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Marilah kita membiasakan diri menjadi manusia yang jujur. Laboratory Approach to Patient with Hemostasis (Bleeding) Disorders. Dr.Nadjwa ZD, SpPK-K 16 April 2012. Hemostasis.
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Laboratory Approach to Patient with Hemostasis (Bleeding) Disorders Dr.Nadjwa ZD, SpPK-K 16 April 2012
Hemostasis Is the complex process by which the body spontaneously stop bleeding and maintains blood in the fluid state within the vascular compartment. Normal hemostasis: rapid & localized.
The major role of the hemostasis system is to maintain a complete balance of the body’s tendency toward clotting and bleeding.
Primary Hemostasis (platelet plug) Secondary Hemostasis (Hemostatic Plug)
Highly integrated & regulated Hemostasis
Approach to Hemostasis Disorders • Clinical History Taking - Physical Examination - • Laboratory
Physical Examination • Petechaie • Ecchimosis • Hematom • Epistaxis • Gingival bleeding
Any Questions ???
Hemostasis Tests Screening assays in hemostasis: • Patients without any signs/symptoms preoperative • Monitoring of anticoagulant therapy • Disseminated Intravascular Coagulation • Thrombophilia • Inhibitor (Lupus Anticoagulant, Anti Phospholipid Antibody)
Tourniquet Test Bleeding Time Clotting Time Clot Retraction Platelet Count* PT* APTT* TT* Fibrinogen* Euglobulin Clot Lysis Test D-Dimer Thrombelastography Hemostasis Screening Test
Single, comprehensive hemostasis screening test Thrombelas- tography
Tourniquete Test = Capillary Resistance Test. = Rumpel Leede Test = Hess’s Test Principle : This test measures the ability of the capillaries to resist pressure. In healthy individu, the capillaries in the arm will resist a pressure of 100 mmHg. If the capillaries can not resist, they will break or rupture, tiny spot will then appear. These spots are hemorrhages or petechiae.
5 cm 5 cm TOURNIQUET TEST SYSTOLIC DIASTOLIC 100 mmHg 5 min Leave for 5 min • Normal : < 10 petechiae • > 10 petechiae abnormal, due to: • Increased capillary resistance • Decreased platelet number petechiae
BLEEDING TIME (Duke’s Method & Ivy’s Method) • Principle : The skin is incised, blood flowing out is aspirated with a filter paper, and then the time until hemostasis is measured. • Purpose : To evaluate platelet and vascular ability in performing platelet plug.
Interpretation • Time in minutes equals number of blots divided by 2 • When the blood spot becomes 1 mm or smaller, stop the stop watch. • If the bleeding doesn’t stop in 10 min., discontinue testing. Indicate the result as 10 min or longer. • Cover the wound with a sterile gauze for a while, hemostasis should be confirmed, after which the patient may leave. • The size of the blood spot about 1 cm in diameter is desirable, but becomes larger in some cases. However bleeding usually stops for several minutes regardless of the size. • Don’t wipe off the blood. Gently touch. Note so as not to touch the wound.
CLOT RETRACTION Principle • When whole blood is allowed to clot spontaneously, the initial coagulum is composed of all elements of the blood. • With time the coagulum reduces in mass, and fluid serum is expressed from the clot, and its volume stated in %. • This is due to an action of platelets on the fibrin network.
BEDSIDE CLOTTING TIME Principle : • Record the time interval from the blood contact with glass surface, until fibrin network is performed at the room temperature. Sample : • Capillary blood
!....!....!....!....!....!....!....!....!....!....!....!....!....!....!....!....!....!....!....!....!....!....!....!....!....!....!....!.... Clotting Time : Lee & White blood 3 ml 1 cc 1 cc 1cc 37oC N : 5 – 11 min
Coagulation Screening Tests: Related to the Coagulation Cascade
Prothrombin Time (PT) • Screening test for the extrinsic and common pathways of coagulation (factors II, VII, V, X). • Limited sensitivity to fibrinogen. • Normal range : 11-13 sec
INR (International Normalized Ratio) To overcome some of the difficulties with the variability of thromboplastin normalizing the responses of thromboplastin reagents against an international standard. • INR = { -----------} PTpat ISI PTn
ISI(International Sensitivity Index) • Needs to be developed for each thromboplastin reagent and instrument combination used in performing PT and calculation of INR. • Ideal reagent ISI < 1.7
Activated Partial Thromboplastin Time (aPTT) • Screening test for the intrinsic and common pathways of coagulation (factors XII, XI, IX, VIII, X, V and II). • Limited sensitivity to fibrinogen. • Maybe normal in some cases of vWD • Normal range : < 35 sec
Thrombin Time (TT) • Identified stage 3 defects in the coagulation mechanism • Clinical significant Prolonged TT : • Decreased fibrinogen concentration • Presence of dysfunctional fibrinogen • Presence of heparin • Presence of FDP
Prothrombin Time Principle of the test : • Time required for the formation of a fibrin clot when plasma is added to a thromboplastin-calcium mixture. • Measure extrinsic and common pathway (FI,II,V,VII,X)
Prothrombin Time Purpose : • Evaluation of coagulation disorders • Evaluation of liver function • Monitoring anticoagulan therapy Result inform in : • Second • Percent • INR (International Normalized Ratio) PT prolonged if coagulation factors in extrinsic pathway decreased <30%
APTT Activated Partial Thromboplastin Time (APTT) Principle of the test : • Time required for the formation of a fibrin clot without additional thromboplastin. • Measuredintrinsicand common pathway
D-Dimer Test Principle : Is the time required for the formation of a fibrin clot if thrombin is added. Affected by : • Concentration and fibrinogen reaction • Inhibitor (also FDPand heparin).
Thromboelastography • Screening & control therapy • Easy to perform, no reagent needed, fast • Record clot formation and converse to graph • TEG ruler • Conversion table
1. TEG NORMAL PATTERN m. a 20 mm r k r = reaction time (start to amplitudo 1 mm) k = coagulation time (end of r to amplitudo 20 mm) m .a = maximum amplitudo (mm) m . e = maximum elasticity 100 x a m . e = ------------- 100 - a
2. THROMBOCYTOPENIA r = normal k = normal/prolonged m.a. = shortened m. a r k 3. HYPERFIBRINOLYSIS r = normal k = normal m.a. = previously normal, but suddenly become shortened m.a r k