Pleural fluid culture

AsseyMethod: Microb Culture
Abbrevation: Pleural fluid culture
Sector: Microbiology
SampleType: Pleural fluid
S.Vol: -
Transport: 0.5 hrs. at 2-8˚c˚
Storage: 2 hrs. at 2-8˚c
Test Name: Pleural fluid culture
Normal Range: -

This test is related to
Why Get Tested?

To help diagnose the cause of inflammation of pleurae (pleuritis, pleurisy), accumulation of fluid in the pleural space (pleural effusion), or possible malignancy

When To Get Tested?

When a doctor suspects that someone with chest pain, coughing, and/or difficulty breathing has a condition associated with pleuritis and/or pleural effusion

Sample Required?

A volume of pleural fluid is collected by a doctor using a procedure called thoracentesis, in part to relieve pressure and for diagnostic purposes

Test Preparation Needed?


What is being tested?

Pleural fluid is found in the pleural cavity and serves as a lubricant for the movement of the lungs during inhalation and exhalation. It is derived from a plasma filtrate from blood capillaries and is found in small quantities between the layers of the pleurae – membranes that cover the chest cavity and the outside of each lung.

A variety of conditions and diseases can cause inflammation of the pleurae (pleuritis) and/or excessive accumulation of pleural fluid (pleural effusion). Pleural fluid analysis is a group of tests used to help find the cause of the problem. There are two main reasons why fluid may collect in the pleural space:

  • Fluid may accumulate in the pleural space because of an imbalance between the pressure within blood vessels—which drives fluid out of blood vessels—and the amount of protein in blood—which keeps fluid in blood vessels. The fluid that accumulates in this case is called a transudate. This type of fluid usually involves both lungs and is often a result of either cirrhosis of the liver or congestive heart failure.
  • Fluid accumulation may be caused by injury or inflammation of the pleurae, in which case the fluid is called an exudate. It usually involves one lung and may be seen in infections (pneumonia, tuberculosis, sarcoidosis), malignancies (lung cancer, metastatic cancer, lymphoma, mesothelioma), rheumatoid disease, or systemic lupus erythematosus.

Differentiation between the types of fluid is important because it helps diagnose the specific disease or condition. Doctors use an initial set of tests (cell count, albumin and appearance of the fluid) to distinguish between transudates and exudates. Once the fluid is determined to be one or the other, additional tests may be performed to further pinpoint the disease or condition causing pleuritis and/or pleural effusion.

How is the sample collected for testing?

A sample of pleural fluid is collected by a doctor with a syringe and needle using a procedure called thoracentesis.

Is any test preparation needed to ensure the quality of the sample?

No test preparation is needed.