Venipuncture Procedure and Requirements Explained

Venipuncture Procedure is the collection of blood from a vein, usually for laboratory testing, is done through venipuncture and performed by a phlebotomist. Although most professionals in the medical field can draw blood, a phlebotomy technician specializes in the procedure and is trained accordingly.

Routine Venipuncture Explained

Although venipuncture is primarily concerned in collecting blood specimens, there are other steps involved in the entire procedure. There are best practices that must be observed as well.

Materials Required For Veinpuncture

1. Needles used depend on the procedure that will be undertaken. Options include safety needles that are 22g or less, butterfly needles in 21g or less and syringes.

2. Blood collection tubes are used when drawing blood in predetermined volume. These vacuum tubes come with different additives necessary for collecting blood specimen for a specific type of tests. Additives are identified through the color of the rubber stopper.

3. Tourniquets, preferably latex-free, must be used.

4. Sharps disposal container is a puncture proof container that ensures safe disposal of needles. It must be acceptable by OSHA and marked Biohazardous.

5. Other materials needed are antiseptic, 2×2 gauze or cotton balls, and bandages or tape.

Pre-Venipuncture Procedure

1. Identify a patient through the requisition form or patient ID. In-room patients who are asleep must be woken up. When dealing with psychiatric patients, a registered nurse must be on standby to help.
2. Explain the procedure to patients and reassure them about the amount of blood to be drawn for testing.
3. Assemble equipment required, wash hands and then put on gloves.

Performing the Test

1. Ask the patient to extend the arm until a straight line from shoulder to wrist is formed.
2. Choose the appropriate site for venipuncture. Most frequently used veins are median cubital, basilica and cephalic. Never draw blood on an artery or from the feet, unless specified.

• When veins are hard to find, palpate, tap veins, massage the chosen site, apply heat or have the patient hand down his arm. If none of these works, collect blood from wrist or hand instead.
• When choosing a site, check for extensive scarring or healed burns. Do not draw blood from areas of hematoma or from an arm with fistula, cannula or vascular graft.

3. Prepare and clean the site with antiseptic or other germ-killing medicine.
4. Place the tourniquet 3 to 4 inches above the venipuncture site, making it swell with blood.
5. Hold the patient’s arm and place a thumb below the chosen site to anchor the vein.
6. Ask the patient to form a fist so the vein will pop up, making it more prominent.
7. Insert the needle to the vein at a 30-degree angle or less. Make sure the needled moves along the vein.
8. Collect blood into an airtight tube or vial that is attached to the needle.
9. Once blood flow is established, or a sufficient amount of blood is collected, release the tourniquet. Make sure to do this before withdrawing the needle and before the tourniquet has been in place for two minutes or more.
10. Gently remove the needle and use a clean gauze or cotton to apply gentle pressure on the venipuncture site. Ensure that the patient keeps his arm extended and raised, while holding the gauze. Tell him not to bend his arm to avoid the occurrence of hematoma.
11. Dispose the syringe and needle as a unit into a sharps container.

What if blood sample cannot be obtained?

• Try to reposition the needle with causing the patient intense pain
• Replace the collection tube as the vacuum may have disappeared
• Loosen the tourniquet

Only two attempts are allowed per single patient, and probing must be avoided as much as possible.