Hypercoagulable States

Question 1

Venous thrombosis

Answer 1

Composed of fibrin and red cells

Arise in large venous sinuses in the calf or at sites of vessel damage

Occurs when the activation of blood coagulation exceeds the ability of natural anticoagulant mechanisms and the fibrinolytic system to prevent fibrin formation

Major hip or knee surgery- big predisposing factor and also thrombophilia( acquired or genetic defect)

Question 2

Genetic Hypercoagulable states

Answer 2

1. Factor V leiden mutation
2. Antithrombin III deficiency
3. Protein C deficiency
4. Protein S deficiency
5. Fibrinolysis defects (plasminogen, thrombomodulin deficiencies)
6. Factor VIIIa excess
7. Homocysteinemia

Question 3

Acquired Hypercoagulable states

Answer 3

• prolonged bed rest
• Myocardial infarction
• Tissue damage
• Cancer
• Prosthetic cardiac valves
• Antiphospholipid Antibody Syndrome
• Atrial fibrillation
• Cardiomyopathy
• Nephrotic syndrome
• Smoking
• Sickle cell anemia
• Orac contraceptive use

Question 4

Clinical features of DVT

Answer 4

Leg pain, tenderness and swelling

A palpable cord

Discoloration and Venous distension

Differential diagnosis includes; Cellulitis, Popliteal cyst, Lymphadenitis

Question 5

Clinical features of Pulmonary Embolism

Answer 5

Remember definition of emboli

Anxiety, Apprehension, and Confusion

Dyspnea and Tachypnea

Pleuritic chest pain

Cough and Haemoptysis

Cardiovascular collapse with hypotension, syncope and coma

Question 6

Investigations for Hypercoagulable states

Answer 6

aPTT
PT
FDP( fibrin degradation products)
Doppler uss
Venography
Pulmonary angiography
Spiral ct

Question 7

Treatments

Answer 7

No treatment in asymptomatic patients with protein C deficiency

Pts who’ve experienced 1 thrombotic experience should be treated with anticoagulant therapy for a period of 3 months to 1 year

Pts who’ve experienced recurrent episodes or strong family hx long term anticoagulant therapy

Recombinant activated protein C for acquired protein C deficiency

Avoid immobilization to greatest extent possible

Compression stockings

Vena caval filter

Question 8

Herparin

Answer 8

Glycosaminoglycan extracted from porcine intestinal mucosa or bovine lung

Herparin increases rate of thrombin-antithrombin reaction at least a thousand fold

Its an anticoagulant ( low molecular weight herparin) by inhibition of factor Xa by antithrombin

Antidote is Protamine Sulfate

Given IV or subcut

Safe in pregnancy

Question 9

Adverse effect of herparin and Warfarin

Answer 9

Bleeding( hence given slowly at 1mg/100units and not as bolus)

Herparin induced thrombocytopenia

Osteoporosis

Warfarin antidote is Vit K

Drug drug interactions

Bleeding

Birth defect hence not safe in pregnancy

Skin necrosis

Question 10

INR

Answer 10

International Normalized ratio = Pt ratio raised to ISI( international sensitivity index)

PT isn’t standardized, not specific for the reagent being used.

Question 11

Proximal and Distal DVT and rates of investigations