Phlebotomy
Phlebotomy is the practice of drawing blood from a patient for various medical tests, including microbiology, cytology, and fluid analysis. It is typically performed by licensed phlebotomists who follow strict protocols to ensure accuracy and safety. Blood is collected using color-coded tubes that contain specific additives, and the order of drawing these tubes is crucial to avoid contamination. The procedure generally involves applying a tourniquet, selecting a suitable vein (most commonly in the arm), cleaning the skin, and then inserting a needle for venipuncture.
While venipuncture is the most common method, blood can also be collected via fingerstick or from an artery, depending on the situation. The procedure is relatively quick and usually takes just a few minutes. Safety precautions, such as wearing gloves and using sterile equipment, are essential to minimize risks, which are generally low. However, some patients may experience minor side effects like light-headedness. Overall, phlebotomy is a vital component of modern medical diagnostics, facilitating the accurate assessment of a patient's health.
Subject Terms
Phlebotomy
- ALSO KNOWN AS: Venipuncture
- ANATOMY OR SYSTEM AFFECTED: Arms, blood, blood vessels, circulatory system
DEFINITION: The collection of blood specimens for analysis
Indications and Procedures
Phlebotomy is performed to acquire blood samples for microbiology, cytology, analysis, or other testing. Blood collection tubes are drawn in a specific order to avoid cross-contamination of additives in tubes designed for specific tests. Collection tubes are color-coded according to the additives (if any) contained within them. An essential component of the procedure is the accurate labeling of tubes with information identifying the patient, which is often confirmed several times to ensure accuracy. Blood collection should be carried out only by a licensed phlebotomist.
A temporary tourniquet is applied to the arm three to four inches above the selected puncture site, the skin is cleaned with an or iodine wipe, and then a needle is inserted into a vein (venipuncture). Blood can also be collected from an artery or fingerstick, if appropriate. Often, the skin is palpated, and the vein is traced with a finger, or the arm may be massaged until a superficial vein is readily apparent. After one or more tubes of blood (typically about ten milliliters in volume) are collected, a gauze sponge is applied until the bleeding stops, and then an adhesive bandage is applied. The tourniquet is immediately removed after the last tube to be drawn starts to fill. The entire procedure takes only a few minutes.
When smaller volumes of blood are required, collection can be accomplished by a simple fingerstick on the third or fourth finger of the nondominant hand, using a sterile lancet. The first drop of blood is wiped away, and then blood is collected into a capillary tube while the finger is gently massaged. After the fingerstick procedure, the patient normally is instructed to hold a small gauze pad over the puncture site for a few minutes to stop the bleeding. For blood collection on a newborn baby or infant, the heel is the recommended puncture site.
Uses and Complications
Phlebotomy is a routine procedure with minimal risks. Many doctor's offices have trained phlebotomists who take precautions to protect themselves and the patient from exposure to blood-borne diseases and to prevent the occurrence of infection. These precautions include the use of rubber or latex gloves and only new, sterile disposable tubes and needles. Most frequently, blood is taken from the larger and fuller median cubital and cephalic of the arm; wrist and hand veins can also be acceptable. Certain areas are avoided in venipuncture: extensive scar tissue from burns or injury, the site of a previous mastectomy, regions of hematoma, sites of and blood transfusion, or devices, and extremities suffering from edema. Some patients may experience light-headedness or faintness during blood collection; to prevent accidents, the patient remains seated during the brief procedure.
Bibliography
Garza, Diana, and Kathleen Becan-McBride. Phlebotomy Handbook: Blood Specimen Collection from Basic to Advanced. 10th ed., Pearson, 2020.
Hoeltke, Lynn B. The Complete Textbook of Phlebotomy. 6th ed., Cengage, 2024.
Berman, Jacob. “Venipuncture.” MedlinePlus, US Natl. Lib. of Medicine, NIH, 20 June 2023, medlineplus.gov/ency/article/003423.htm. Accessed 14 Jan. 2025.
McCall, Ruth E., and Cathee M. Tankersley. Phlebotomy Essentials. 7th ed., Jones & Bartlett Learning, 2021.
Nelson, Angela. Reviewed by Carmelita Swiner. “What is Phlebotomy?” WebMD, www.webmd.com/a-to-z-guides/what-is-phlebotomy. Accessed 14 Jan. 2025.
“Phlebotomists.” Occupational Outlook Handbook, Bureau of Labor Statistics, US Dept. of Labor, 29 Aug. 2024, www.bls.gov/ooh/healthcare/phlebotomists.htm. Accessed 14 Jan. 2025.