Coagulaton Tests and Fibrinolysis Flashcards
Manual techniques
Tilt tube, wire loop
REQUIRES GENTLE TILTING OF THE TUBE BACK AND FORTH AT THE RATE OF ABOUT ONCE PER SECOND UNTIL A FIBRIN WEB IS FORMED.
TILT TUBE METHOD
EMPLOYS THE USE OF A WIRE LOOP THAT IS PASSED THROUGH THE MIXTURE AT THE RATE OF TWO SWEEPS PER SECOND UNTIL A FORMED
CLOT ADHERES TO THE LOOP.
NICHROME WIRE LOOP TECHNIQUE
Automated techniques
MOVING PROBE, OPTICAL DENSITY
A CLOT IS DETECTED EITHER BY USE OF A ______ IMMERSED IN THE MIXTURE THAT IS TRIGGERED BY CLOT FORMATION
MOVING PROBE
A CLOT IS DETECTED EITHER BY USE OF A MOVING PROBE OR BY THE CHANGE IN ____ OF THE MIXTURE WHEN A CLOT FORMS.
OPTICAL DENSITY
SCREEN SECONDARY HEMOSTASIS
(INTRINSIC AND COMMON PATHWAY)
LEE AND WHITE METHOD
LEE AND WHITE METHOD principle
EXPOSE BLOOD TO A NEGATIVELY CHARGED SURFACE
NV FOR LEE AND WHITE METHOD
5-15 min
The surface of the glass tube initiates the Clotting process. This test is sensitive to the factors involved in the intrinsic pathway
Clotting Time - Slide Method
(Intrinsic)
The expected range for Slide Method Clotting Time is
4-10 min.
LABORATORY SCREENING
• PROTHROMBIN TIME
• ACTIVATED PARTIAL THROMBOPLASTIN TIME (APTT)
IS A USEFUL SCREENING PROCEDURE FOR THE EXTRINSIC AND COMMON PATHWAY.
PROTHROMBIN TIME
Sample for PROTHROMBIN TIME
CITRATED PLASMA
REAGENT: PROTHROMBIN TIME
TISSUE THROMBOPLASTIN
0.025 MOL/L SOLUTION OF CALCIUM CHLORIDE.
NORMAL RANGE: PROTHROMBIN TIME
10-15 SEC
MEASURES ALL FACTORS IN THE INTRINSIC
AND COMMON PATHWAY EXCEPT FACTOR XIII (fibrin stabilizing) AND PLATELETS.
ACTIVATED PARTIAL THROMBOPLASTIN TIME (APTT)
ACTIVATED PARTIAL THROMBOPLASTIN TIME (APTT) SAMPLE:
CITRATED PLASMA
ACTIVATED PARTIAL THROMBOPLASTIN TIME (APTT) REAGENT:
PARTIAL THROMBOPLASTIN, CALCIUM CHLORIDE, ACTIVATORS
ACTIVATED PARTIAL THROMBOPLASTIN TIME (APTT) ACTIVATORS:
SILICA, KAOLIN, ELLAGIC ACID, CELITE
ACTIVATED PARTIAL THROMBOPLASTIN TIME (APTT) NORMAL RANGE:
28-46 SEC
MEASURES THE AVAILABILITY OF FUNCTIONAL FIBRINOGEN OR DECREASED AMOUNT (75-100 MG/DL). AFFECTED BY HEPARIN.
THROMBIN TIME (TT)
THROMBIN TIME (TT) PRINCIPLE:
MEASURED THROMBIN IS ADDED TO PLASMA AND TIME FOR FIBRIN CLOT
FORMATION IS RECORDED.
FIBRINOGEN DECREASED AMOUNT
(75-100 MG/DL).
THROMBIN TIME (TT)
10-14 SEC (BROWN)
Thrombin time is affected by
Heparin
SAME AS THROMBIN TIME BUT NOT AFFECTED BY HEPARIN.
REPTILASE TIME
IS AN ENZYME FOUND IN THE VENOM OF THE BOTHROPS ATROX SNAKE THAT CAN CONVERT FIBRINOGEN O FIBRIN.
REPTILASE (ATROXIN)
SNAKE THAT CAN CONVERT FIBRINOGEN O FIBRIN.
BOTHROPS ATROX SNAKE
TIME IS RECORDED AS CLOT IS FORMED AFTER REPTILASE IS ADDED TO PLASMA.
REPTILASE TIME
REPTILASE TIME NV
10-15 SEC
USED TO DETECT DEFICIENCIES OF THE COMMON PATHWAY (FACTORS X, V, II AND I)
STYPVEN TIME (RUSSELL’S VIPER VENOM TIME)
IS A THROMBOPLASTIN LIKE SUBSTANCE THAT ACTIVATES FACTOR X.
STYPVEN
STYPVEN TIME (RUSSELL’S VIPER VENOM TIME) NV:
6-10 SEC
COMMON PATHWAY FACTORS
(FACTORS X, V, |I AND I)
DETECTS FACTOR XIII DEFICIENCY
DUCKERT’S TEST/ 5M UREA SOLUBILITY TEST
IN DUCKERT’S TEST/ 5M UREA SOLUBILITY TEST CLOT FORMED AFTER COAGULATION IS ADDED WITH ___
5M UREA
SUBSTITUTE FOR 5M UREA
• 1% MONOCHLORACETIC ACID
• 2% ACETIC ACID
Last phase of coagulation cascade
Fibrinolysis
IT IS THE SYSTEMIC,
ACCELERATING HYDROLYSIS
OF FIBRIN BY PLASMIN
FIBRINOLYSIS
FIBRINOLYSIS IS THE SYSTEMIC, ACCELERATING HYDROLYSIS OF FIBRIN BY
PLASMIN
Functions of plasmin
-Promotes Cell Migration
-Remodels ECM
-Degrades Fibrin
‘Other Coagulation tests
- Thrombin time
- Reptilase time
- Stypven Time (Russell’s Viper Venom Time)
-Duckerts test / 5 M urea solubility test
SERINE PROTEASE ZYMOGEN;
PLASMINOGEN
PLASMINOGEN ACTIVE FORM WHICH DIGESTS FIBRIN AND FIBRINOGEN
PLASMIN
SECRETED BY ENDOTHELIUM AND
ACTIVATES PLASMINOGEN
TISSUE PLASMINOGEN ACTIVATOR (TPA)
SECRETED BY KIDNEYS AND ACTIVATES PLASMINOGEN
TISSUE PLASMINOGEN ACTIVATOR (TPA)
SECRETED BY KIDNEYS AND ACTIVATES PLASMINOGEN
UROKINASE
FROM ENDOTHELIUM, INHIBITS ТРА
PLASMNIOGEN ACTIVATOR INHIBITOR 1 (PAI-1)
INHIBITS PLASMIN
A2-ANTIPLASMIN
SUPPRESSES FIBRINOLYSIS
THROMBIN ACTIVATABLE FIBRINOLYSIS INHIBITOR
THE FIBRIN FORMED IS COMPOSED OF TWO DOMAINS:
D AND E
- PLASMINOGEN IN PLASMA IS ACTIVATED BY TPA AND UROKINASE INTO ACTIVE ENZYME
____
PLASMIN
- PLASMIN, THEN CLEAVES THE PEPTIDE BONDS ON THE ___ AND ___ AMINO ACID THAT CONNECTS THE TWO DOMAINS.
ARGININE AND LYSINE
- THE FIBRIN DIGESTED WILL THEN FORM THE FIBRIN DEGRADATION PRODUCTS (FDPS)
NAMELY:
FRAGMENT X (D-E-D),
FRAGMENT Y (D-E),
FRAGMENT D,
FRAGMENT E,
AND FRAGMENT D-D (D-DIMER).
