Laboratory Evaluation Secondary Hemostasis Flashcards
Tests the composite action of all plasma factors
acting simultaneously
the coagulation test
is a measure of the ability of the blood
to clot and is not influenced by the platelet functions
other than PF3
clotting time
measures only the time
required for the formation of the traces of thrombin
sufficient to produce a visible clot.
coagulation test
a. Micro Methods of coagulation test
slide or drop method
capillary or dale and laidlaw’s method
interval for checking fibrin strand in slide method
every 30 seconds
every how many seconds do we need to break capillary tube in capillary tube method
every 30 seconds and check for fibrin strands
Macro Methods of coagulation test
lee-white method or whole blood clotting time
this method of coagulation test is superior for there is less
contamination of the plasma with tissue fluids when
blood is drawn from a vein.
macro methods
principle of the lee white method
the whole blood clotting time is the time required for freshly collected blood to form a firm clot in standardized glass tubes at 37*C. Thus, the whole blood clotting time is a measure of the integrity of the intrinsic system
normal values of lee white clotting time
5-10 mns
- Advantages of Lee Whit
- More accurate and standard method.
- Test can be run with control.
Disadvantages of lee white
- It is also a rough method.
- There can be contamination of syringe or tube.
- Vigorous agitation of the tubes should be avoided as it shortens the clotting time
the principle of Activated Coagulation Time of Whole Blood
the activated coagulation time of whole blood is the time necessary for fresh blood to form a clot when incubated as 37*C in the presence of surface contact activation. This assay, like to whole blood clotting, measures overall activity of the intrinsic clotting system
normal values of Activated Coagulation Time of Whole Blood
1-2 mns
factors that may affect our coagulation test result includes
the effects of surgery
body temperature
other medicines you are taking
getting IV fluids which can dilute the blood
platelet counts and platelet functions
coagulation factor deficiencies
is a measure of intrinsic coagulation mechanism
plasma recalcification time
more sensitive method than the coagulation time of whole blood
plasma recalcification time
may reveal abnormality which is not detectable by the determination of clotting time of venous blood
plasma recalcification time
ref range of plasma recalcification time
90-250 seconds
Activated Recalcification Time employs the use of ___
0.1 ml of plt rich plasma and an activator
activator examples in Activated Recalcification
Time
0.1 ml of 0.025 M calcium chloride
0.1 ml of 1% cellite
reference range of Activated Recalcification
Time
less than 50 seconds