Drawing blood, or phlebotomy, is a critical procedure in healthcare that requires precision, care, and adherence to strict safety protocols. Whether you are a healthcare professional or in training, understanding the steps and best practices for drawing blood is essential to ensure both the safety of the patient and the accuracy of the blood samples.
Preparing for the Procedure
Before initiating the blood draw, it is crucial to prepare both the equipment and the patient. Gather all necessary equipment, including alcohol swabs, bandages, collection tubes, gloves, needles, and a tourniquet. Ensure that all supplies are within easy reach and check the expiration dates of the tubes and needles to avoid any contamination or errors[1][4].
Confirm the patient’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 patient, address any concerns they might have, and ensure they are comfortable and have given their consent. Position the patient in a comfortable seated or lying down position with their arm extended and supported to prevent fainting and make the blood draw easier[1][4].
Selecting the Venipuncture Site
The selection of the venipuncture site is a critical step. The median cubital vein in the elbow crease is often the preferred site, but the cephalic or basilic veins can also be used. Avoid areas that appear swollen, scarred, or bruised, as these can complicate the procedure and affect the quality of the blood sample[4].
Apply a tourniquet around the upper arm, a few inches above the selected puncture site. The tourniquet should be snug enough to slow blood flow but not so tight that it causes discomfort. It is important to monitor the time and not leave the tourniquet on for more than two minutes to avoid altering the blood composition and affecting test results[4].
Cleaning and Preparing the Site
Clean the selected site thoroughly with an alcohol pad for about 30 seconds and allow it to air dry. This step is vital for preventing infections and ensuring the sterility of the procedure. Additionally, ensure your hands are clean by washing them or using hand sanitizer, and wear gloves and other protective gear to maintain safety for both you and the patient[1][4].
Inserting the Needle
Hold the vein steady below the insertion point and insert the needle at a slight angle, typically between 15–30 degrees with the bevel up. Once the needle is in the vein, you will see blood entering the collection tube. Attach the collection tube to the needle and ensure it is filling properly. Adjust the angle of the needle slightly if necessary to maintain proper blood flow[1][4].
Collecting the Blood Sample
Collect the blood into the required tubes in the correct order to avoid mixing up the additives. Fill each tube until it is about three-quarters full. When filling the last tube, remove the tourniquet to ensure accurate test results. Gently invert tubes with additives to mix the blood properly[1][4].
Removing the Needle and Applying Pressure
Once the collection is complete, release the tourniquet and withdraw the needle smoothly. Immediately apply a clean gauze over the puncture site and ask the patient to apply gentle pressure to stop any bleeding. This helps prevent bruising and other complications[1][4].
Post-Procedure Care
After the needle is removed, secure the gauze with tape or a bandage. Mix and label all appropriate tubes according to the laboratory requirements and dispose of contaminated materials and sharps properly. Update the patient’s medical records with the details of the procedure and any observations[1][3].
Most Important Facts About Drawing Blood
Prepare Equipment and Patient: Gather all necessary equipment and confirm the patient’s identity. Explain the procedure and ensure patient comfort and consent[1][4].
Select Appropriate Venipuncture Site: Choose a site like the median cubital vein, avoiding swollen, scarred, or bruised areas[4].
Apply Tourniquet Correctly: Apply the tourniquet snugly but not too tightly, and remove it within two minutes to avoid affecting blood composition[4].
Clean the Site: Clean the site with an alcohol pad and let it air dry to prevent infections[1][4].
Insert Needle Correctly: Insert the needle at a 15–30-degree angle with the bevel up and attach the collection tube once in the vein[1][4].
Collect Blood in Correct Order: Fill tubes in the correct order to avoid mixing additives, and remove the tourniquet when filling the last tube[1][4].
Remove Needle and Apply Pressure: Withdraw the needle smoothly and apply gentle pressure to the puncture site to stop bleeding[1][4].
Post-Procedure Care: Secure the gauze, mix and label tubes, dispose of sharps, and update patient records[1][3].
