To help diagnose the cause of inflammation of the pericardium and/or fluid accumulation around the heart
Sampling pericardial fluid only for analysis is rarely done because other less invasive tests exist to help determine the cause of the fluid accumulation around the heart. However, pericardial fluid removed for therapeutic reasons (pericardial tamponade) is often routinely sent for analysis. especially if a bacterial or malignant cause is suspected or the cause of a large collection is obscure.
A sample of fluid collected by a doctor from the pericardial sac using a procedure called a pericardiocentesis (see Common questions above)
Pericardial fluid is a liquid that acts as a lubricant for the movement of the heart. It is found in small quantities between the two layers of the pericardium. Pericardial fluid is produced by mesothelial cells in the membranes and acts to reduce friction as the heart pumps blood.
A variety of conditions and diseases can cause inflammation of the pericardium (pericarditis) and/or excessive accumulation of pericardial fluid (pericardial effusion) for example; inflammation, congestive heart failure, autoimmune disorders or metastatic cancer.
Pericardial fluid analysis comprises a group of tests used to determine the cause: red and white blood cell counts and differential, cytology, Gram stain, fungal culture and acid fast staining for tuberculosis. Biochemical tests that may be performed are pH, glucose, lactate dehydrogenase (LD) and total protein.
A sample of fluid is collected from the pericardial sac by a doctor with a syringe and needle using a procedure called a pericardiocentesis (see Common questions). This is usually done in a special laboratory under guidance by echocardiography or X-ray imaging and ECG monitoring.
No special preparation is usually needed
Pericardial fluid analysis is sometimes used to help diagnose the cause of inflammation of the pericardium called pericarditis and/or fluid accumulation around the heart (pericardial effusion). However, just as important for diagnosis are the ECG, echocardiography, blood markers of inflammation (CRP, ESR, white blood cell count), troponin (myocardial damage) and chest X-ray or CT scan.
Microscopic examination - Normal pericardial fluid has small numbers of white blood cells (WBCs) but no red blood cells (RBCs) or microorganisms. Laboratories may examine drops of the pericardial fluid and/or use a special centrifuge (cytocentrifuge) to concentrate the fluid’s cells at the bottom of a test tube. Samples are placed on a slide, treated with special stain, and an evaluation of the different kinds of cells present is performed.
Infectious disease tests - routine tests for microorganisms if infection is suspected:
Increased amounts of pericardial fluid can restrict the movement of the heart. Cardiac tamponade is a condition that reflects pericardial fluid buildup to the point that pressure on the heart prevents it from filling normally. Rapid fluid buildup can be a medical emergency, causing heart failure and death. When fluid accumulates slowly, the pericardial sac stretches and symptoms gradually worsen.
Pericardiocentesis is the removal of pericardial fluid from the pericardial sac with a needle and syringe. An intravenous (IV) line may be started and the person may be given medications prior to the sample collection. The patient is positioned lying down. A local anaesthetic is applied, then the doctor inserts the needle into the space between the ribs (fifth to sixth intercostals space) on the left side of the chest and into the pericardial sac and removes a fluid sample. An ultrasound scan may be used to help guide the needle.
Pericardiocentesis is lifesaving in cardiac tamponade, which is the usual reason it is done although sometimes it is performed for diagnosis. Ideally pericardiocentesis, guided by utrasound is done in a cardiac catheterisation laboratory with ECG monitoring but in emergency situations it can be performed at the bedside.
Pleural fluid analysis, peritoneal fluid analysis, Gram stain, susceptibility testing, protein, albumin, glucose, AFB smear and culture
Conditions: Liver disease, kidney disease, bleeding disorders, autoimmune disorders, congestive heart failure, systemic lupus erythematosus, tuberculosis
RCPA manual: Pleural/pericardial fluid examination
Better Health Channel: Pericarditis
National Heart Lung and Blood Institute: Heart inflammation (USA)
MedlinePlus Medical Encyclopedia: Pericarditis
American Heart Association: What is Pericarditis?
18/5/16 Up-To-Date – Diagnosis and treatment of pericardial effusion, and Emergency pericardiocentesis
Last Review Date: February 11, 2020