Interactive Session onClotting Profile

Dr P T R Makuloluwa

MBBS (Col), MD (Anaesthesiology),

FRCA (Lond)

What are the steps in haemostasis ?

vascular response

formation of platelet plug

formation of fibrin clot

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

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)

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

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

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

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

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

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

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

prolonged APTT

due to defective intrinsic pathway

deficiency of all the clotting factors

synthesized by liver

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

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