- Phlebotomy is a medical technique in which a needle is inserted temporarily into a vein to withdraw blood for diagnostic or therapeutic (treatment) purposes.
- Phlebotomy is also called bloodletting, blood drawing, or venipuncture.
- A person who is qualified to perform a phlebotomy is called a phlebotomy technician or phlebotomist. Although a phlebotomy may be performed by a doctor or nurse, a phlebotomist is a professional specifically qualified to perform this procedure.
Why is a phlebotomy done?
A phlebotomy may be done for the diagnosis or treatment of diseases. A diagnostic phlebotomy is generally done for blood sampling for lab analysis and short-term blood transfusion through a butterfly needle.
A therapeutic phlebotomy may be done for the treatment of certain medical conditions such as
- hemochromatosis (a genetic condition in which iron salts are deposited at various sites in the body),
- certain liver diseases,
- sickle cell disease (a disorder in which the red blood cells become brittle), and
- polycythemia vera (a type of blood cancer in which the bone marrow makes an excess of RBCs).
The site of a phlebotomy is generally the veins at the elbow or back of the hand.
How is a phlebotomy done?
A phlebotomy is generally performed as a quick outpatient procedure.
Before the test:
- No special preparations are generally needed before a phlebotomy.
- Some lab tests (such as blood sugar estimation) may need fasting for 8-12 hours before the phlebotomy.
- The doctor who prescribed you the test will explain to you how to prepare before the phlebotomy.
- The phlebotomist may ask if you underwent a phlebotomy before and whether you had any complications after that.
- They may also ask if you have any latex allergy (the tourniquet or band used during the procedure is made up of latex). They will also address your concerns related to the procedure.
- They may ask if you are on any long-term medications. The phlebotomist will then take your written consent before the procedure.
During the procedure:
- You will be asked to sit or lie in a comfortable position with your arm resting over a cushioned flat surface.
- The phlebotomist will wash their hands with soap and water before putting on a pair of single-use gloves.
- A phlebotomy is generally performed with an evacuated tube system (such as a Vacutainer; BD, Franklin Lakes, NJ) or a syringe and a needle or winged butterfly needle device.
- The phlebotomist will tie a latex band called a tourniquet about 10 cm above the chosen site.
- Generally, the non-dominant hand is chosen for a phlebotomy.
- They will ask you to lower your arm while clenching and releasing the fist repeatedly for about 15-30 seconds to engorge the veins and make them more prominent. They will palpate the potential phlebotomy site to check that the vein is healthy (soft and bouncy and refills after being depressed).
- The phlebotomist will clean the selected site with a disinfectant using a cotton swab. The area is allowed to dry for about 30 seconds.
- They will then insert a needle into the vein, collect the blood sample, and release the tourniquet before removing the needle.
- After removing the needle, it is disposed of immediately in a biohazard container. You may feel a little prick when the needle is inserted.