hemostasis

Primary Hemostasis

100

Name the 3 steps involved in Primary Hemostasis in order 

Vasoconstriction

Platelet Adhesion 

Platelet Aggregation

200

What 2 things are necessary for platelet adhesion ? 

VonWillebrands factor 

GP1b

300

What 2 things are necessary for platelet aggregation 

Fibrinogen 

GPIIb/IIIa

400

What is the lifespan of a platelet 

7-10 days

500

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 

Coag Factors

100

What factor deficiency would you see a normal PT , normal PTT but bleeding symptoms ? 

XIII

200

What factors are vitamin K dependent? 

II, VII, IX, X 

and protein C and S 

300

What are symptoms of factor XII deficiency , what will the patients PT and PTT result likely be ? 

no bleeding 

PT - Normal 

PTT - increased 

400

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 

500

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 

testing

100

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 

200

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

300

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

400

What is the normal test therapeutic range for patients on oral anticoagulants ? 

INR = 2.5-3.5

500

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 

         

diseases

100

a cause of thrombocytopenia typically seen in children after a viral infection , spontaneous nosebleeds often resolves on its own

ITP

200

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

300

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 

400

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

• so ↑ vWF therefore ↑ platelet adhesion/aggregation
• Platelet count ↓.  more clots but more bleeding

500

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 

fibrinolysis

100

pregnancy typically causes an Increase or Decrease in Fibrinolysis ? 

decrease 

200

In what disorder will heparin not work? 

antithrombin III deficiency 

300

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 

400

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 : 

• Alpha2 Macroglobulin
• Antithrombin III
• Alpha1 Antitrypsin
• C1 Esterase Inactivator

500

The most effective Clot buster is : 

TPA - works at site of clot