ANTICOAGULANTS by - KamakshiWhole blood:- A venous, arterial or capillary blood sample in which the concentrations and properties of cellular and_ extra-cellular constituents remain relatively unaltered when compared with their in- vivo state. Anticoagulation in-vitro stabilizes the constituents in a whole blood sample for a certain period of time. Plasma:- The virtually cell-free supernatant of blood containing anticoagulant obtained after centrifugation. Serum: The undiluted, extracellular portion of blood after adequate coagulation is complete. Anticoagulants:- Additives that inhibit blood and/or plasma from clotting ensuring that the constituent to be measured is non- significantly changed prior to the analytical process. Anticoagulation occurs by binding calcium ions (EDTA, citrate) or by inhibiting thrombin activity (heparinates, hirudin).1) Toprepare the whole blood or the plasma, anticoagulants are needed. 2) Blood is a combination of formed elements (RBCs, WBCs, Platelets) in a liquid portion called plasma. 3) These are used to prepare the whole blood or plasma during the collection of blood samples. 4) There is a difference in the plasma and the serum for estimating various substances in the blood. labpedia Serum and plasma formation. EDTA (Ethylenediaminetetraacetic acid):- + This is useful for the hematological examination. + EDTA is used as a disodium or dipotassium salt. ° Mechanism of action: 1. This is a chelating agent that binds the calcium, which is needed for coagulation. Chelation prevents coagulation Chelating agent (ee {EprAy— ew eee ED) Prev; clot formation (Coagulation) Increased EDTA concentration Cause shrinkage of RBCs © nnivits Atkatine phosphatase © Nor suitable for Ca++ and Fe++ estimation Qe A. 1 to 2 mg/mL. of blood used as: B. 0.1% solution and evaporate pn the test tube labpedia net Mechanism of EDTA as an anticoagulant 4s.— —— ‘A preserves the morphology of the blood cell structure. © This is the anticoagulant of choice for hematocrit, Hb, and differe: cou © This is the best anticoagulant for peripheral blood smears and studies. © There is less increase in the cell volume after keeping the blood. Drawbacks: * It inhibits alkaline phosphatase, creatine kinase, and leucine aminopeptidase activities. * EDTA is not suitable for Calcium and iron estimation. . Heparin This is used in the DVT (deep vein thrombosis) It is used in pulmonary embolism. This is used as a prophylactic drug in venous thrombosis. Properties of Heparin: * This is an anticoagulant and causes the least interference with the test. © This is theoretically the best anticoagulant because it is a normal blood component and does not introduce any foreign contaminants to the blood specimen. ee enechanism of action: ——— Activates | Heparin, ————> Antithrombin III Inactivate Prothrombin Thrombin Inhibits acid phosphatase Fibrinogen ne bris fatipedianet No fibrin clot formation Heparin function as an anticoagulanttact does not al arin accelerates antithrombin ‘action, which _neutrajiz4s thrombin, thus preventing the formation of fibrin from fibrinogen. » It forms the complex of thrombin + antithrombin cofactor + heparin and prevents fibrin clot formation. » It prevents the coagulation for 24 hours by neutralizing the thrombin, thus preventing fibrin clots’ formation from the fibrinogen. Solution preparation of the heparin: © Heparin is added 0.2 mg / mL of blood in each test tube © Ora drop of heparin is drawn into the syringe « Advantage: + This is the best anticoagulant to use dry when minimal hemolysis is desired, e.g., sodium and potassium estimation. + This is the best anticoagulant used to estimate pH, blood gases, electrolytes, and ionized calcium. Drawback + Itis costly. + Itinhibits the acid phosphatase activity. It gives a blue background for Wright's stain smears, so not good for peripheral blood smear interpretation. of. + It also affects the bindis ‘iiodothyronine and thyroxine to their carrier protein and produces a higher free concentration of these hormones. + Itis not used for coagulation and hematology studies. + Ammonium heparin affects the RBCs volume. 7Mechanism: This may be sodium, potassium, ammonium, or lithium oxalic acid salt used as an anticoagulant. Cat + | K2C204.120 > Insoluble complex Pr ona Chelate | Precipitate as Ca alt labpedia.net Inhibit coagulation Potassium oxalate mechanism as an anticoagulant| indications: © Sodium citrate is widely used for coagulation studies. © For PT and PTT. Mechanism of action: Insoluble complex Chelate | Trisodium citrate Binding Ca** in Inhibit coagulation nonionized form labpedianet Mechanism of Sodium citrate as an anticoagulantin preparation and-uses: = © Trisodium citrate= 3.2 to 3.8 g/dL (3.2% solution). © Mix well Trisodium citrate 3.8 grams in distle water. © In blood, its ratio is 1:9, where 9 parts are blood, and 1 part is sodium citrate. Drawbacks:- © This is used in liquid form (liquid anticoagulant). © This is not a good anticoagulant for a complete blood examination. ® This is not good for the estimation of calcium. © It inhibits aminotransferase and alkaline phosphatase.ssium Oxalate———___ Mechanism: This may be sodium, potassium, ammonium, or lithium oxalic acid salt used as an anticoagulant. neo of complex os late Chelate oxal veda as Ca* salt labpedia net Inhibit coagulation Potassium oxalate mechanism as an anticoagulantition: ee © Potassium oxalate at a concentration of 1 to 2 mg/mL of blood is us * The combination of ammonium/potassium oxalate does not lead to shrinkage of the RBCs. * While other oxalates cause shrinkage. Drawbacks: © Ifthe concentration is >3 mg/mL, then there are chances for hemolysis. © There is a reduction of 10% hematocrit. * Oxalates inhibit several enzymes like acid phosphatase, alkaline phosphatase, amylase, LDH. © It may cause precipitation of calcium as oxalate salt.This is a weak anticoagulant but used an antiglycolytic ager preserve the glucose. ii. This inhibits the system involved in glycolysis and preserves the glucose. Mechanism of action:-It acts in two ways a) Asan anticoagulant by binding the calcium. b) Asan enzyme inhibitor which prevents the glycolytic enzyme from destroying the glucose. Glycolysis Breakdown — a Lactic acid Enzyme inhibitor ——— Sodium fluoride labpedia net Sodium fluoride role in stopping the glycolysis 5As an anticoagulant ——® Prevents ——* Binds C» clotting As an enzyme inhibitor ——+ Prevents glycolysis Weak anticoagulant | sap Glucose level will not fal Sodium fluoride as an anticoagulant Solution: ‘This is effective at a concentration of 2 mg/mL of blood along with another anticoagulant like potassium oxalate. *Sodium fluoride is poorly soluble, so mix blood thoroughly before effective anti- glycolysis occurs. +This is mostly used for glucose estimation. Drawback *This is also an inhibitor of many enzymes. *Also, effect urease for the estimation of urea. 4Toable showing the difference between the contents of plasma and serum Plasma contents Contains all proteins (albumin, globulins, and fibrinogen) Contains fibrinogen 90% of water (92 to 95%) RBCs, WBCs, and platelets are suspended in plasma Electrolytes same level Antibodies are present Gases (CO2, 02, and N2) Glucose, amino acids, cholesterol, and fats Excretory products like urea, uric acid, creatinine, and bile products The same value of bilirubin, cholesterol, and creatinine Serum contents Fluid remaining after coagulation No fibrinogen 90% of water No RBCs, No WBCs, No platelets Electrolytes same level No prothrombin Antibodies are present No clotting Factor VIN, V, XIIT Contain factor XI, XI. X, IX. VIE Contain rest of all products like plasma Excretory products present The same value of bilirubin, cholesterol, and creatinineet Ny The difference hetween plasma and serum: Characteristics Plasma Serum Fibrinogen 0.2 to. 0.4 G/dL Nil Formation site Present in the body fluid Prepared outside the body Outside, the body Always contains anticoagulant Never anticoagulant added containsShank you