1. Interactive Session on Clotting Profile Dr P T R Makuloluwa MBBS (Col), MD (Anaesthesiology), FRCA (Lond)

2. What are the steps in haemostasis ?  vascular response  formation of platelet plug  formation of fibrin clot

3. Formation of platelet plug  what tests can be done to assess the formation of platelet plug ?  platelet counts & bleeding time (BT)  what conditions are likely to interfere with this function ?  thrombocytopaenia, thrombasthenia  dengue fever (  platelet count)  what clinical features are seen in these patients with defective function of platelets ? purpuric rash, ecchymosis, bleeding gums

4. Fibrin clot formation  name the clotting pathways involved  intrinsic & extrinsic pathways  what clotting tests are available to assess the integrity of pathways ?  intrinsic pathway - APTT  extrinsic pathway - PT, INR  what pathway is defective in haemophiliacs  intrinsic pathway (due to deficiency of Factor V111)

5.  how could deficiency of vitamin k interfere with clotting ?  vitamin k is necessary for the hepatic synthesis of Factors 11, V11, IX, X  deficiency of vitamin k, therefore interferes with the activity of both pathways

6. Fibrinolytic system  what tests can be used as indicators of of excessive fibrinolysis ?   FDPs (fibrin degradation products)  D – dimers  what agents can be used for fibrinolysis ?  t - PA, streptokinase, urokinase  how does a patient with excessive fibrinolysis present ?  excessive bleeding

7. Practical on Clotting Profile Objectives:  Skills Student should be able to  perform the ward tests to measure BT & CT  interpret the results of clotting profile with reference to haemostatic derangements  analyze the results of clotting profile in the light of underlying clinical condition

8. Scenario 1  A diagnosis of dengue fever was made in a child presented with bleeding gums & a purpuric rash on the skin  His bleeding time was 15 min.  what is the likely reason for prolonged BT low platelet counts  what other test could confirm the abnormality in haemostasis? platelet counts

9. Clinical Scenario 2  5 years old child presented with pain & swelling of right knee following a trivial injury  a similar episodes in the past with a diagnosis of haemophilia  comment on the haemostatic abnormality in this child  clotting defect due to deficiency of Factor VIII

10.  comment on the likely results of clotting profile  platelet count: normal  bleeding time: normal  clotting time : prolonged  PT : normal  APTT: prolonged  what is the reason for prolonged APTT?  an abnormality in intrinsic clotting pathway

11. Clinical Scenario 3  A heavy alcoholic having cirrhosis of liver presented with multiple bruises on the skin & bleeding from the nose (epistaxis)  what abnormalities are expected in the clotting profile & why?  prolonged PT  increased INR ratio due to defective extrinsic clotting pathway

12.  prolonged APTT due to defective intrinsic pathway deficiency of all the clotting factors synthesized by liver

13. Scenario 4  a patient with an artificial heart valve, on anticoagulant warfarin, awaiting major surgery  what are the most useful clotting tests to assess his state of coagulation & why?  PT  INR defective extrinsic pathway warfarin inhibit the synthesis of vitamin k dependent factors II, VII,IX,X

14. Scenario 5  a patient on heparin, following an epidsode of deep vein thrombosis after surgery for fractured hip bone  what clotting test is useful in the assessment of haemostatic mechanisms & why ?  APTT heparin affects the activity of intrinsic pathway