Primary Hemostasis
Name the 3 steps involved in Primary Hemostasis in order
Vasoconstriction
Platelet Adhesion
Platelet Aggregation
What factor deficiency would you see a normal PT , normal PTT but bleeding symptoms ?
XIII
You run Protimes on a photo-optical coag analyzer. Both your normal and abnormal controls are low and slightly out of range. Patient results seem low. Which of the following could be the problem?
a. Controls have expired
b. Incubation temperature is high
c. incubation temperature is low
d. Thromboplastin is expired
B
ITP
pregnancy typically causes an Increase or Decrease in Fibrinolysis ?
decrease
What 2 things are necessary for platelet adhesion ?
VonWillebrands factor
GP1b
What factors are vitamin K dependent?
II, VII, IX, X
and protein C and S
a patient is having pre-op blood work done. They have no history of bleeding disorder. The PT is normal and PTT is increased.
Lab performs a mixing study with normal patient plasma and the PTT is still increased. What may be the cause of the increased PTT
Lupus anticoagulant aka anticardiolipin antibody
** remember this doesn't typically cause a coag disorder in the patient but actually may cause increased risk for Thrombosis
Disease in which Platelets lack the glycoproteins IIb/IIIa receptors for platelet to platelet attachment
CD41 and CD61 are decreased
CD42b is normal
Glanzman’s Thrombasthenia
In what disorder will heparin not work?
antithrombin III deficiency
What 2 things are necessary for platelet aggregation
Fibrinogen
GPIIb/IIIa
What are symptoms of factor XII deficiency , what will the patients PT and PTT result likely be ?
no bleeding
PT - Normal
PTT - increased
What test is used to monitor oral anticoagulant, which test is used to monitor unfractionated Heparin therapy , and which test is used to monitor LMWH ( low molecular weight heparin)
Oral anticoagulant- PT
Unfractionated Heparin- PTT
LMWH- anti-Xa
a patient presents to the Emergency room in distress .. lab tests are as follows:
PT: increased
PTT : increased
Platelet count : decreased
D-Dimer : increased
TT : increased
What would you expect this patients FDP results to be?
increased
- DIC
Clot Busters include - steptokinase , urokinase and TPA. They are all plasminogen activators. What would you expect for the PT, PTT, D-Dimer , FDPs when each of these clot busters are used?
Streptokinase and Urokinase - All increased
TPA - DDimer increased , FDPs normal , PT and PTT normal to slight increase
What is the lifespan of a platelet
7-10 days
Name 3 functions of Thrombin
1. activate fibrinogen to become fibrin
2. accelerates activation of V and VIII
3. stimulates platelets to release ADP from granules causing them to aggregate
4. activates factor XIII to stabilize the clot
5. stimulates production of prostoglandins for vessel relaxation
What is the normal test therapeutic range for patients on oral anticoagulants ?
INR = 2.5-3.5
TTP (Thrombotic Thrombocytopenia Purpura)
is a rare autoimmune disorder typically seen during preg or after an infection etc
Patient's produce an autoAb that destroys what ?
ADAMTS-13 - an enzyme that cleaves vWF
Plasmin can keep lysing fibrin and fibrinogen unless it is stopped by :
a. Streptokinase
b. Thomboxane A2
c. Alpha 2 antiplasmin
d. Bradykinin
C
also :
This enzyme acts on Arachidonic acid to form prostaglandins which are acted on by thromboxane synthase to produce Thromboxane AII - this stimulates platelets to aggregate/ adhere and causes vasocontriction.
This enzyme is also what Aspirin acts on to decrease platelet function for the life of the platelet
Cyclo-oxygenase
A prolonged APTT is corrected with factor
VIII deficient plasma but not with factor
IX deficient plasma. Which disease does this patient likely have ?
a. Lupus anticoagulant
b. Hemophilia A
c. Hemophilia B - Christmas disease
d. Factor XII deficiency
C
describe the results for platelet aggregation test in regard to VonWillebrands disease , Glanzmann's thombasthenia , and Bernard soulier syndrome by looking at the curves with Ristocetin as the agonist vs all other agonists.
vonWillebrand's- all normal except ristocetin abnormal
Glanzmann's thombasthenia all abnormal except ristocetin normal
Bernard-Soulier/abnormal - all normal except ristocetin abnormal
In a patient with Factor V leiden - their factor V has a mutation .. explain what this mutation causes and what you would expect the patient's PT/PTT results to be
causes the factor V to be resistant to Protein C .. this will cause patient to be at increase risk of thrombosis.
PT/ PTT are normal - factor V acts fine for coagulation
The most effective Clot buster is :
TPA - works at site of clot