BACK TOTOP Browse A-ZSearchBrowse A-ZABCDEFGHIJKLMNOPQRSTUVWXYZ0-9 E-mail FormEmail ResultsName:Email address:Recipients Name:Recipients address:Message: Print-FriendlyBookmarksbookmarks-menuPleural fluid Gram stainGram stain of pleural fluidThe pleural fluid Gram stain is a test to diagnose bacterial infections in the lungs. How the Test is Performed A sample of the fluid can be removed for testing. This process is called thoracentesis. One test that can be done on the pleural fluid involves placing the fluid onto a microscope slide and mixing it with a violet stain (called a Gram stain). A laboratory specialist uses a microscope to look for bacteria on the slide.ThoracentesisThoracentesis is a procedure to remove fluid from the space between the lining of the outside of the lungs (pleura) and the wall of the chest....Read Article Now Book Mark Article Gram stainA Gram stain is a test used to identify bacteria. It is one of the most common ways to quickly diagnose bacterial infection in the body.ImageRead Article Now Book Mark Article If bacteria are present, the color, number, and structure of the cells are used to identify the type of bacteria. This test will be done if there is concern that a person has an infection involving the lung or the space outside the lung but inside the chest (pleural space). How to Prepare for the Test No special preparation is needed before the test. A chest x-ray will probably be done before and after the test.DO NOT cough, breathe deeply, or move during the test to avoid injury to the lung. How the Test will Feel You will feel a stinging sensation when the local anesthetic is injected. You may feel pain or pressure when the needle is inserted into the pleural space.Tell your health care provider if you feel short of breath or have chest pain. Why the Test is Performed Normally, the lungs fill a person's chest with air. If fluid builds up in the space outside the lungs but inside the chest, it can cause many problems. Removing the fluid can relieve a person's breathing problems and help explain how the fluid built up there.The test is performed when the provider suspects an infection of the pleural space, or when a chest x-ray reveals an abnormal, usually large collection of pleural fluid. The Gram stain can help identify the bacteria that might be causing the infection.Chest x-rayA chest x-ray is an x-ray of the chest, lungs, heart, large arteries, ribs, and diaphragm.ImageRead Article Now Book Mark Article Normal Results Normally, no bacteria are seen in the pleural fluid.Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your doctor about the meaning of your specific test results. What Abnormal Results Mean You may have a bacterial infection in the lining of the lungs (pleura).Open ReferencesReferencesMartin GJ, Friedlander AM. Bacillus anthracis (Anthrax). In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases. 9th ed. Philadelphia, PA: Elsevier; 2020:chap 207.Millington TM, Finley DJ. Pleural effusion and empyema. In: Kellerman RD, Rakel DP, eds. Conn's Current Therapy 2021. Philadelphia, PA: Elsevier 2021: 892-894.AllVideoImagesTogPleural smear - illustration A pleural smear examines a sample of pleural fluid under the microscope to detect for abnormal organisms. The test is performed when infection of the pleural space is suspected or when an abnormal collection of pleural fluid is noticed by chest x-ray.Pleural smearillustrationPleural smear - illustration A pleural smear examines a sample of pleural fluid under the microscope to detect for abnormal organisms. The test is performed when infection of the pleural space is suspected or when an abnormal collection of pleural fluid is noticed by chest x-ray.Pleural smearillustrationA Closer Look Pneumonia(In-Depth) Tests for Pleural fluid Gram stain Pleural fluid Gram stainGram stainRelated Information Review Date: 11/27/2020 Reviewed By: Denis Hadjiliadis, MD, MHS, Paul F. Harron, Jr. Associate Professor of Medicine, Pulmonary, Allergy, and Critical Care, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team. The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. © 1997- © 1997- All rights reserved. A.D.A.M. content is best viewed in IE9 or above, Firefox and Google Chrome browser.Content is best viewed in IE9 or above, Firefox and Google Chrome browser.