Venipuncture: Equipment and Supplies

Objectives of Venipuncture

• To list, describe, and explain the equipment and supplies for blood specimen collection via venipuncture.
• To define associated terms and abbreviations.
• To list and describe the components of the Evacuated Tube System (ETS) and syringe system.
• To explain how each system works, and when to use each system and its components.
• To demonstrate knowledge of blood collection additives, their chemical compositions, and functions.
• To describe ETS tube stopper color coding for identifying the presence/absence of additives.
• To connect additives and stopper colors with lab departments/tests.
• To list the order of draw and explain its importance.

General Blood Collection Equipment and Supplies

• A blood-drawing station includes a table for supplies and a special chair.
• Phlebotomy chairs should be comfortable, have adjustable armrests, prevent falls, and may recline or have adjustable height. Ergonomic and bariatric models are available.
• Phlebotomists often visit patients in busy environments like hospitals, necessitating portable equipment.
• Handheld phlebotomy equipment carriers are available in multiple sizes and designed to hold supplies for multiple draws, especially for STAT or emergency situations; best when few samples are needed.
• Phlebotomy carts hold more supplies, better for collecting many samples during "sweeps" and are easy to maneuver, though can be bulky and a source of nosocomial infections; best practice is to leave them outside the room/area.
• When using a phlebotomy cart, only bring the equipment needed by using a small tray.
• Adequate stocking of carts and trays is a key phlebotomist duty.

Gloves and Glove Liners

• Gloves are required by CDC/HICPAC and OSHA during phlebotomy.
• A new pair of gloves must be used for each patient.
• Acceptable glove materials are nonsterile, disposable latex, nitrile, neoprene, polyethylene, and vinyl.
• Latex gloves are not commonly used due to latex allergies and are not recommended.
• Avoid using powdered gloves, as they are associated with lung problems, allergies, and hypersensitivities.
• A good glove fit is crucial for tactile sensitivity.
• Glove liners or barrier hand creams can be used if gloves cause allergies or dermatitis reactions.

Hand Hygiene

• Hands must be decontaminated before putting on gloves and after glove removal.
• Both hand washing and alcohol-based hand sanitizers are acceptable for hand hygiene.
• Use hand sanitizers only if hands are not visibly soiled.
• Always wash visibly soiled hands with soap and water.

Antiseptics and Disinfectants

• Antiseptics prevent or inhibit microorganism growth, but don't necessarily kill them.
• Antiseptics are safe on human skin and prevent sepsis.
• 70% isopropyl alcohol is the most common antiseptic for routine blood collection.
• Other antiseptics include iodine, benzalkonium chloride, chlorhexidine gluconate, and hydrogen peroxide.
• Disinfectants remove or kill microorganisms on surfaces and instruments.
• Disinfectants, unlike antiseptics, are unsafe for use on human skin.
• Reusable medical equipment requires sterilization, as disinfectants do not kill spores.

Hand Sanitizers

• Hand sanitizers are alcohol-based rinses, gels, and foams that are used in place of handwashing.
• Hand sanitizers are effective if hands are not visibly soiled.
• Handwashing and hand sanitizers are important tools for maintaining asepsis.

Gauze, Bandages, Slides and Pens

• Clean 2 × 2-in gauze pads or cotton balls are used to apply pressure after blood collection.
• Some pads have fluid-proof backing.
• Avoid using cotton balls as they can stick to the site of the draw.
• Bandages are applied over the collection site once bleeding stops; paper, cloth, or knitted tape may be used over folded gauze.
• Always check for patient allergies to adhesives and do not use self-adhesive bandages on infants under 2 years old (choking hazard).
• Slides may be needed for blood smear preparation.
• Labeling requires a permanent, non-smearing pen.

Watches and Patient ID Equipment

• A watch with a second hand or a portable digital clock is needed to time the draw.
• The watch should be easy to disinfect.
• Many phlebotomists use a watch that pins to their scrubs.
• Patient identification equipment and barcode readers are used to correctly label tubes at the patient's bedside in many facilities.

Sharps Containers and Biohazard Bags

• Used needles, lancets, and other sharp objects must be immediately discarded into a sharps container.
• Sharps containers are rigid, puncture-resistant, leakproof, disposable, and clearly labeled with the biohazard symbol and a locking lid.
• Never overfill sharps containers; dispose of them when they are 2/3 full to prevent biohazard exposure.
• Biohazard bags are leakproof bags marked with a biohazard label and used to transport blood and other specimens. They often have an external pouch to keep paperwork free of contamination.

Vein Locators and Tourniquets

• Vein-locating devices use transillumination via high-intensity LED or infrared light to highlight veins in subcutaneous tissue by hemoglobin absorption.
• Vein-locating devices can assist the phlebotomist in locating hard to find veins.
• A tourniquet restricts blood flow and is applied around the patient's arm to inflate veins; it should restrict venous flow without affecting arterial flow.
• Tourniquets should not be left on for over 1 minute, and most are stretchable disposable straps.

Needles

• Needles for venipuncture are sterile, disposable, and designed for single use only.
• Needle types include multi-sample, hypodermic, and winged infusion (butterfly) needles.
• Needle parts include the bevel, shaft, hub, and lumen.
• Gauge is the diameter of the needle's lumen; the higher the gauge, the smaller the diameter.
• Needles are color-coded by gauge (25, 23, 22, 21).
• A 21-gauge 1 ¼ inch needle is commonly used for phlebotomy.
• Needle lengths of 1- and 1.5-in are common for venipuncture.
• The correct needle size should be selected for each phlebotomy; needles that are too big will collapse a vein, too small will hemolyze the final sample.

Tube Holders and the ETS

• Safety features on tube holders (hubs) can be attached to the needle.
• The evacuated tube system (ETS) blood flows directly from the vein into a collection tube.
• The ETS system prevents exposure to air or outside contaminants, allowing for collection of numerous tubes with a single venipuncture.
• ETS components include a multi-sample needle, tube holder, and evacuated tubes.

Multi-Sample Needles and Needle and Holder Units

• Multi-sample needles allow for multiple tubes to be collected during a single venipuncture; they have a double-pointed needle with a threaded part that screws into the holder.
• The tube end of the needle has a retractable sleeve to prevent leakage.
• Multi-sample needles come with and without safety features; a safety holder must be used if there are no safety features.
• Needle and holder units have the needle and holder permanently attached.
• After use, needle and holder units require that the used equipment be disposed of together and never be removed from the needle and reused.

Evacuated Tubes

• Evacuated tubes are used with both ETS and syringe methods and come in a range of sizes and volumes.
• The size used depends on patient age, the volume of blood needed for testing, and the size and condition of the patient's vein.
• Tubes are available in glass and plastic; plastic is the preferred option for safety, and OSHA regulates their use.
• Evacuated tubes must always be inspected before use.
• The tube vacuum creates negative pressure, drawing an exact volume of blood into the tube; additive tubes contain a substance (e.g., anticoagulant), while nonadditive tubes have no added substance (rare).
• Stoppers are made of rubber or plastic, color-coded to indicate the type of additive. Expiration dates for the additive and vacuum are printed on the tube label.

Syringe Systems and Blood Collection Sets

• Syringe systems are an alternative for patients with small or difficult veins and are no longer typically used for phlebotomy.
• Syringe needles are 1–1.5 inches long and must have a resheathing feature to draw blood.
• Syringes consist of a barrel, plunger, and needle and can be graduated.
• A syringe transfer device allows for safe blood transfer into tubes without a syringe needle or removing the stopper.
• Syringes do not contain additives, so blood must be transferred promptly to the correct tube using a transfer device to reduce the chance of needle sticks. Never transfer blood from a syringe to a tube without a transfer device!
• Winged infusion sets, also known as "butterflies," are blood collection sets that require automated in-vein retraction. They are effective for small or difficult veins commonly found in hands/elderly/pediatric patients.
• Butterflies connect either to an evacuated tube holder or a syringe, with shorter lengths for shallower angles. Common gauges are from 25-21 gauge,.
• Non-winged blood collection sets have VANISHPOINT to eliminate exposure.
• Combination systems have a complete system for blood collection which has blood collection tube and collection apparatus combined in single unit. Specimen can be collected by evacuated tube or syringe and are available with regular or butterfly-style needles and safety devices.

Blood Collection Additives

• Additives are anything added to a tube other than the stopper or silicone coating.
• Most tubes contain additives to prevent/encourage clotting or preserve blood components.
• Additives are not interchangeable.
• If an anticoagulant is added, the result is whole blood.
• Some whole blood samples are used as is and some are centrifuged to obtain plasma for testing.
• If a clot activator is the additive, the blood will clot and the tube must be centrifuged to obtain serum for testing.

Anticoagulants

• Anticoagulatns prevent blood from fully clotting.
• Anticoagulatns are required for any whole blood or plasma sample.
• Two methods of preventing clotting are precipitating the calcium, or inhibiting the formation of thrombin.
• Types of Anticoagulants are Ethylenediaminetetraacetic acid (EDTA), Citrates, Oxalates, and Heparin

Ethylenediaminetetraacetic acid and Citrates

• EDTA comes in 2 forms; K2 and K3 forms which binds with Calcium.
• Lavender or purple tubes are most common. Pink, tan, royal blue, and white specialty tubes can also be found.
• EDTA is used for hematology and blood banking tests because they preserve cell morphology.
• Citrates bind with calcium and preserves clotting factors.
• Light blue tubes are used to test coagulation

Oxalates Heparin and Antiglycolytic Tubes

• Oxalates binds with calcium and are most commonly found in gray-top tubes.
• Heparin inhibits thrombin
• Heparin is used for tests that require faster Turn Around Time (TAT) and are for blood chemistry
• Green top tubes are most common, as well as green and grey, grey, black and royal blue.
• Because the cells are free flowing and not clotted, a blood specimen can separate through settling or centrifugation, and can be resuspended again

Mixing Anticoagulant Specimens

• Anticoagulant Specimens must be mixed immediately for accurate results.
• Gentle mixing prevents hemolysis, do not shake!
• Usually 3-10 inversions depending on if mixing specimens, consult the manufacturer instructions
  • SS = one inversion

Light Blue Top Tubes. and Special Use Anticoagulants

• Light blue–top tubes are used for coagulation testing.
• Contain a 9:1 ratio of blood to sodium-citrate additive.
• Vacuette® tubes have arrows to show a proper minimum and maximium, and to show the correct blood fill volume.
• Special-use anticoagulants include: -Acid citrate dextrose (ACD): used for blood banks, paternity tests, and transplants. Has two versions, A and B. -Citrate phosphate dextrose (CPD): used for blood banks. -Sodium polyanethol sulfonate (SPS): used for microbiology and blood cultures.

Antiglycolytic Agents

• Glycolysis is the breakdown of glucose by blood cells.
• Antiglycolytic agents include Sodium fluoride, as it preserves glucose for to up 3 days and inhibits bacterial growth.
• Potassium oxalate is also used for the test, as an anticoagulant for a rapid response

Clot Activators

• Clot activators enhance coagulation in serum-separator tubes (SST).
• Substances that provide more surface area for platelet activation, which can include any glass (silica) particles or any inert clays (Celite).
• Clotting factors can also include Thrombin.
• Blood in an SST tube should eventually clot even without any gentle mixing.

Serum or Plasma Separator Tubes and Order of Draw

• Serum or Plasma Separator Tubes have a thixotropic gel separator that has an equal density to the cell/or plasma.
• Gel moves between cells and serum or plasma.
• Prevents cells from continuing to metabolize substances during separation.
• Trace element-free tubes are made of materials free of trace element contamination and used for trace element tests, toxicology studies, and nutrient determinations. These tubes feature royal-blue stoppers.
• Always check the label for the additive
• Tubes that feature Non-separated gels use a flexible elastomer rather than a gel, and they can also conduct blood samples.

CLSI Order of Draw

• The CLSI (Clinical and Laboratory Standards Institute) has set a standard order of completing a multi-tube blood draw 1. Blood culture tube or bottles 2. Sodium citrate tube 3. Serum tube with or without gel 4. Heparin tube with or without gel 5. EDTA tube with or without gel separator 6. Sodium fluoride/potassium oxalate glycolic inhibitor
• This list indicates general stopper colors to help memorize the list like "Stop, Light, Red, Stay Put, Green, Lets Go"

Contamination

• Carryover/Cross-Contamination is where the transfer of an additive from one tube to the next. The additive touches the needle during the ETS collection.
• Blood is then transferred from a needle to the ETS tubes.
• Minimizing carryover happens when specimen tubes fill from the bottom, to prevent contamination and erroneous carryovers.
• Tissue Thromboplastin is an activator present in tissue fluid which activates extrinsic coagulation pathway. For coagulation, collect a few millimeters of blood into another tube before collecting the primary specimen.
• Microbial Contamination occurs when microorganisms are already on a patient's skin which can contaminate the blood specimens.
• For blood cultures, the sample is to be collected first for optimal site sterility to prevent any needle contamination.

Venipuncture Steps

• Obtain the request from the physician.
• Obtain the patient's consent and explain the necessary steps needed for the process.
• Sanitize your hands and put on the necessary equipment (gloves).
• In order to find a vein, position, apply the tourniquet on the patient, and instruct them to make a fist.
• Select the vein and release the tourniquet, and ask patient to stop making a fist.
• Follow the correct order when using the equipment.
• Reapply the tourniquet, uncap, and inspect the needle.
• Ask patient to remake a fist, anchor the vein, and insert the needle.