Dr Ambika Jawalkar
I. Platelet disorders
II. Coagulation disorders/defective coagulation mechanism
III. Vascular disorders (Non-thrombocytopenic purpura)
Thrombocytopenic purpura – deficiency of platelets
*essential / idiopathic(ITP)*secondary
Thrombasthenia – functional disorder of platelets (defect in adhesion / aggregation)
eg: aspirin, large doses of penicillin, von Willibrand’s disease
Deficiency of clotting factors* Hemophilia
Vitamin K deficiency Anticoagulant overdose Disseminated intravascular clotting (DIC)
Drug induced damage to capillary wall Deficiency of vitamin C – Scurvy Allergic purpura Infections Senile purpura Connective tissue diseases
Group of bleeding disorders Characteristic features are,
*purple-colored petechial haemorrhages*bruises in the skin
CAUSES:1. Platelet disorders
Thrombocytopenic purpura – primary, secondary
Thrombosthenic purpura – vWD1. Vascular disorders – non-
thrombocytopenic purpura
“group of disorders occouring due to heriditary deficiency of coagulation”
Characterized by bleeding tendency & increased clotting time.
Hemoplilia A – 83% cases* Factor VIII (Classic Hemophilia)
Hemophilia B – 15% cases* Factor IX (Christmas disease)
Hemophilia C – 2% cases* Factor XI (PTA deficiency)
TESTS THAT DETECT DEFECTS IN THP
Bleeding time Capillary fragility test Platelet aggregation test Platelet adhesiveness test
TESTS THAT DETECT DEFECTS IN DHP Clotting time Prothrombin time Prothrombin
consumption time Partial thromboplastin
time (PTT) Activated partial
thromboplastin time (aPTT)
Thrombin time Clot retraction time
Time lapse between the skin prick and arrest of bleeding
Estimated by Duke’s method & Ivy’s method
Normal valuesby Duke’s method – 1-6 min.by Ivy’s method – 3-6 min.
BT is prolonged in Purpura & normal in Hemophilia
Time between skin prick & formation of first fibrin thread
Estimated by Capillary tube method & Lee-White method
Normal valuesby capillary tube method is 3-6 min.by lee-white method is 8-12 min.
Prolonged in hemophila
Quick’s one stage method Commercially available tissue
thromboplastin & CaCl2 is added to oxalated or citrated plasma – incubated at 37oC
Normal value is 11-16 sec. Extrinsic system is tested here.(no platelets
involved) Used to monitor anti-coagulant therapy Increased in liver failure, vit K deficiency
Also known as KCCT – Kaolin cephalinclotting time.
Detects minute coagulation defects Normal is 40 sec. Measures intrinsic pathway Used to monitor Heparin therapy Is prolonged in Hemophilia, vWD
Measures final step in coagulation i.e, availability of functional fibrinogen
Normal is 10 sec. Is prolonged in hypofibrinogenemia,
dysfibrinogenemia, DIC & hepain therapy.
Measures time needed for contraction of an undisturbed clot.
Indicates function & number of platelets Normally begins within 2 hours and
completed within 24 hours Is retarded in thrombocytopenia Clot is small & soft in thromboasthenia