Pleural fluid analysis

How the test is performed:

A sample of pleural fluid is obtained by the procedure of thoracentesis. The specimen is examined for color, glucose and protein content, cellular composition, the presence of malignant (growing worse - resisting treatment) cells, and the presence of microorganisms.

How to prepare for the test:

Adults:
There is no special preparation. Do not cough, breathe deeply, or move during the test to avoid injury to the lung. A chest X-ray may be performed before and/or after the test.

Infants and children:
The physical and psychological preparation you can provide for this or any test or procedure depends on your child's age, interests, previous experience, and level of trust. For specific information regarding how you can prepare your child, see the following topics as they correspond to your child's age:

• infant test or procedure preparation (birth to 1 year)
• toddler test or procedure preparation (1 to 3 years)
• preschooler test or procedure preparation (3 to 6 years)
• schoolage test or procedure preparation (6 to 12 years)
• adolescent test or procedure preparation (12 to 18 years)

How the test will feel:

You will be positioned sitting on the edge of a chair or bed with your head and arms resting on a table. The skin around the insertion site is disinfected and the area is draped. A local anesthetic is injected into the skin. The thoracentesis needle is inserted above the rib into the pocket of fluid. There will be a stinging sensation when the local anesthetic is injected, and a sensation of pressure when the needle is inserted into the pleural space. Inform your health care provider if you develop shortness of breath.

Why the test is performed:

The test is performed to determine the cause of a pleural effusion.