Blood Sampling: How To Draw Blood

Why Nurses Need to Learn How to Draw Blood

Obtaining blood samples or Blood Sampling, either via a venous stick or from a central line, is a critical nursing skill. Phlebotomy is essential for a variety of medical diagnoses, procedures, and tests. Without proper specimens, unhelpful or even harmful medical treatment could happen. Most nursing schools do not teach this skill due to legality issues. Students should study venipuncture in books and watch licensed nurses in clinical settings perform this task. In doing so, this will enable students to learn the basics prior to graduation. 

Even though most hospitals do have phlebotomy teams, it is still critical for nurses to learn these skills in order to provide the best patient care. In fact, the majority of intensive care units require their nurses to possess these skills. Phlebotomy teams generally only make rounds at specific times in hospital settings; therefore, if a lab test is ordered immediately, it could be the responsibility of the nursing staff to draw the specimen. 

Things Nurses Should Know About Drawing Blood

For nurses to be successful when drawing blood, there are several key things they must know, including, 

• Proper technique
• Proper safety standards to avoid a needle stick
• Vein placement in the arms
• Troubleshooting blood draws
• The rationale for blood draws

Steps on How to Draw Blood

Follow these steps to draw blood safely and effectively:

1. Prepare your equipment.

• Gather all the necessary equipment, such as alcohol swabs, bandages, collection tubes, gloves, needles, and tourniquet.
• Check expiration dates on tubes and needles.
• Arrange everything within easy reach.

2. Prepare the client.

• Always confirm the client’s identity using two unique identifiers, such as their name and date of birth, to prevent any errors in specimen collection.
• Explain the procedure to the client, addressing any concerns they might have. Ensure they’re comfortable and have given their consent.
• Make sure the client is comfortable with their arm extended and supported.

3. Select the venipuncture site and apply the tourniquet:

• Apply the tourniquet 3-4 inches above the chosen puncture site. This helps dilate the veins and make them more visible.
• Ask the client to make a fist without pumping.
• Gently feel for a visible, palpable vein using your fingers. This is usually the median cubital vein in the antecubital fossa (inner elbow).

4. Clean the skin.

• Cleanse the puncture site with an alcohol swab in a circular motion from the center outward.
• Allow the site to air dry to prevent alcohol contamination of the blood sample.

5. Insert the needle.

• Hold the needle at a 15–30-degree angle with the bevel up.
• Insert the needle gently into the vein at a slight angle.
• Once in the vein, attach the collection tube.

6. Collect the blood.

• Once blood flows into the collection tube, adjust the angle slightly to ensure proper flow.
• Fill the required tubes in the correct order of the draw.
• Gently invert tubes with additives to mix the blood.

7. Remove the tourniquet and withdraw the needle.

• Release the tourniquet once you establish blood flow.
• Withdraw the needle smoothly once the collection is complete.
• Immediately apply a clean gauze over the puncture site and ask the client to apply gentle pressure.

8. Label tubes and check the puncture site.

• Label the blood tubes accurately with client information.
• Check the puncture site for bleeding and apply a bandage if necessary.

9. Properly dispose of the needle.

• Safely dispose of the needle in an FDA-cleared sharps disposal container.
• Follow proper disposal protocols to prevent accidents and infections.

10. Document the procedure.

• Document the procedure in the client’s chart, noting any difficulties or reactions.
• Record the date, time, and amount of blood collected.

Drawing blood safely is a vital skill that enhances your nursing practice and the quality of client care. By following these guidelines and steps, you can perform this procedure with confidence and competence.

VENIPUNCTURE PROCEDURE

• Explain the procedure and reason for the blood draw to the patient.
• Identify the patient using two patient identifiers as mandated by the Institution
• Confirm the ordered tests and fill out the appropriate forms and labels.
• Check for any allergies or sensitivities with the patient regarding antiseptics, adhesives, or latex. True allergies should be identified on an allergy ID band, but sensitivities may not be reported at the time of patient admission. 
• Position the patient and hyperextend the patient’s arm.
• Perform good hand hygiene and don appropriate PPE. 
• Apply a tourniquet approximately 3-4 inches above the selected site. Closely monitor the arm to ensure that it is not applied too tight or for more than 1 minute. Reasons for concern would include numbness, tingling, change of color to blue or white, and/or extreme pain. 
• Ask the patient to make a fist and not pump the hand. This is a common misconception – pumping the hand does not increase venous circulation. 
• Prep the venipuncture site by cleansing the area with an alcohol prep pad for 30 seconds and allow to air dry for 60 seconds. Do not wave, fan, or blow on the area as this contaminates the area and leads to an increased risk for infection. 
• Grab the patient’s lower arm (below the site of the puncture, never above) firmly to draw the skin taut and anchor the vein from rolling. Insert the needle at a 15 to 30-degree angle into the vessel. 
• If properly inserted, blood should flash into the catheter. If this does not happen, then the needle has either not punctured the vein or the needle went through the vessel.
• If you do not get a flash of blood into the catheter, you can manipulate the catheter; however, do not entirely remove the catheter and re-stick using the same needle. 
• Attach the needed tubes or syringes to remove the proper volume of blood. Remove the tourniquet as the last amount of blood is drawn.
• Remove the needle from the patient’s arm and press down on the vessel with gauze. 
• Dispose of contaminated materials and needles in the designated hospital-approved containers.
• Label appropriate tubes at the bedside and place them into transport bags.
• Invert the tubes properly (depending on the type of tube).
• Deliver blood specimens to the laboratory promptly. If the blood is not delivered in a timely manner, it can cause haemolysis and skew the lab results. 

The World Health Organization’s Blood Draw Guidelines

The World Health Organization’s (WHO) best practice guidelines for blood draws include the following:

• Planning ahead
• Using an appropriate location
• Quality control

The overall purpose of establishing the guidelines is to, 

• Improve knowledge and awareness of the risks associated with phlebotomy among all health workers involved in the practice
• Increase safe practices and reduce blood-borne virus exposure and transmission
• Improve patient confidence and comfort
• Improve the quality of laboratory tests

The WHO has set forth the following standards of patient care for hospitals to adhere by: 

• Availability of appropriate supplies and protective equipment
• Availability of post-exposure prophylaxis (PEP)
• Avoidance of contaminated phlebotomy equipment
• Appropriate training in phlebotomy
• Cooperation on the part of patients
• Quality of laboratory sampling

They also identify dangerous and unsafe practices for blood draws including,

• Recapping used needles using two hands
• Recapping and disassembling vacuum-containing tubes and holders
• Reusing tourniquets and vacuum-tube holders that may be contaminated with bacteria and sometimes blood
• Working alone with confused or disoriented patients who may move unexpectedly contributes to needle sticks

REFERENCES

1. WHO Guidelines on Drawing Blood: Best Practices in Phlebotomy. Geneva: World Health Organization; 2010. 2, Best practices in phlebotomy. Available from: https://www.ncbi.nlm.nih.gov/books/NBK138665/
2. “Best Practices for Phlebotomy: A Systematic Review” (Journal of Patient Safety, 2020) Examines evidence-based guidelines for reducing blood collection errors.
3. “Phlebotomy Complications: A Review of Risk Factors and Prevention Strategies” (Journal of Clinical and Diagnostic Research, 2019) Investigates risk factors and prevention strategies for complications.
4. “Optimizing Venipuncture Techniques for Blood Collection” (Journal of Clinical Nursing, 2018) Evaluates effects of vein visualization, needle size, and insertion angle on blood collection.
5. “Comparison of Venipuncture Techniques: Straight vs. Butterfly Needle” (Journal of Medical Imaging and Radiation Sciences, 2019) Compares success rates, patient comfort, and complications.

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