ETS Draw
Preparing for Venipuncture
Blood specimen collection from an antecubital vein using the evacuated tube system (ETS) is a crucial procedure in phlebotomy. To ensure patient safety and specimen integrity, the following steps are essential:
Patient Identification and Consent
Confirm the patient's identity through two identifiers (e.g., name and date of birth) to ensure accurate specimen collection.
Obtain informed consent explaining the procedure's purpose, risks, and benefits to address any patient concerns and foster cooperation.
Sanitation and Personal Protective Equipment (PPE)
Prior to venipuncture, thoroughly sanitize your hands with an alcohol-based hand sanitizer or soap and water for at least 20 seconds.
Don appropriate PPE, including gloves, to prevent contamination and adhere to OSHA regulations.
Positioning and Vein Selection
Proper positioning and vein selection are critical for a successful venipuncture:
Patient Arm Positioning
Position the patient's arm downward, extending from shoulder to wrist in a straight line, for optimal vein visibility and to minimize the risk of reflux, which can affect sample quality.
Tourniquet Application
Apply a tourniquet approximately 3-4 inches above the antecubital area to engorge the veins, increasing visibility.
Ensure that the tourniquet is snug but not overly tight to avoid discomfort and venous occlusion, which can cause hemoconcentration.
Enhancing Vein Visibility
Ask the patient to clench their fist gently to enhance blood flow to the veins while ensuring the veins do not roll.
Vein Palpation and Selection
Palpate to choose a large, resilient vein. Ideal choices include:
Median Cubital Vein: First choice due to its size and central location.
Cephalic or Median Cephalic Veins: Second choices, often more lateral.
Basilic Vein: Use only if necessary, as it is more prone to complications due to its proximity to nerves and arteries.
Release the tourniquet and instruct the patient to open their fist before cleaning the site to restore normal blood flow.
Site Preparation
Proper site preparation is critical for reducing infection risk:
Cleaning the Site
Clean the selected venipuncture site with a 70% isopropyl alcohol antiseptic pad. Use a circular motion from the center outward to minimize contamination.
Allow the site to air dry completely to enhance antiseptic effectiveness and minimize discomfort during needle insertion.
Equipment Preparation
Selecting and preparing the right equipment is vital:
Collection Equipment
Select appropriate collection tubes according to the tests ordered, ensuring they are within the expiration date.
Attach the needle securely to the ETS holder, and position the first tube in the holder if preferred.
Reapply the tourniquet prior to proceeding with the venipuncture.
Needle Handling and Insertion
Safe needle handling and insertion technique are paramount:
Needle Inspection
Uncap the needle and inspect it for defects (e.g., bent, damaged). Discard any flawed needles to ensure patients' safety.
Patient Arm Stability
Ensure the patient's arm remains in the downward position to facilitate proper tube filling and to avoid reflux caused by contact with the stopper.
Venous Anchor Technique
Anchor the vein by pulling the skin taut near the insertion site to reduce pain and ease needle insertion.
Insertion Technique
Warn the patient about the slight pinch they may feel upon needle insertion. Insert the needle quickly at a 30-degree angle, bevel side up, using a smooth motion. Advance until a decrease in resistance is felt, indicating entry into the vein.
Blood Collection
Proper technique ensures optimal specimen quality:
Verify Needle Position
Once blood flow begins, confirm that the needle is properly positioned within the vein and allow the tube to fill completely.
Release the tourniquet and remind the patient to open their fist as soon as blood flow is established to avoid complications such as hemolysis.
Order of Draw
Follow the CLSI (Clinical and Laboratory Standards Institute) order of draw to prevent additive carryover.
Tube Mixing
Fill each tube until the normal vacuum is exhausted to ensure the correct blood-to-additive ratio and immediately invert tubes (3-8 gentle inversions) depending on the type of additive used, ensuring proper mixing is achieved, especially for anticoagulant tubes.
Ending the Venipuncture
Properly concluding the venipuncture is essential for patient safety:
Needle Removal
Use your free hand to pick up the gauze and smoothly remove the needle without lifting or pushing down to minimize discomfort and prevent formulating a hematoma.
Safety Activation
Immediately activate the needle safety feature to prevent unintentional needle stick injuries.
Pressure Application
Apply gauze over the puncture site and apply pressure, allowing the patient to assist if they are able. Encourage them to maintain pressure for a few minutes.
Disposal
Dispose of the needle and holder as a single unit in a sharps container, per OSHA regulations, to avoid exposure risks.
Post-Collection Procedures
Proper post-collection care is crucial for patient wellbeing:
Labeling
Accurately label collection tubes with patient information (name, date of birth, time of collection, type of specimen). Double-check to ensure matching with requisition forms.
Site Assessment
Assess the collection site for bleeding for 5-10 seconds; continue applying pressure to help control any bleeding until it stops.
If bleeding persists beyond 5 minutes, promptly notify the appropriate personnel for further evaluation.
Post-Collection Instructions
Once bleeding has stopped, apply an appropriate bandage and instruct the patient to keep it in place for a minimum of 15 minutes to promote healing and protect the puncture site. Advise them to avoid heavy lifting or strenuous activity for at least an hour following the procedure.
Material Disposal
Discard all used materials (needles, tubes, gauzes) in accordance with biohazard waste procedures; ensure gloves are removed aseptically, followed by handwashing to maintain hygiene