RESUMEN
GOALS: To analyze the pleural fluid factors that might cause spontaneous bacterial empyema (SBEM) in patients with cirrhotic hydrothorax. BACKGROUND: Pathogenic mechanism of SBEM of cirrhotic patients is probably similar to that of spontaneous bacterial peritonitis, but local factors affecting pleural fluid have not been studied. STUDY: Determination of C3, C4, and opsonic activity levels of pleural fluid in a cohort of patients with pleural effusions of different causes. RESULTS: Forty-eight patients had hepatic hydrothorax; 8, heart failure and 45, exudates (9, tuberculosis; 21, malignancies; 10, other). Of the 48 cirrhotic patients, 15 developed SBEM on admission. The pleural fluid of cirrhotic patients showed significantly lower levels of total protein, complement, and opsonic activity than did the fluids of patients with other causes of SBEM. Patients who developed SBEM had lower concentrations of pleural fluid total protein and C3 and had a higher Child-Pugh score than patients who did not develop the infection. CONCLUSION: Cirrhotic patients with hepatic hydrothorax have lower pleural fluid opsonic activity and C3 levels than those found in the pleural fluid of patients with other causes. Patients who develop SBEM have lower levels of pleural fluid C3, pleural fluid total protein, and a higher Child-Pugh score than those who do not develop SBEM.