Pericardiocentesis

Pericardiocentesis (PCC), also called pericardial tap, is a medical procedure where fluid is aspirated from the pericardium (the sac enveloping the heart). The pericardium is a fibrous sac surrounding the heart composed of two layers: an inner visceral pericardium and an outer parietal pericardium. The area between these two layers is known as the pericardial space and normally contains 15 to 50 mL of serous fluid. This fluid protects the heart by serving as a shock absorber and provides lubrication to the heart during contraction. The elastic nature of the pericardium allows it to accommodate a small amount of extra fluid, roughly 80 to 120 mL, in the acute setting. However, once a critical volume is reached, even small amounts of extra fluid can rapidly increase pressure within the pericardium. This pressure can significantly hinder the ability of the heart to contract, leading to cardiac tamponade. If accumulation of fluid is slow and occurs over weeks to months, the pericardial sac can tolerate several liters of additional fluid without substantially hindering the ability of the heart to pump. Indications for performing pericardiocentesis can be divided into those that are therapeutic (i.e. treating tamponade) and those that are diagnostic (i.e. pericardial fluid analysis). Pericardiocentesis can be used to diagnose and treat cardiac tamponade. Cardiac tamponade is a medical emergency in which excessive accumulation of fluid within the pericardium (pericardial effusion) creates increased pressure. This prevents the heart from filling normally with blood. This can critically decrease the amount of blood that is pumped from the heart, causing obstructive shock, which can be lethal. The removal of the excess fluid reverses this dangerous process, and is often the first treatment for cardiac tamponade due to its speed. Pericardiocentesis can relieve the symptoms of pericarditis. There may be a normal amount of pericardial fluid, but inflammation still causes compression of the heart. Removal of some of this fluid reduces pressure on the heart.