Phlebotomy Tutorial

Phlebotomy is the drawing of blood in a clinical setting for clinical testing. It is a balancing act between the comfort of the patient and the quality of the sample(s). It is the job of the phlebotomist to maintain as much comfort for the patient while getting the appropriate sample(s) to complete the test(s) ordered. Phlebotomy should be attempted only after a formal study of anatomy and technique with an appropriate instructor, and while pursuing applicable certification and/or licensure.

Basic Approach

• Good phlebotomy begins with finding an appropriate draw site. Knowledge of the anatomy of the draw site is vital. A good phlebotomist is familiar with many different potential sites on the arm and hand. Remember that veins grow in response to pressure and follow no exact pattern. The basic idea is to look for a draw site twice as long as you actually perform the venipuncture.

Site Acceptability

• A good venipuncture site is one that is relatively close to the surface, not over a nerve or artery, and is "strong." "Strong" in this instance is defined as a vein that is healthy enough to push back when it is palpated. The bend of the arm is an ideal choice. The back of the hand is a secondary choice. The wrist is too close to arteries and veins to be a primary site. It can be used, but only with experienced supervision, usually a doctor. Placement of the tourniquet should be as much for the comfort of the patient as assisting in locating the site. For most draws in the arm, the tourniquet should be placed in the middle of the bicep, and should be applied in 30-second intervals. If it takes longer than 30 seconds to find an appropriate site, loosen the tourniquet briefly, then begin again.

Venipuncture

• The phlebotomist should be wearing gloves and taking other precautions against blood exposure as required by the facility in which he is working; the phlebotomist must also follow collection protocols as required by the facility in which he is working regarding patient identification, tube labeling, and so forth. The venipuncture site should be swabbed with alcohol. The bevel of the needle must be turned up. To facilitate a good flow into the collection tube, the phlebotomist must enter the skin at approximately the same angle as the bevel of the needle. Going straight down into the site is not an option. You enter the skin below the anatomical mark of the acceptable site, usually one quarter to one half an inch. Tensing the skin below the site is another technique to shorten the distance between the surface of the skin and the vein. Once the needle is in place, push on the collection device and look for the flash of blood into the tube. Remove the tourniquet. Continue with the collection as required. When the draw is finished, place a cotton ball or alcohol wipe on the venipuncture site and withdraw the needle. Press to stop the flow of blood, and cover with a bandage.

Missing the Site

• A common mistake is to move a needle you have already inserted in a lateral or side to side fashion to hunt for the vein. If a proper site has been found, there is no need for lateral motion. This is not only painful to the patient, but can corrupt the integrity of the sample. Move the needle back and forth in a straight line if you have missed the center of the site. If the draw gives you no sample, it is better to come out and start again.