Lab Testing
What is the proper concentration of sodium citrate used in hemostasis testing?
AND what is the ratio of blood: anticoagulant
3.2%
9:1
What tests could be used to screen for disorders of primary hemostasis?
platelet count (for quant defects)
PFA or platelet agg (for qualitative defects)
Antithrombin is greatly accelerated by what?
Heparin
T/F
The Fibrinogen Family is Vitamin K Dependent
False
Prothrombin Family is Vitamin K Dependent
32 year old female with history of heavy menorrhagia.
vW Ag = 24%
RCOF = 20%
VIII = 30%
IX = 98%
VWD
APTT / PT
A common bleeding disorder that often leads to mucosal bleeding - defined by aggregation studies that show no aggregation with Ristocetin.
VWD
What is the dual function of Protein C?
inhibit coagulation and stimulate fibrinolysis
(destroy V and VIII, inhibits an inhibitor (TPAI))
T/F
Factor XIII is known as a transglutaminase?
True
Patient presents with easy bruising and joint pain
APTT 45.0
PT 13.0
APTT MIX 42.0
VIII 30%
vWF Ag 90%
IX 99%
Hemophilia A
A mixing study for PTT that corrects indicates a factor ____ while a mixing study for PTT that does not correct indicates a factor _____
deficiency / inhibitor
Disorder of platelet aggregation characterized by a defective GPIIbIIIa receptor that results in abnormal aggregation with all agonists except ristocetin
Glanzmann's
Patient has modestly prolonged aPTT and normal PT. Personal and family history was negative for bleeding. The most likely cause for the prolonged aPTT is an interference with phospholipid which can be shown in the assays DRVVT and PTT-LA.
What is Lupus Anticoagulant?
T/F
A Lupus Anticoagulant is an example of a specific inhibitor
Patient presents with bleeding and slight jaundice
APTT = 60.0
PT = 20.0
Mixing studies = correct to normal
VIII = 120%
IX = 35%
AST and ALT = abnormal
Liver Disease
test measured by turbidimetric methodology containing latex beads coated with antibodies specific for this terminal product of fibrinolysis
D-Dimer
Clot solubility in monochloroacetic acid is the principle of which factor assay?
XIII
What is Activated Protein C Resistance and what is the most common cause?
Cannot cleave factor V, FVLeiden
T/F
An underfilled tube (or short draw) will lead to shortened APTT results.
False (prolonged)
Patient presents with DVT after a sports injury
APTT and PT = normal
Mixing studies = not indicated
PC = 100%
PS = 105%
ATIII = 99%
Blood Type O
Fibrinogen = Normal
Factor V Leiden
A thrombin time of 28 seconds that corrects when using protamine sulfate is indicative of what?
patient on heparin
What are the three zones of platelets and list their basic function:
1. peripheral - adhesion/aggregation (glycoproteins)
2. sol-gel - contraction, support (shape change)
3. organelle - storage and secretion
What disorder occurs as a result of this: PF4 is released during platelet activation, binds nonspecifically to heparin, antibody attacks the complex and platelet counts will decrease significantly over 5-14 days
What should we do?
Heparin Induced Thrombocytopenia
Stop the Heparin
T/F
Thrombin has only three main functions
False (5)
●Fibrinogen → FIBRIN
●Activates XIa
●XIII → XIIIa
●Enhances factors V and VIII activity
●Aggregates more platelets
Patient presents with bleeding at IV site and GI bleeds on scan
PT = 18.0s
aPTT = 45.2s
TT = 25s
FIB = 105 mg/dL,
PLT = 65
D-DI positive
DIC