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Pericardial fluid gram stain

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Illustrations

Pericardial fluid stain
Pericardial fluid stain

Alternative Names    Return to top

Gram stain of pericardial fluid

Definition    Return to top

Pericardial fluid gram stain is a method of staining bacteria from fluid in the sac surrounding the heart to diagnose bacterial infections.

How the Test is Performed    Return to top

First, fluid is taken from the sac surrounding the heart. Some people may have a cardiac monitor placed before the test to check for heart disturbances. Patches called electrodes are put on the chest, similar to during an ECG. You might have a chest x-ray or ultrasound before the test.

The skin of the chest is cleaned with antibacterial soap. A trained physician, often a cardiologist, will take the sample.

A small needle is inserted into the chest between the ribs and into the pericardium, which is the thin sac that surrounds the heart. A small amount of fluid is taken out. You will feel pressure and some pain as the needle is inserted into the chest.

You may have an ECG and chest x-ray after the procedure. Sometimes the pericardial fluid is taken during open heart surgery.

A drop of the pericardial fluid is then placed in a very thin layer on a microscope slide -- this is called a smear. The specimen is stained with a series of stains, together called a gram stain. The stained smear is then examined under the microscope for the presence of bacteria.

The color, size, and shape of the cells help make it possible to identify the bacteria.

How to Prepare for the Test    Return to top

You will be asked not to eat or drink anything for several hours before the test. A chest x-ray or ultrasound may be done before the test to identify the area of fluid collection.

How the Test Will Feel    Return to top

You will feel some pressure and discomfort when fluid is removed from the sac surrounding the heart. Your doctor should be able to give you enough pain medicine so that the procedure does not hurt very much.

Why the Test is Performed    Return to top

The test is performed when the doctor suspects an infection of the heart, or if you have a pericardial effusion with an unknown cause.

Normal Results    Return to top

Results are normal when no organisms are found in the gram stain test.

What Abnormal Results Mean    Return to top

If bacteria are present, you may have an infection of the pericardium or heart. Further testing, such as bacterial culture, can identify the specific organism causing the infection. Sometimes blood testing can help with the diagnosis.

Risks    Return to top

There is a risk of puncturing the heart or the lung with this procedure. Introducing infection into the area is another rare, but potential, risk.

Considerations    Return to top

Other tests may be performed on the pericardial fluid sample.

Update Date: 7/25/2008

Updated by: A.D.A.M. Editorial Team: David Zieve, MD, MHA, Greg Juhn, MTPW, David R. Eltz. Previously reviewed by Arnold L. Lentnek, M.D., Division of Infectious Disease, Kennestone Hospital, Marietta, GA. Review provided by VeriMed Healthcare Network (11/12/2007).

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The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed physician should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. Copyright 1997-2008, A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.