Test for coagulation disorders• Thromboplastin + calcium + prothrombin ThrombinThrombin + Fibrinogen Fibrin ( clot)Coagulation time : A. Lee & White method 1. 3ml of blood in sterile syringe with needle washing

with physiological saline , record the time and place each 1ml in tube then tilt the 1st & 2nd tubes at 30 second intervals until coagulation occurred then 3rd tube in same manner , the elapsed time between the first appearance of blood in syrange and clot formation in the 3rd tube . ( most accurate )

• B. Capillary tube method :1. Puncture the skin & fill special capillary tube with

blood , noting the time when blood first appears .2. Holding the tube between the thumb and index

finger of both hands , gently break the tube every 30second until strand of fibrin is seen

C. Slid method :

Bleeding time

• Make small Deep puncture in the skin with lancet and note the time when blood appears .

• Remove the drope of blood with filter paper every 30 second ( not touch the skin )

Prothrombin Time : Oxalated plasma is cloted by the addition of calcium in presence of excess throboplastin , the time required for clotting of plasma is directed related to speed of conversion of prothrombin to thrombin and depend upon the level of plasma prothrombin .

Prothrombin deficiency

• Coagulation time , bleeding time and prothrombin time are prolonged , thrombocyte are normal .

1. Liver disease : sever hepatocellulr damage 2. Vitamin K deficiency .