Lara Milevoj Kopcinovic*1, Jelena Culej2. Pleural, peritoneal and pericardial effusions â a biochemical approach. Biochemia Medica 2014;24(1):123-37. The pathological accumulation of serous fluids in the pleural, peritoneal and pericardial space occurs in a variety of conditions. Since patient management depends on right and timely diagnosis, biochemical analysis of extravascular body fluids is considered a valuable tool in the patient management process.