Venipuncture Using the Evacuated Tube System The evacuated tube system is the method used most

commonly for obtaining blood. It is fast and relatively safe, and allows for multiple tubes to be filled with one invasive procedure.

TASK

Successfully perform a venipuncture using the evacu- ated tube system. The process must be completed within 5 minutes.

CONDITIONS

• Hand-washing supplies and/or alcohol-based hand sanitizer

• Disposable gloves

• Tourniquet

• 70% isopropyl alcohol

• Double-pointed multi-sample needle

• Evacuated tube holder

• Laboratory requisition form or labels with specified test

• Evacuated tubes

• 2 x 2 gauze pads

• Adhesive bandage or wrap

• Test tube rack

• Biohazardous sharps container

• Biohazardous disposal bag CAAHEP/ABHES STANDARDS

CAAHEP Standards

I.P.I.2: Perform Venipuncture I.A.I.1: Apply critical thinking skills in performing patient assessment and care III.P.III.3: Select appropriate barrier/personal protective equipment (PPE) for potentially infectious situations

ABHES Standards

• Medical Office Laboratory Procedures: Collect, label and process specimens: Perform venipuncture

• Medical Office Clinical Procedures: Apply principles of aseptic techniques and infection control

• Medical Office Clinical Procedures: Use Standard Precautions

Procedure Rationale

1. Gather the requisition form and/or labels for the

blood draw, and greet the patient. Identify your- self appropriately.

2. Wash hands (if they are visibly soiled) or apply

hand sanitizer. Allow hands to dry completely.

3. Verify the identity of the patient by asking for his

or her name and at least one other unique identi- fier (such as the patient’s birth date). Compare this information to the requisition form or labels.

4. Verify whether dietary restrictions were followed,

and time of last medication dose, if needed.

5. Have the patient sit in the phlebotomy chair with

appropriate arm support, and extend his or her arm to expose the antecubital area.

The requisition or labels are necessary to collect the correct type of specimen. It is always correct practice to identify yourself to the patient.

Clean hands stop the spread of infection. Hands should be completely dry before attempting to apply gloves, or it will be difficult to put the gloves on the wet hands.

Patient identification must always be verified using at least two unique factors.

Many laboratory tests require fasting specimens or other dietary restrictions. Drug dosage times are es- pecially important for appropriate interpretation of the laboratory results.

The arm should be supported for the venipuncture process, and the antecubital area will be the first area that is considered for the blood draw.

Chapter 8 Collection and Processing of Blood Samples 155

6. Apply gloves.

7. Apply the tourniquet approximately 3 in. above

the antecubital area (or above the wrist if a hand draw is necessary) and select an appropriate draw site using palpation. Use the tips of the ring finger and middle finger in a gentle probing motion as the antecubital area is examined. An appropriate vein will feel flexible and firm. Do not allow the tourniquet to remain on the arm for more than 1 minute.

8. While palpating, have the patient make a fist, but

do not allow the patient to pump his or her hand.

9. If an appropriate site is not identified on the first

arm, examine the other arm. If the antecubital area is not appropriate on either arm, examine the back of the hands for other opportunities.

10. Once an appropriate site is selected, determine the

direction of the vein; is it running straight up and down or at an angle across the arm? Establish a visible landmark (a mole or dimple in the skin, etc.) for reference.

11. Have the patient open the hand to relax the fist

until the tourniquet is reapplied.

12. Remove the tourniquet.

Gloves are required for procedures in which there is reasonable anticipation of exposure to blood or other potentially infectious materials.

The tourniquet needs to be placed high enough that it will not block the venipuncture site. Only blood vessels that can be palpated should be used for venipuncture; just looking at them is not sufficient. The thumb should never be used to feel for a vein, as there may be a pulse felt from the thumb that can be misleading. The thumb is also not as sensitive as the fingers.

Procedure Rationale

Pumping the hand can cause erroneous test results due to hemoconcentration.

It is important to choose the best site before inserting the needle. If the first arm examined doesn’t provide a vein that is appropriate, check the other arm. If necessary, the back of the hands may be con- sidered as a blood draw site.

The needle must be inserted in such a way that it follows the direction of the vein for the best chance of success. A landmark is helpful so that the chosen venipuncture site can be identified after cleaning the area.

Relaxing the hand will help the blood to flow normally as the site is prepared.

A tourniquet may not stay on the arm for more than 1 minute, or hemoconcentration may result.

13. Apply 70% isopropyl alcohol to the area in a

circular motion with the draw site at the center of the circle. Allow the site to air-dry.

14. As the alcohol is drying, assemble the necessary

supplies.

a. Choose a needle of appropriate size and attach

it to the evacuated tube holder. Do not remove the cap that covers the long end of the needle until right before the skin is to be punctured.

b. Arrange the necessary tubes for the tests

ordered within easy reach of your nondomi- nant hand, and have them set up in the correct order of draw.

c. Verify that the tubes are not expired and that

the anticoagulant is placed away from the rub- ber stopper within the tube. (You may need to shake the tube lightly to get the anticoagulant to move away from the stopper.) Check for any obvious defects in the tubes.

15. Verify that gauze pads and an adhesive bandage are

within reach. Extra tubes should also be close by so that they can be used if necessary.

16. Once the alcohol is dry, reapply the tourniquet.

Do not repalpate the venipuncture site, or if absolutely necessary, clean the end of the gloved finger with alcohol before touching the site.

17. Have the patient make a fist.

18. Remove the cap to expose the end of the needle to

be inserted into the arm. Do not allow this needle to touch anything before piercing the skin.

70% isopropyl alcohol will kill most of the bacterial contaminants on the surface of the skin. Never blow or fan the site to speed up the drying process, as this recontaminates the clean area.

Supplies need to be close by for ease of use and patient safety.

This should always occur in the presence of the patient so that he or she is assured that the needle is sterile. The cap should not be removed until it is ready to be used to minimize the risk of contamina- tion or possible injury. Needle sizes may vary according to the needs of the patient and the policy of the facility.

The tubes may be laid out on the counter near the pa- tient, or a small tube rack may work well for this purpose.

Use of an expired tube may result in a loss of vacuum and an unsuccessful blood draw. Potential crossover of anticoagulant from one tube to another should be minimized as much as possible. Defective (such as cracked or chipped tubes) should be discarded im- mediately.

The gauze pads and adhesive bandages need to be ready for use immediately when the needle is removed from the skin. If the phlebotomist feels that there may be a chance that the vacuum is exhausted in the first tube, using a second one that is nearby may allow the venipuncture to be successful.

If the site is touched after cleansing, it will need to be cleaned again before the venipuncture can begin.

Forming a fist may help with the visualization of the veins once the tourniquet is reapplied.

Touching this needle to any surface before it pierces the skin will cause contamination and possible introduction of bacteria into the vein.