Pericardial fluid

Pericardial fluid is secreted by the serous membrane on the pericardious sac on the outside of the heart. The pericardial cavity contains between 15 and 50ml of pericardial fluid. It is similar to the serous fluid that is found in the brain for cushioning and ability to move semi-freely.

A pericardial effusion is the presence of excessive pericardial fluid. While small effusions occur in many clinical scenarios and are not necessarily dangerous, large and rapidly accumulating effusions may cause cardiac tamponade, a life-threatening complication.

Ben-Horin et al (2005) studied the composition of pericardial fluid in patients undergoing open heart surgery. They found it was relatively rich in lactate dehydrogenase, low in protein and high in lymphocytes and monocytes. They state that these findings may alter diagnostic criteria for abnormal effusions.

Reference

 * Ben-Horin S, Shinfeld A, Kachel E, Chetrit A, Livneh A. The composition of normal pericardial fluid and its implications for diagnosing pericardial effusions. Am J Med 2005;118:636-40. PMID 15922695.