Lesson 4 – Venepuncture Techniques

For then next few lessons we will be going into actual blood taking starting with

Venepuncture is a common medical procedure used to obtain blood samples for diagnostic testing, transfusions, or other medical purposes. It involves puncturing a vein with a needle to collect blood. This lesson will provide step-by-step instructions for the venepuncture procedure and guidance on identifying suitable veins for blood collection.

I. Identifying Suitable Veins for Blood Collection:

Before performing a venipuncture, it is crucial to identify suitable veins for blood collection. Here are some tips for locating appropriate veins:

1. Examine the Arm:
   • Look for visible veins on the surface of the arm.
   • The most commonly used veins for venipuncture are the median cubital vein, cephalic vein, and basilic vein. These veins are usually easy to locate and access.
2. Palpation:
   • Gently palpate the arm to feel for veins that are suitable for venipuncture.
   • Veins should feel resilient, springy, and have a slight bounce when pressed lightly.
   • Avoid veins that feel hard, cord-like, or roll away when touched.
3. Consider the Vein Size:
   • Choose veins that are large enough to accommodate the needle for blood collection.
   • Veins with a diameter of 0.4 to 0.6 cm (0.15 to 0.25 inches) are generally preferred.
4. Accessibility:
   • Choose veins that are easily accessible and not too close to nerves or arteries.
   • Avoid areas with visible bruising, swelling, or skin lesions.

II. Step-by-Step Instructions for Venipuncture Procedure:

Once suitable veins have been identified, follow these step-by-step instructions for performing a venipuncture:

1. Gather the necessary supplies:
   • Sterile gloves
   • Alcohol swabs
   • Tourniquet
   • Blood collection tubes
   • Needle and syringe or vacuum tube system
   • Adhesive bandage or gauze pad
2. Prepare the patient:
   • Explain the procedure to the patient and address any concerns or questions.
   • Ensure the patient is comfortable and seated or lying down, with their arm extended and supported.
3. Perform hand hygiene:
   • Wash your hands thoroughly with soap and water or use hand sanitizer.
4. Put on gloves:
   • Open the packaging of sterile gloves and put them on, ensuring a snug fit.
5. Apply the tourniquet:
   • Select an appropriate tourniquet and wrap it around the upper arm, 3 to 4 inches above the intended venipuncture site.
   • Tighten the tourniquet enough to restrict venous blood flow without causing discomfort to the patient.
6. Cleanse the site:
   • Use an alcohol swab to clean the intended venipuncture site in a circular motion, starting from the center and moving outward.
   • Allow the site to dry completely before proceeding.
7. Prepare the needle and syringe/tube system:
   • Assemble the needle and syringe or connect the vacuum tube system as per the manufacturer’s instructions.
   • Ensure the appropriate size of the needle is selected based on the patient’s vein and the intended blood collection method.
8. Stabilize the vein:
   • Apply gentle pressure below the intended venipuncture site to stabilize the vein and prevent it from rolling.
9. Perform the venipuncture:
   • Hold the needle at a shallow angle (15 to 30 degrees) to the skin surface.
   • Insert the needle smoothly and quickly into the vein, keeping it in line with the direction of the vein.
   • Observe for a flashback of blood in the needle hub, indicating successful entry into the vein.