Phlebotomy Book Notes Ch. 7 Blood Collection Equipment, Additives, and Order of Draw
General Blood Collection Equipment and Supplies
Tourniquets: Used to restrict blood flow and make veins more visible during venipuncture.
Needles: Various gauges available; typically 21 to 23 gauge for venipuncture.
Blood Collection Tubes: Color-coded to indicate the type of additives inside.
Alcohol Swabs: Used for disinfecting the site before puncture.
Labels: Necessary for the proper identification of patient samples.
Bandages: Applied after collection to prevent bleeding.
Blood-Drawing Station: A designated area equipped with all necessary supplies for performing blood draws safely and efficiently, ensuring a sterile environment.
Essential for conducting blood draws. Includes:
Table for supplies.
Phlebotomy Chairs: Ergonomically designed seats that provide comfort for patients during the blood draw process, allowing for easy access to the arms while minimizing patient anxiety.
Handheld Phlebotomy Equipment Carriers: Portable containers designed for safe transport and organization of phlebotomy supplies, ensuring that all necessary instruments and materials are readily available at the site of blood collection.
Phlebotomy Carts: Mobile units equipped with storage compartments for various blood-collection supplies, such as tubes, needles, and antiseptics, enhancing efficiency by keeping all tools within reach during the procedure.
Maintaining stocked carts and trays is a critical responsibility for phlebotomists.
Gloves and Glove Liners: Essential personal protective equipment that provides a barrier to protect both the phlebotomist and the patient from potential contamination and infection during blood collection procedures.
Mandatory usage as per CDC/HICPAC and OSHA guidelines.
New gloves are required for each patient.
Types of Gloves:
Nonsterile gloves: These are typically used for routine venipunctures and other procedures where there is a low risk of exposure to blood or infectious materials.
Sterile gloves: Essential for collecting blood samples in a sterile environment or for procedures involving open wounds to prevent contamination.
Exam gloves: These provide a barrier against blood and other bodily fluids while allowing for sufficient dexterity during procedures.
Vinyl gloves: A suitable alternative for individuals with latex allergies, offering protection against blood and bodily fluids, though typically less durable than nitrile gloves.
Nitrile gloves: Highly resilient and puncture-resistant, these gloves are ideal for blood collection as they provide excellent protection against chemicals and infectious materials.
Latex gloves: Although less commonly used due to allergies, they offer good stretchability and tactile sensitivity, making them an option for those without latex sensitivities.
Glove Liners: Can be used if allergies occur; powdered gloves are not recommended.
Antiseptics: Used to disinfect the skin before blood collection, commonly used antiseptics include alcohol swabs and iodine solutions, which help to reduce the risk of infection at the puncture site.
Most Common Antiseptic: 70% isopropyl alcohol, safe for skin.
Disinfectants: These are used to clean surfaces and equipment to prevent contamination, and common examples include bleach solutions and sodium hypochlorite.
Unsafe for human skin.
Hand Sanitizers: Alcohol-based options can substitute handwashing when hands are not visibly soiled.
Gauze Pads: Gauze pads are used to cover the puncture site after blood collection, helping to control bleeding and protect the area from infection.
Use clean 2 × 2-inch gauze pads to apply pressure post-collection.
Some pads include fluid-proof backing to avoid contamination.
Avoid cotton balls due to sticking issues.
Bandages: These should be latex-free and hypoallergenic to minimize any risk of allergic reactions.
Applied once bleeding ceases; can use paper, cloth, or knitted tape over gauze.
Patient Identification Equipment: It is crucial to confirm patient identity using at least two unique identifiers, such as full name and date of birth, before proceeding with blood collection. Utilizing wristbands or labels that include this information can help ensure accurate identification.
Needle and Sharps Disposal Containers: These containers must be puncture-resistant, leak-proof, and clearly labeled to ensure the safe disposal of used needles and other sharp instruments. It is essential to keep these containers in accessible locations to encourage proper disposal practices and reduce the risk of needle-stick injuries.
Venipuncture Equipment:
This includes various types of needles, syringes, and blood collection tubes specifically designed for venipuncture procedures. Among these, multi-sample needles with safety features are preferred for their ability to draw multiple tubes with a single puncture, thereby minimizing patient discomfort.
Vein-Locating Devices: These devices assist phlebotomists in accurately locating veins for blood draws, particularly in patients with challenging venous access. This may include portable ultrasound machines or infrared vein finders, which enhance visibility and increase the likelihood of a successful first-attempt puncture.
Tourniquet: This essential tool temporarily restricts blood flow, engorging the veins and making them easier to palpate and puncture. Tourniquets can be made from elastic material or a simple strap and should be applied above the venipuncture site for optimal results.
Needles: Various types of needles are used in phlebotomy, including straight needles, butterfly needles, and safety needles, each designed for specific tasks and patient needs.
Characteristics: Sterile, disposable, single-use design.
Types:
Multisample:
Hypodermic:
Winged infusion (butterfly)
Parts of Needle:
Bevel: The angled tip of the needle designed to facilitate entry into the skin and minimize tissue trauma.
Shaft: The long, straight part of the needle that connects the bevel to the hub, responsible for guiding the flow of blood from the collection site to the tube.
Hub: The part of the needle that connects it to the syringe or blood collection tube, ensuring a secure fit and preventing leakage during the blood draw.
Lumen: The hollow interior of the needle shaft through which blood flows, playing a crucial role in the efficiency and speed of the blood collection process.
Needle Gauge: The needle gauge indicates the needle diameter; a higher gauge number corresponds to a smaller needle, which affects blood flow and patient comfort.
Common phlebotomy gauges: 25, 23, 22, and 21.
Length: 1- and 1.5-inch needles are most typical for venipuncture.
Safety Features: Some tube holders or needles include safety features.
Evacuated Tube System (ETS): A method widely used for blood collection, which allows for quicker and safer sample collection by utilizing vacuum-sealed tubes that automatically draw the required volume of blood.
Allows multiple tubes to be collected during a single venipuncture.
Components:
Multisample Needles:
Designed for collecting multiple tubes during one venipuncture.
Feature: Double-pointed ends with a threaded part for holder attachment; includes a retractable sleeve to prevent leakage.
Options available with or without safety features.
Common types of multisample needles are typically 21 to 23 gauge, which balance patient comfort with adequate blood flow for various tests.
Needle and Holder Units:
Units with needles permanently attached to holders.
Evacuated Tubes:
Available in various sizes and types.
Used with both ETS and syringe methods, dictated by the patient’s age and vein condition.
Must be disposed of as a unit post-use, per OSHA guidelines.
Evacuated Tubes Characteristics:
Generally made of glass or plastic, designed to create a vacuum for drawing blood.
Color-coded tops indicate the presence of specific additives for different tests.
Available in various sizes, such as 2 mL, 4 mL, and 10 mL, to accommodate different sample volumes.
Vacuum: Negative pressure that draws blood into the tube.
Additive Tubes: Tubes with substances such as anticoagulants or clot activators; color-coded for identification.
Expiration Dates: Indicated on tube labels for both additives and vacuum efficacy.
Syringe System: A common method for blood collection that utilizes a syringe and a needle, allowing for manual control over the blood draw process.
An alternative system for patients with small or difficult veins.
Components include:
Syringe Needles: 1- to 1.5-inch long, must include resheathing features.
Syringes: Composed of barrels and plungers.
Syringe transfer devices: Allow safe blood transfer to tubes without using the syringe needle.
Blood Collection Sets: These are preassembled kits that typically include a needle, a holder, and tubing, designed to facilitate blood collection from veins.
Winged infusion sets (butterflies) are used for small or difficult veins.
Can connect to both tube holders and syringes.
Nonwinged blood collection sets like VANISHPOINT feature automated in-vein retraction to minimize exposure risk.
Combination Systems:
Integrative systems for blood collection, enabling collection via tube or syringe.
Contains safety devices and varies in needle designs.
Blood Collection Additives
Anticoagulants:
Prevent blood clotting through:
Precipitating calcium
Inhibiting thrombin formation.
Types Include:
Ethylenediaminetetraacetic acid (EDTA): An anticoagulant that binds calcium ions, preventing blood coagulation and preserving cellular components for hemoglobin and hematology tests.
Citrates: Anticoagulants that also bind calcium, often used for blood donation and certain laboratory tests, they help maintain the integrity of plasma during analysis.
Oxalates: Anticoagulants that inhibit coagulation by forcing calcium to bind, these additives are commonly used in glucose tests and for preserving blood samples for further analysis.
Heparin: A fast-acting anticoagulant that inhibits thrombin and factor Xa, it is primarily used for hemostasis tests and therapeutic applications in clinical settings.
Mechanism: Allows cell separation through settling or centrifugation without clotting.
Specimen Mixing:
Anticoagulant specimens must be mixed gently immediately to prevent hemolysis; consult the manufacturer for the inversion number.
Fill Levels for Light Blue-top Tubes:
Must maintain a 9:1 blood-to-additive ratio, requiring at least 90% fill for accurate results.
Special-Use Anticoagulants:
ACD: (Acid Citrate Dextrose) is used primarily for blood bank procedures and some specialized tests, providing effective anticoagulation.
CPD: (Citrate Phosphate Dextrose) is commonly used for blood preservation, especially in transfusion medicine, and helps maintain the viability of red blood cells.
Sodium polyanethol sulfonate (SPS): an anticoagulant that is primarily used in blood cultures to prevent the clotting of blood samples, thus allowing for accurate microbial growth.
Antiglycolytic Agents:
Prevent the breakdown of glucose in blood; primarily sodium fluoride for preserving glucose for up to 3 days.
Clot Activators:
substances that promote coagulation, such as glass particles or inert clays, in serum-separator tubes (SSTs).
Serum or Plasma Separator Tubes: These tubes contain a gel that separates serum or plasma from blood cells after centrifugation, allowing the collection of clear samples free of cellular material.
Utilizes a thixotropic gel separator to prevent cell metabolism during centrifugation; specifically designed with royal-blue stoppers for trace element tests.
Order of Draw
CLSI Order of Draw Sequence:
Blood culture tubes or bottles (sterile) for microbiology tests to detect infections, such as bacterial or fungal growth, are collected before other tubes to avoid contamination.
Sodium citrate tubes (light blue stopper) for coagulation tests, such as PT and aPTT, which prevent blood from clotting by binding calcium.
Serum tubes (with or without gel) (red or gold stopper) for tests requiring serum, as they allow blood to clot and facilitate separation of serum from cells after centrifugation.
Heparin tubes (with or without gel) (green stopper) are used for numerous tests that require plasma, as they inhibit thrombin and prevent clot formation.
EDTA tubes (with or without gel separator) (purple or lavender stopper) are employed for hematology tests and ensure that blood samples do not clot by chelating calcium, making them essential for complete blood counts (CBC) and blood smears.
Glycolic inhibitors tubes (Sodium fluoride/potassium oxalate) (gray stopper) are utilized for glucose testing and lactic acid measurements, as they preserve the integrity of the sample by preventing glycolysis.
Memory Jogger:
Be Careful or Stop - Blood culture or SPS (yellow),
Light - Citrate tube (light blue),
Red - Serum tubes (red),
Stay - SST, Put - PST,
Green - Heparin tubes (green),
LEts - EDTA tubes (purple),
Go - Glycolic inhibitor tubes (gray)
Implications of Order of Draw
Carryover/Cross-Contamination Risks:
Additives can transfer between tubes due to improper collection methods (e.g., blood touching the needle during ETS collection).
Order of draw minimizes risks.
Tissue Thromboplastin Contamination:
Present in tissue fluid; activates coagulation pathways, potentially conflicting with coagulation tests.
In coagulation tests (excluding PT or PTT), draw a preliminary tube before collecting the specimen.
Microbial Contamination in Blood Cultures:
Blood cultures should always be collected first to ensure the sterility of the site and avoid contamination.