were 5.0 mg/dL and1.24 mg/dL (norm: 0.67–1.10) respectively. Computerized tomography demonstrated the intervention tract traversing the left renal pelvis and adjacent pleural space (Fig. 1c and d).