Anemia Flashcards
Hemostasis
Prevents prolonged hemorrhage spontaneous thrombosis
Pro thrombotic factors
Platelet activators, procoagulants, vasoconstrictors, fibrinolytic inhibitors
Anti thrombotic factors
Platelet inhibitors, anticoagulants, vasodilators, fibrinolytic activators
Steps of homeostasis
Vasoconstriction, platelet response, coagulation phase, fibrinolysis
Vasoconstriction step
Immediate restriction of blood flow; sympathetic and local factors like thromboxane and endothelin
Platelet response step
Forms initial plug within seconds; platelets stick to exposed collagen and each other, then release thromboxane and ADP to promote vasoconstriction, get more platelets, and start coagulation
Coagulation phase
Activation of serine proteases through extrinsic or intrinsic pathways to cause production of fibrin and form the clot proper
Fibrinolysis
Dissolution of the clot for wound healing and restoring blood flow
Plasmin
Active form of plasminogen that incorporates into clots and degrades fibrin polymers
TPA
Enzyme that activates plasmin
Plasminogen activator inhibitor 1 or 2 and alpha 2 antiplasmin
Bind and inhibit TPA or plasmin
Causes of excessive bleeding
Thrombocytopenia, von willebrand’s, hemophilia, vitamin k deficiency, fibrinolytic hyperactivity
Treatments for hemorrhage
Vitamin k, anti-fibrinolytic agents, replacement factors from blood
Forms of vitamin K
Phytonadione (k1), menaquinone (k2)
Mechanism of action of vitamin K
Confers activity to factors II, VII, IX, X
Vitamin k epoxide reductase
Reduces vitamin k so it is active again
Routes of admin for vitamin K
Iv (slowly), subcutaneous (preferred), has to be given with bile salts for intestinal absorption
Side effects of vitamin k
Generally very safe
Uses for vitamin k
Anticoagulant toxicity, vitamin k deficiency, preventing hemorrhage in newborns
Fibrinolytic inhibitors
Aminocaproic acid
Mechanism of fibrinolytic inhibitors
Competitively inhibit plasmin’s action on fibrin
Effect of too much aminocaproic acid
Thrombosis
Uses for aminocaproic acid
Bleeding from fibrinolytic therapy, hemophilia
Plasma fractions
Use for deficiencies in plasma factors
Hemophilia A
Factor VIII deficiency
Hemophilia B
Factor IX deficiency
Desmopressin acetate
Increases factor VIII in hemophilia or VW; have tablets, injectable, or nasal spray
Protamine sulfate
Cationic protein that neutralizes heparin (more effective against high MW); have to give slowly
Aim of anemic therapy
Form RBCs and hemoglobin
Nutrients for anemia
Iron, folic acid, vitamin B12
Iron for anemia
Oral as ferrous salts, injected as colloidal suspension of iron
Erythropoietin
Recombinant version used in chronic anemia, increases hematocrit and hemoglobin in 2-6 weeks; should take with iron
Adverse effects of EPO
Hypertension and thrombosis
Route of admin of EPO
Injection
Filgastrim
rHuG-CSF to stimulate neutrophils, important during transplants after chemo and with neutropenia
Oprelvekin
IL-11 to stimulate all cell lineages; used for thrombocytopenia
