Post on 21-Dec-2015
Coagulation CascadeHow a clot forms in the body
3 PathwaysIntrinsic Pathway (Factor 12,11 and 9)Extrinsic Pathway (Factor 7 and 10)Common Pathway (Factor 2 and 13)
Factor = protein
Protease = proteolytic enzyme that breakdowns protein into smaller polypeptides or amino acids *activates factor
Intrinsic Pathway
• coagulation proteins (Factors) circulate in inactive form in the blood• Endothelium is devoid of thrombogenic tissue factor and collagen• Brisk blood flow removes any activated proteins
Factor 12 (inactive) 12a
Factor 11 (inactive) 11a
Factor 9 (inactive) 9a
Factor 8 (von Wiilebrand Factor) activates to 8a
Factor 9a and 8a will activate Factor 10 which is the first factor in Common Pathway
Extrinsic Pathway
Trauma needs to occur to the blood vessel to activate tissue factortissue factor
Factor 7 7a
Factor 1010a
Common Pathway10a
activated by 9a and 8a (intrinsic) or 7a and tissues factor (extrinsic)
Factor 2 2a prothrombin thrombin
2a converts fibrinogen to fibrin (monomer)
Factor 13 13a(causes monomers to mesh)
Fibrin Clot
Cascade
Factor 12 12a
Factor 11 11a
Factor 9 9a
Factor 8 (von Wiilebrand Factor) activates to 8a
tissue factorFactor 7 7a
Factor 10 10a
10a
Factor 2 2a prothrombin thrombin
2a converts fibrinogen to fibrin (monomer)
Factor 13 13a (causes monomers to mesh)
Fibrin Clot
Fibrinolytic
Breakdown fibrin clot by converting plasminogen to plasmin
“clot buster” tPAUrokinaseStreptokinase
Anticoagulation
Prevents fibrin clot from forming by inhibiting activation of Factors within the Coagulation Cascade
Coumarins
HeparinDirect Factor 10 InhibitorsDirect Factor 2 Inhibitors
Common Uses for Anticoagulation in Acute Care
Prevention of blood clot /pulmonary embolism formationAtrial Fibrillation (valvular and non-valvular)Post Orthopedic Surgery (THR, TKR)
Treatment of blood clot/pulmonary embolism
Stroke
Coumadin (Warfarin)
Inhibits Vitamin K in synthesis of factors in Cascade Inhibits Factors 10, 9, 7 and 2 Therapeutic INR 2.0-3.0 Blood draws Bridging with Lovenox
Inhibitors Direct Factor 2 inhibitor
Pradaxa (Dabigatran)
Direct Factor 10 inhibitor Arixtra (Fondaparinux)
Xarelto (Rivaroxaben)
Eliquis (Apixaban)
Lovenox (Enoxaparin) LMWH
Testing
PT and PTT - Test together to figure out bleeding or clotting disorder
Prothrombin Time (Factor 1, 2, 5, 7, 9, 10, 11)Intrinsic Pathway
Partial Thromboplasmin Time (Factor 1, 2, 5, 7, 10)Extrinsic Pathway
INR
International Normalised Ratio how long it takes the blood to clot
INR = (prothrombintest / prothrombincontrol)isi
The ISI is a numerical value representing the responsiveness of any given commercial system relative to the international standard.
Physical Therapy Intervention
PrecautionsEarly Identification of a medical emergency
HIT Heparin Induced ThrombocytopeniaType 2
Life threatening
may manifest as skin lesions at heparin injection sites
acute systemic reactions (chills, fever, dyspnea, chest pain)
Precautions Continued
Dosing and therapeutic levels Bleeding – main side effect of anticoagulants Ability to reverse anticoagulation effects