BLOOD COLLECTION EQUIPMENT, ADDITIVES AND ORDER-OF-DRAW Blood Is a specialized body fluid that delivers necessary substances to body’s cells 5 – 6 liters or 7 – 8% of the TBW (in an adult) Composition: 45% is composed of formed elements, red blood cells (RBC), white blood cells (WBC), and platelets (plt) 55% is the fluid portion o 90% is water and 10% composed of CHON, CHO, vitamins, hormones, enzymes, lipids, and salts o Plasma Liquid portion of blood when coagulation is prevented by the use of an anticoagulant o Serum Liquid portion of blood released from the clot VENIPUNCTURE The process of collecting or “drawing” blood from a vein Equipment 1. Antiseptics Are substances used to prevent sepsis, the presence of microorganisms or their toxic products in the bloodstream Antiseptics used in blood collection o 70% ethyl alcohol o 70% isopropyl alcohol o Benzalkonium chloride (Zephiran chloride) o Chlorhexidine gluconate o Hydrogen peroxide o Providone-iodine (0.1 – 1%) o Tincture of iodine 2. Sterile gauze pads Are used to hold pressure over the site following blood collection procedures 3. Tourniquet Is a device applied or tied around a patient’s arm prior to venipuncture Vein-locating devices o Transillumination devices such as Venoscope II o Vein Entry Indicator Device (VEID) 4. Needles Multisampling needles Hypodermic needles Winged infusion (butterfly) needles Are designated by gauge number o Needle gauges w/ needle type & their use Gauge Needle type Use 15 – 17 attached to collection bag collection of donor units 18 syringe transfer needle Gauge 20 21 Needle type multisample syringe multisample syringe 22 multisample syringe 23 butterfly Length of the needle o Multisample & syringe come in 1-inch to 1.5-inch o Butterfly have ½ to ¾ inch Use w/ normal sized veins standard venipuncture needle px w/ difficult veins pediatric veins 5. Evacuated Tube System (ETS) A closed system in which the patient’s blood flows through a needle inserted into a vein, directly into a collection tube 3 basic components: o A special blood-drawing needle o A needle and a tube holder o Various types of evacuated tube 6. Syringe System Used for patients with small or difficult veins 7. Bandages Used to cover a blood collection site after the bleeding has stopped 8. Anticoagulants Are substances that prevent blood from clotting by either two (2) methods: o Removal of Calcium Chelation Precipitation o Inhibiting the formation of thrombin EDTA (Ethylenediamine tetra-acetic acid) o Prevents coagulation by chelating calcium o 3 forms Versene (dry or powder form) Na2EDTA Sequestrene (liquid and spray dried form) K2EDTA spray dried form K3EDTA liquid form o Optimal concentration is 1.5 mg/mL of blood o Advantages: Preserves cellular morphology Prevents platelet clumping and artifact formation o Disadvantages: Excessive EDTA causes cells to shrink Not satisfactory for coagulation studies o EDTA is contained in Lavender top tubes Microcontainers w/ lavender tops Pink plastic-top tubes Royal blue top tubes White top tubes Citrates (Sodium Citrate) o Prevents coagulation by chelating calcium o Used routinely for coagulation studies and for platelet aggregation studies o Also used to monitor heparin therapy o 2 concentrations 3.2% (0.109 M or 0.105 M) 3.8% (0.129 M) o The standard ratio of blood to citrate is critical for coagulation test results to be valid 9:1 ratio o Advantages: Helps stabilized pH Used in combination with dextrose (ACD or CPD) Heparin o Prevents coagulation by inhibiting the formation of thrombin o Used primarily for plasma chemistries and potassium determinations o Optimal concentration is 15 – 30 U/mL of blood o 3 formulations Ammonium heparin Lithium heparin Sodium heparin o Advantages: Prevents hemolysis Less toxic than sodium citrate o Disadvantages: Causes morphologic distortion of platelets and leukocytes Produces bluish discoloration in the background of blood films Oxalates (Potassium oxalate) o Prevents coagulation by precipitating calcium o Used for glucose testing and alcohol levels o Contains antiglycolytic agents such as sodium fluoride and lithium iodoacetate Table of Collection Tube Colors and Additives: Color Stopper Red (glass) Red (plastic) or Gold Lavender (glass) Lavender (plastic) White Royal blue Green (plastic) Pink Light blue Black Green Additive None Clot activator/gel separator K3EDTA K2EDTA EDTA & gel Na heparin & Na2EDTA K2EDTA K2EDTA 3.2% or 3.8% sodium citrate Buffered Na citrate Sodium heparin Lithium heparin Ammonium heparin Additive function None Silica clot activator Laboratory Use Chem, Sero, BB Chem & Sero Chelates calcium Chelates calcium Chelates calcium Inhibits thrombin & chelates calcium Chelates calcium Chelates calcium Chelates calcium Plasma, hema, CBC Plasma, hema, CBC Plasma, molecular dx Plasma, chem., toxicology Plasma, lead testing Blood banking Plasma, coagulation (PT, PTT, factor assays) Westergren ESR Plasma chem. Chelates calcium Inhibits thrombin formation Green (glass) ; Brown Sodium heparin Inhibits thrombin Plasma, lead testing Light green Lithium heparin & gel Gray Potassium oxalate w/ Na fluoride & lithium iodoacetate Thrombin Inhibits thrombin formation Inhibits glycolysis Plasma chem., potassium levels Plasma glucose testing, alcohol levels Clot activator STAT chem Orange Order of Draw The special sequence of tube collection 1. Sterile tube or blood culture tube (yellow) 2. Sodium citrate tube (light blue) 3. Serum tubes w/ or w/out clot activator or gel separator (red) 4. Heparin tube w/ or w/out gel plasma separator (green) 5. EDTA tube (lavender) 6. Glycolytic inhibitor tube (gray) Alternate Syringe order of filling evacuated tube 1. Sterile tube or blood culture tube (yellow) 2. Sodium citrate tube (light blue) 3. EDTA tube (lavender) 4. Heparin tube w/ or w/out gel plasma separator (green) 5. Glycolytic inhibitor tube (gray) 6. Serum tubes w/ or w/out clot activator or gel separator (red) Effect of Anticoagulants/Additives on Various Blood tests/analytes Additive EDTA Oxalate Citrate Heparin Test Alkaline phosphatase Creatine kinase Leucine aminopeptidase Calcium and iron PT and APTT Sodium and potassium Platelet aggregation Acid phosphatase Alkaline phosphatase Amylase LDH Calcium Sodium and potassium Cell morphology ALT, AST Alkaline phosphatase Acid phosphatase Amylase Calcium Sodium and potassium Labile coagulation factors Triiodothyronine Thyroxine PT and APTT Effect Inhibits Decrease Increase Prevents Inhibits Decrease Increase Distorts Inhibits Stimulates Decrease Increase Preserves Increase Fluorides Wright’s stain Lithium (LiHep tubes only) Sodium (NaHep tubes only) Acid phosphatase Alkaline phosphatase Amylase Creatine kinase ALT, AST Cell morphology Causes blue background Increase Decrease Distorts mtkennygcortes