Anticoagulation in the

Acute Care Population

Aimee Ring PT, DPT, GCS

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

Benefits of Mobility

Early mobilization and prevention of blood clots

Mobilization with the presence of blood clot and pulmonary embolism