Pericardial Effusion

A pericardial effusion is excess fluid within the pericardial sac. It may be a stable, incidental finding or may rapidly impair cardiac filling and produce cardiac tamponade. The decisive question is not simply how large the effusion looks; it is whether the fluid has raised intrapericardial pressure enough to reduce venous return, diastolic filling and tissue perfusion. For the RN, a new effusion creates three immediate questions: How much fluid is present? Is tamponade developing? What disease caused it? A patient with a slowly enlarging large effusion may remain relatively stable, whereas a small haemorrhagic effusion after trauma or myocardial rupture can cause sudden cardiovascular collapse.