HEMOSTASIS

• Clotting factors: 1 - 13
• Clotting factors 1 – 13
• No clotting factors 3, 4, 6
• IP and EP both converge in clotting factor 10
• Plasmin – enzyme that cleaves fibrin and dissolves the clot
• Most clotting factors are produced in the liver and their production requires vitamin K
• HEMOSTASIS Process that controls bleeding at the site of injury.
• Blood loss is stopped by the formation of bloodclots that seal the breaks in blood vessels.
• Transient Vasoconstriction

  → Prostaglandin (thromboxane A2)

  → Serotonin

  → Noradrenaline

  → Endothelial cells
• Hemostatic/ Platelet plug

  → Primary Hemostasis

  → Platelets get stuck to exposed collagens through

  von Willebrand Factor (vWF)
• Fibrin clots

  → Secondary Hemostasis

  → Thrombin converts fibrinogen to fibrin
• THROMBOSIS – most common cause of blocked arteries in heart attacks (MI), strokes (CVA) and pulmonary embolism
• RED CELL COUNT

  Number (in millions) of erythrocytes/uL of blood
• RED CELL COUNT

  Altered erythropoiesis, anemias, hemorrhage, hodgkin disease, leukemia
• HEMATOCRIT DETERMINATION

  Percentage of a given volume of blood that is occupied by erythrocytes
• HEMOGLOBIN DETERMINATION

  Amount of Hgb (by weight)/dl of blood
• MEAN CORPUSCULAR HEMOGLOBIN CONCENTRATION (MCHC)

  Concentration of Hgb in each erythrocyte (% of erythrocyte occupied by Hgb)
• MEAN CORPUSCLE HEMOGLOBIN (MCH)

  Amount of Hgb in erythrocyte (by weight)
• MEAN CORPUSCLE VOLUME (MVC)

  Size of erythrocytes
• RETICULOCYTE COUNT

  Number of reticulocytes/uL of blood (also expressed as % of reticulocytes in total RBC count)
• SERUM FERRITIN DETERMINATION

  Depletion of body iron (potential deficiency of heme synthesis)
• TOTAL IRON – BINDING CAPACITY (TIBC)

  Amount of iron in serum plus amount of transferrin available in serum
• TRANFERRIN SATURATION

  % of transferrin that is saturated with iron
• PORPHYRIN ANALYSIS (PROTOPORPHORIN ANALYSIS)

  Concentration of protoporphyrin in erythrocytes (mcg/dl), an indicator of iron – deficient erythropoiesis
• DIRECT ANTIGLOBULIN TEST (DAT)

  Antibody binding to erythrocytes
• ANTIBODY SCREEN TEST (INDIRECT COOMBS TEST)

  Detections of antibodies to erythrocytes antigens (other than ABO antigens)
• PLATELET COUNT

  Number of circulating platelets (in thousands)/uL of blood
• BLEEDING TIME

  duration of bleeding following a standardized superficial puncture wound of skin, integrity of platelet plug, measured in minutes following puncture
• CLOT RETRACTION TEST

  platelet number and function, fibrinogen quantity and use, measured in hours required for expression of serum from a clot incubated in a test tube
• PLATELET ADHESION STUDIES

  ability of platelets to adhere to foreign surfaces
• PLATELET AGGREGATION TESTS

  ability of platelets to adhere to one another
• WHOLE BLOOD CLOTTING TIME (LEE – WHITE COAGULATION TIME)

  overall ability of blood to clot, as measured in minutes in a test tube
• CIRCULATING ANTICOAGULANT (IgG) ANTIBODIES THAT INHIBIT COAGUALATION

  presence of antibodies that neutralize clotting factors and inhibit coagulation, as indicated by prolonged clotting time, prothrombin time or partial thromboplastin time
• PARTIAL THROMBOPLASTIN TIME (PTT)

  effectiveness of clotting factors (except factor VII and VIII), effectiveness of intrinsic pathway of coagulation cascade, as measured by a test tube in seconds
• PROTHROMBIN TIME

  effectiveness of activity of prothrombin. fibrinogen, and factors V. VII and X: effectiveness of vitamin K dependent coagulation factors or extrinsic and common pathways of coagulation cascade as measured in a test tube in seconds
• THROMBIN TIME

  quantity and activity of fibrinogen as measured in a test tube in seconds
• FRIBRINOGEN ASSAY

  amount of fibrinogen available for fibrin formation
• FIBRIN – FIBRINOGEN DEGEADATION PRODUCTS

  fibrinogen activity as measured by levels of fibrin-fibrinogen degradation products
• PORPHYRIN ANALYSIS (PROTOPORPHORIN ANALYSIS)

  Concentration of protoporphyrin in erythrocytes (mcg/dl), an indicator of iron – deficient erythropoiesis
• ANTIBODY SCREEN TEST (INDIRECT COOMBS TEST)

  Detections of antibodies to erythrocytes antigens (other than ABO antigens)