Venipuncture is the technical term used to describe the routine removal of blood from a vein for subsequent laboratory testing. You may undergo this procedure as part of the observation or diagnosis of a wide range of medical conditions. The specifics of any given venipuncture can vary significantly based on a doctor's instructions and the particular type of blood testing required.
Basics
Health professionals who perform venipunctures are called phlebotomists. They typically begin a venipuncture by identifying an appropriate vein in your body. Veins commonly used for this purpose include the veins in the crook of your arm and the small veins on the back of your hand. After identifying a vein, the person drawing blood will clean the sample site with an antiseptic wipe. If blood is drawn from the inside of your elbow, an elastic band placed on your upper arm will help fill the target vein with blood.
Drawing Blood
To draw blood during a routine venipuncture, your health care provider will attach a hollow needle to an airtight tube or vial, then insert the needle into the sample site. Blood drawn from your vein will flow through the needle into the attached receptacle. After obtaining the necessary amount of blood, your provider will release the elastic band on your arm, remove the needle and place some type of material on the puncture site to help stop any residual bleeding.
Lab Testing
After performing a venipuncture, your health care provider will typically label your sample vial and send it to a laboratory for testing. In addition to your personal information, a color-coded top on the sample vial will indicate to the laboratory the specific testing your doctor has ordered. After testing has been completed, the laboratory will relay the results to your doctor, who will then interpret the lab's findings and discuss them with you.
Considerations
As an alternative to venipuncture, you may have a blood sample drawn from your finger with a device called a fingerstick. If your infant or young child needs to provide a blood sample, his doctor can use a small needle called a lancet to draw blood directly from the skin. In some cases, your doctor may ask you to fast, modify your medication usage or avoid certain drinks or foods before a venipuncture. Potential risks associated with venipuncture include difficulty drawing a sample from your vein, a blood accumulation under your skin called a hematoma, lightheadedness, fainting, excessive bleeding and infection at the testing site. Consult your doctor for more information.
