Mixing Studies Flashcards
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Principle of mixing studies/substitution studies
Substitution studies may be performed by mixing correction reagents (adsorbed plasma/aged serum), with the patient’s plasma and then performing PT and APTT to identify a specific factor deficiency.
Adsorbed plasma is rich in factors …
V, VIII, XI, XII (5 8 11 12)
Factors absent in adsorbed plasma.
X, IX, VII, II (1972)
Aged serum is rich in factors …
7, 9 ,10, 11, 12
Factors absent in aged serum
1, 2 , 5 , 8, 13
(Iyang klase kay 1 to 5 tas 8 bisag 13 pa siya)
PT Reagent
Tissue thromboplastin
APTT Reagent
partial thromboplastin with activator, calcium chloride
In mixing studies, how many percent of sodium chloride is needed?
0.85%, (w/v)
Type of control plasma for mixing studies
Normal control plasma
Spx for mixing studies
Fresh citrated plasma
Before performing the substitution test, what should be performed and why?
Test for circulating anticoagulants to rule out presence of an inhibitor
Test for Factor I deficiency
Thrombin Time
Factors belonging to the Instrinsic Pathway but not detected in mixing studies.
Prekallikrein & High Molecular Weight Kininogen (HMWK)
Intrinsic Pathway factors in mixing studies
12, 11, 9, 8
Factor/s belonging to the Extrinsic Pathway
7
A factor belonging to the extrinsic pathway appearing only with injury
Factor 3
Factors belonging to the common pathway
10, 5, (Prothrombin) 2, (Fibrinogen) 1
PT is prolonged; APTT is normal
The missing factor belongs to ….
Extrinsic pathway
PT is normal; APTT is prolonged
The missing factor belongs to …
Intrinsic Pathway
Both PT and APTT are prolonged
The missing factor belongs to …
Common Pathway
When adsorbed plasma is treated with Barium Sulfate or Aluminum Hydroxide, these factors will be lost.
Vitamin K Dependent Factors (1972)
Labile coagulation factors that disappears when spx is left unprocessed after 2 hours.
Factors 5 and 8
Most commonly used reagents
Fresh plasma
Adsorbed plasma
Aged serum
Factors present in fresh plasma
All
