Phlebotomy is the act of taking a blood sample from the vein of a patient for laboratory examination and analysis. It is a critical part of the health care world. Phlebotomists are specially trained in this technique and are able to procure blood from several different veins in the body. Blood is usually drawn using the veins of the arm, although the hand veins may also be used.
The antecubital fossa is the area of the arm near the elbow. This area is in the front of and below the bend of the arm at the elbow. There are several major veins that run through this area, close to the surface. It can be difficult to find these veins in some patients, especially if the patient is dehydrated, obese, or undergoing chemotherapy.
Three Primary Veins
There are three veins most commonly used in venipuncture, or phlebotomy. They are the cephalic, median cubital, and basilic veins. These three veins are found in the antecubital area. The cephalic vein is found on the lateral, or outside, of the arm. The median cubital vein, the preferred one to use, is found close to the center, and the basilic vein is located on the inner, or medial part of the antecubital area.
The median cubital vein is the preferred vein for phlebotomy because it is usually larger than the other veins and more stationary. Veins can move, or roll, which makes it more difficult to perform phlebotomy. The median cubital is typically well anchored, which makes it less likely that the patient will feel pain during phlebotomy, or bruise afterwards.
Other Antecubital Veins
The cephalic and basilic veins are only used if the medial cubital vein is not felt or is damaged in some way. The cephalic vein is the second choice usually, since it is fairly well anchored. This is often the only vein that can be felt in patients who are obese. The basilic vein is kept as a last choice option. It rolls more easily and runs directly over a nerve and an artery, making it a more dangerous and painful area to use.
At times, none of the veins of the antecubital fossa will be felt. They also may not be able to be used due to intravenous placement or injury. Hand veins may be used if it is not possible to use the antecubital veins. Veins of the hand and wrist are usually close to the surface, but they are prone to movement and rolling. Using these veins tends to be more painful for the patient, since there are nerves running through the hand as well. If using these veins, it is important to anchor the vein with your hand, holding it in place, when you are drawing the blood.
Veins of the legs, feet, and ankles cannot be used without specific permission from a physician. Usually if these veins are to be used, the physician will draw the blood. There is the potential for blood clots to form when these veins are used.