Acquired bleeding disorders

Question 1

Name the main acquired bleeding disorders

Answer 1

• Vitamin K deficiency
• Liver disease
• Iatrogenic
• Disseminated intravascular coagulation
• Acquired inhibitors
• Massive transfusion syndrome

Question 2

What does factor II become?

Answer 2

II–> thrombin–> fibrinogen–> fibrin–> fibrin degradation products

Question 3

How is an inhibitor or a bleeding deficiency problem diagnosed?

Answer 3

• Mix patient & normal plasma
• Correction= deficiency
• No correction= inhibitor

Question 4

Describe vitamin K deficiency

Answer 4

• Deficient factors 2, 7, 9, 10
• Functional deficiency
• Causes: obstetrics, jaundice, broad spectrum antibiotics, neonates, prolonged nutrient deficiency

Question 5

What are types of impaired haemostasis in liver disease?

Answer 5

• Excessive plasmin activity
• Thrombocytopenia
• Platelet dysfunction
• Reduced plasma conc of all coagulation factors except 8
• Delayed fibrin monomer polymerisation due to altered fibrinogen glycosylation
• Treated with fresh frozen plasma/platelet transfusion

Question 6

What are the causes of haemostatic abnormalities in massive transfusion?

Answer 6

• Dilutional depletion of platelets & coagulation factors
• Underlying disease-liver/renal drug treatment
• DIC-trauma, head injury, prolonged hypotension

Question 7

Describe the dilutional effects of haemostasis

Answer 7

• Thrombocytopenia
• Citrate toxicity
• Coagulation factor depletion (5,8 & fibrinogen)
• Hypocalcaemia

Question 8

What is the pathophysiology of DIC? How is it treated?

Answer 8

• Consumption of platelets & clotting factors
• Activation of fibrinolysis
• Microangiopathic haemolysis
• Microvascular thrombosis: tissue ischaemia & organ damage
• Disruption in balance of procoagulant & anticoagulant mechansims
• Treat underlying condition-antibiotics,obs, folic acid, it K, maintain tissue perfusion

Question 9

What are acute causes of DIC?

Answer 9

• ABO incompatible transfusion
• Fulminant liver disease
• Sepsis
• Trauma/tissue necrosis
• Obstetrics complications

Question 10

What are chronic causes of DIC?

Answer 10

• Malignancy
• End stage liver disease
• Severe localised intravascular coagulation
• Obstetrics: retained dead foetus

Question 11

What drugs can interact with oral anticoagulants?

Answer 11

• Corticosteroids
• Sulphonylureas
• NSAIDs
• Ampicillin
• Erythromycin
• Cephalosporins

Question 12

Which drugs antagonise the effects of warfarin?

Answer 12

• Spironolactone
• Vitamin K
• Rifampicin
• Cholestyramine

Question 13

What are the causes of haemostatic abnormalities in renal disease?

Answer 13

• Changed interaction of different components of the coagulation system
• coagulation cascade, platelets and vessel wall

Question 14

What are recommendations for reversal of oral anticoag treatment?

Answer 14

• Life threatening= Vit K IV, four factor concentrate/PCC, octaplex
• Non major= withhold warfarin, Vit K IV
• INR>8 no haemorrhage= withhold warfarin, vit K orally

Question 15

How are the following monitored:
warfarin
heparin
fondaparinux
aspirin
fibrinolytic agents

Answer 15

• W=INR
• H= APTT test sensitive anti-thrombin not routinely required
• F=Haematocrit, PT, platelet count, serum creatinine
• A=CBC, platelets, PT, BUN, serum creatinine
• FA=

Question 16

How is bleeding/overanticoagulation managed?

Answer 16

• Stop infusion

- Consider protamine (neutralises heparin)

Question 17

What are the complications of the following:
warfarin
heparin
fondaparinux
aspirin
fibrinolytic agents

Answer 17

• W= excess bleeding, bruising
• H= VTE
• F=rash, itching, mild bleeding
• A= same as warfarin
• FA=same as warfarin

Question 18

What is the mode of action of aspirin?

Answer 18

• Impede clotting by blocking prostaglandin synthetase action
• prevents formation of the platelet-aggregating substance thromboxane A2

Question 19

What is the mode of action for warfarin?

Answer 19

Inhibiting the synthesis of vitamin K-dependent clotting factors and the anticoagulant proteins C and S.

Question 20

What is the mode of action for heparin?

Answer 20

• Inactivating thrombin & activated factor X through an antithrombin-dependent mechanism.
• Binds through a high-affinity pentasaccharide