Sputum Test

Sputum Test

A test to find and characterize bacteria or fungus that infect the lungs or breathing passages is a sputum culture. Sputum is a viscous fluid that is formed in the airways around the lungs. Sputum is collected and deposited in a sterile container before being delivered to the lab for analysis.

Sputum/Phlegm Colors and Meanings

Sputum can be many colors and consistency, and these can help define certain conditions. For example:

• Clear sputum is normal
• White/gray sputum can be normal
• Dark yellow/green sputum -
  • A type of white blood cells known as neutrophils have a green color to them. These types of white blood cells are attracted to the scene of bacterial infections, and therefore bacterial infections of the lower respiratory tract, such as pneumonia, may result in producing green sputum
• Brown sputum -
  • Brown sputum due to the presence of tar, is sometimes found in people who smoke.
• Pink sputum -
  • Pink, especially frothy pink sputum may come from pulmonary edema - a condition in which fluid and small amounts of blood leak from capillaries into the alveoli of the lungs.
• Bloody sputum -
  • Bloody sputum, even just a tract of blood tinged sputum, should always be evaluated. Coughing up blood can be serious, and is the first sign of lung cancer in 7% of people. Even 1 to 2 teaspoons of coughed up blood is considered a medical emergency.

Sputum Contents

• Sputum is made up from secretions from cells lining the respiratory tract, dead cells, foreign matter that is breathed into the lungs, and white blood cells and other immune cells.
• In infections, bacteria may also be present in sputum, and sometimes blood as well in the case of lung cancer, trauma to the respiratory tract, damage to the airways, and pulmonary edema.

Conditions With Increased Sputum

Some conditions that result in increased production of sputum include:

• Chronic bronchitis - Chronic bronchitis results in increased sputum, and in fact, the criteria for a diagnosis include a daily cough productive of sputum
• Bronchiectasis
• Pulmonary Edema
• Overproduction of sputum can be caused by smoking and exposure to air pollution

Sputum Tests

Sputum may be analyzed in the lab to determine its contents and more. Tests include:

• Sputum culture - When performing a sputum culture, a sample of sputum is placed in a growing medium, and the existence of growth is checked. This could be done to identify the specific bacterial strain that is responsible for pneumonia. The lab can then perform additional tests to discover which antibiotic is most effective against that bacteria once the strain of bacteria has been identified.
• Sputum for tuberculosis - A sputum sample may be obtained to look for tuberculosis.
• Sputum cytology - Sputum samples are examined under a microscope in sputum cytology. This might be done to check for indications of cancerous cells or TB. Sputum cytology was once thought to be a useful method for screening for lung cancer, but it is not. However, the presence of cancer cells may be a sign of lung cancer. The site of the malignancy will next need to be determined by additional testing.

References

• Mandal, G. (August 2013). A Textbook of Adult Health Nursing (2nd ed.). Dilllibazar kathmandu: Makalu publication house. Retrieved August 2013
• www.webmd.com/lung/sputum-culture
• https://labtestsonline.org/understanding/analytes/sputum-culture/tab/sample/
• www.thetruthabouttb.org/do-i-have-tb/testing-for-tb/
• emedicine.medscape.com/article/2119232-overview
• www.emedicinehealth.com › home › topics az list
• www.healthline.com/health/routine-sputum-culture