BLEEDING TIME AND CLOTTING TIME.pptx

bleeding time and clotting time are important tests done to detect the disorders related to haemostasis

1. BLEEDING TIME & CLOTTING TIME Mithun Venugopal. A Haematology & Transfusion Medicine

2. TESTS FOR HAEMOSTASIS AND COAGULATION TESTS FOR VASCULAR COMPONENET C apillary fragility test Bleeding Time (BT) TESTS FOR PLATELET COMPONENET Platelet count Platelet adhesion test Platelet aggregation test Clot retraction test 2

3. TESTS FOR COAGULATION FACTORS Clotting Time (CT) Prothrombin Time (PT) Activated Partial Thromboplastin Time (APTT) Thrombin Time (TT) Factor XIII screening Specific tests- factor assays, mixing studies TESTS FOR FIBRINOLYSIS Whole blood clot lysis test Euglobulin lysis test FDP and D-Dimer 3 TESTS FOR HAEMOSTASIS AND COAGULATION

4. BLEEDING TIME First functional platelet evaluation test. Introduced by duke in 1900. Used to detect defects in primary hemostasis. Used as a screening test for vascular disorders as well as platelet disorders . 4

5. Bleeding time is defined as the time taken for a standard skin wound to stop bleeding ,upon vessel injury , platelets adhere and form a haemostatic platelet plug. Bleeding time measures the ability of the platelets to arrest bleeding and therefore measures platelet number and function. 5 BLEEDING TIME

6. PRINCIPLE A standardised incision is made on the volar surface of the forearm. The time the incision bleeds is recorded. Cessation of bleeding indicate the formation of hemostatic plug. Depends on the adequate number of platelets and on the ability of the platelets to adhere to the subendothelium. 6

7. METHODS Duke’s Method Ivy’s Method Standard Template Method 7

8. IVY’S METHOD REQUIREMENTS: BP cuff Disposable lancet Stop watch Filter paper Spirit/alcohol 8

9. PROCEDURE Clean the inner aspect of the fore arm. Place a BP cuff on the upper arm , inflate to 40 mm of mercury. Select an area on the volar surface which is devoid of veins. Should be performed at room temperature. A disposable lancet with a point of about 3mm /No.11 bard parker surgical blade is used. 9

10. PROCEDURE Two skin punctures 3mm deep is made. Stopwatch is started as soon as the bleeding starts in each wound. Using the edge of a filter paper (Whatman No:1) , blot the blood accumulated over the wound without touching the wound. The time from which incision was made to the time at which the bleeding stops to stain the filter paper is taken. 10

11. PROCEDURE The average of the 2 bleeding time is taken. The BP cuff is removed. The puncture wounds are cleaned. Sterile bandage is applied. Longer bleeding time-puncture of superficial veins. 11

12. PROCEDURE If bleeding continues more than 15 min-apply pressure Repeat the bleeding time on other arm. Report-greater than 15 min. Reports correlated with platelet count. Reference range: 2-7 minutes. 12

13. ADVANTAGE Standardized method. More accurate. 13

14. LIMITATIONS Not a very reliable test. The puncture wound may close before the cessation of bleeding. 14

15. STANDARD TEMPLATE METHOD More standardized method. Uses a glass or plastic template. Allows the lancet to make a cut-11 mm long and 1mm deep. 15

16. PROCEDURE 16

17. PROCEDURE 17

18. PROCEDURE 18

19. ADVANTAGES Test is very sensitive and reproducible. Detects even minor alterations in platelet function. 19

20. DUKE’S METHOD Easy to perform Requires minimal equipment Requirements: Alcohol Sterile lancet Stopwatch Filter paper 20

21. PROCEDURE Clean the finger tip with alcohol sponge. Infants-heel of foot. Make a deep puncture with sterile lancet. Start the stop watch. Using filter paper blot the drop of blood coming out from incision. 21

22. PROCEDURE When bleeding ceases stop the stop watch. Count the number of drop on the filter paper. Multiply by 30 sec. Report the closest minute. If the cut bleeds more than 10 minutes, discontinue the test. 22

23. ADVANTAGE & DISADVANTAGE ADVANTAGE: The ear lobule contain abundant subcutaneous tissue and is vascular. Flow of the blood is quite good. Normal bleeding time-3-5 minute. DISADVANTAGE: Difficult to get a standardized wound. 23

24. VARIABLES AFFECTING BLEEDING TIME Patients with thrombocytopenia(<100×10 9 /L) Will have increased BT. Aspirin, penicillin, cephalothin prolongs BT. Pediatric patients and neonates –smaller incisions are required. pressure -20 mm of Hg. Anemia prolongs the bleeding time. 24

25. CLINICAL SIGNIFICANCE Prolonged BT is seen in: Thrombocytopenia Glanzmann's thrombasthenia Storage pool disease Bernard – Soulier syndrome Afibrinogenemia Severe hypofibrinogenemia Vascular disorders Aspirin 25

26. CLINICAL SIGNIFICANCE Aplastic anemia A/c leukemia Liver diseases Von Willebrand disease DIC Vascular abnormalities -Ehlers Danlos syndrome Severe deficiency of factor V or XI 26

27. CLOTTING TIME 27

28. CLOTTING TIME The time taken for whole blood, drawn from a vein and immediately placed in a container to clot. It measures all stages of intrinsic coagulation. It is not a very sensitive method. Avoid contamination with tissue fluid. 28

29. METHODS Modified Lee and White Method (Venipuncture Method) Capillary Method 29

30. Lee and White Method REQUIREMENTS: Cotton wool, surgical gauze soaked in alcohol, plastic syringe Test tube-acid washed(10ml) Water bath -37 c Stop watch 30

31. TWO SYRINGE TECHNIQUE-avoid interference of tissue fluid. Draw 1 ml of blood into first syringe. Without disturbing the position of the needle 2nd syringe is attached and 5ml of blood is drawn. 31 SAMPLE COLLECTION

32. Draw 3 ml of venous blood with aseptic precautions. Label 3 test tubes as No. 1, 2, 3 and keep in a water bath at 37oc . Deliver 1 ml of blood into each of the above 3 test tubes and start the stop watch. After 3 min, take out tube No 1 , tilt it every 30 seconds till a clot develops. 32 PROCEDURE

33. PROCEDURE Note the time when the tube can be inverted completely. Next examine the No 2 every 30 seconds , exactly the same way as tube No 1, till the clot forms and note the time. Finally, invert the third test tube as above till the blood clots. Stop the watch. Record the time from the moment blood is delivered in to the test tube to the complete clotting in the third tube. The clotting time of the third tube is reported as the clotting time. 33

34. PROCEDURE 34

35. ADVANTAGE & DISADVANTAGE ADVANTAGE: standard method Test can be run with control DISADVANTAGE: Not a sensitive test Only a rough method There can be contamination of syringe /tubes 35

36. NORMAL VALUE Normal value-4-11 ‘ min 36

37. SOURCES OF ERROR Faulty technique Inappropriate volume of blood Faulty venipuncture Air bubble entering the syringe Diameter of the glass tube should be uniform Always use clean glass wares and plastic syringe Vigorous agitation should be avoided. 37

38. CAPILLARY METHOD REQUIREMENTS: Disposable lancet Capillary tubing10-15 cm length and 1.5 mm diameter without anticoagulant Alcohol swab Cotton Stop Watch PPE’s 38

39. CAPILLARY METHOD PRINCIPLE: Puncture the skin, blood is taken to a plain capillary tube and stop watch started. Formation of fibrin strings is noted by breaking the capillary tube at regular intervals. The time taken for the first appearance of the fibrin string is noted. 39

40. PROCEDURE Warm up the finger for skin puncture. Make an incision with a sterile disposable lancet to depth of 3mm. As soon as blood is visible- start the stop watch. Wipe off the first drop of blood. Allow 2 nd drop of blood to flow to capillary tube. 40

41. After 2’ break off the capillary tubing,1-2 cm from the end. When a thin string of fibrin can be seen in between the broken end of the capillary tube, stop the watch and note the time. Report the time. 41 PROCEDURE

42. 42 PROCEDURE

43. ADVANTAGE & DISADVANTAGE DISADVANTAGE: This method is insensitive This method is unreliable Capillary blood always contaminated with tissue fluid ADVANTAGE: Can be performed when venous blood cannot be obtained NORMAL VALUE: 1-5 min 43

44. CLINICAL SIGNIFICANCE Prolonged clotting time seen in deficiency states involving ,Plasma thromboplastin component, plasma thromboplastin activator. Also prolonged in pt with bone marrow depression and thrombocytopenia. Deficiency of F V, VII, and X, fibrinogen, Liver diseases. 44

45. THANK YOU 45