hemostasis

Question 1

bernard soulier syndrome

Answer 1

genetic deficiency of GPIb. platelet adhesion is impaired mild thrombocytopenia with enlarged platelets.

Question 2

glazmann thrombasthenia

Answer 2

genetic deficiency GIIb/IIIa. platelet aggregation is impaired.

Question 3

name two other things that impair function

Answer 3

ASA and uremia

Question 4

hemophilia A

Answer 4

factor VIII. X-linked. predominant males. can be de novo. there will be deep tissue bleeding. increase in the PTT and normal PT. give recombinant VIII. a mixing study will show correction!

Question 5

hemophilia B

Answer 5

factor IX. decreased. PTT elongated.

Question 6

anti-factor VIII

Answer 6

extremely similar to hemophilia A. there will increased PTT. need to do a mixing study. the study will show NO correction with mixing study

Question 7

von willebrand

Answer 7

most common genetic deficiency. there are decreased levels. there will be issues with platelet adhesion. mild mucosal and skin bleeding. increased bleeding time. PTT will be increased. VWf stabilizes factor VIII. generally dont have issues with secondary hemostasis. PT normal. abnormal ristocetin.

Question 8

treatment for VWf

Answer 8

desmopressin. increases the release of von willebrand from endothelial cells.

Question 9

vitamin K deficiency

Answer 9

required for gamma-carboxylation of 2, 7 9, 10, C and S. vitamin K is activated by epoxside reductase.

Question 10

who gets vitamin K deficieny

Answer 10

newborns, malabsorption, longterm antibiotic therapy, liver failure.

Question 11

how do we measure liver failure effect on hemostasis

Answer 11

PT

Question 12

HIT

Answer 12

heparin forms a complex with platelet factor 4. this can cause autoantibody IgG results in consumption of platelets. fragments of platelets causes thrombosis.

Question 13

DIC

Answer 13

pathological activation of the coagulation cascade. results in blocking of small vessels. consumption of platelets and factors. mucosal surfaces, GI tract, etc. almost always secondary -sepsis, adenocarcinoma (mucin), leukemia, rattlesnake bite.

Question 14

labs for DIC

Answer 14

low platelets, coagulation factors low so PTT/PT low. fibrinogen consumed, microangiopathic hemolytic anemia. with schistocytes. there will elevated fibrin split products. (D-dimer)

Question 15

hallmark for DIC (best screening test)

Answer 15

D dimer

Question 16

fibrinolysis

Answer 16

due to plasmin overactivity resulting in excessive cleavage of fibrinogen. resembles DIC. PTT/PT high, bleeding time high. platelet normal. fibrinogen split products will be elevated, but D-dimer normal. (aminocaproic acid)

Question 17

fibrinolysis causes

Answer 17

radical prostectomy (release of urokinase), cirrhosis.

Question 18

thrombus characteristics

Answer 18

lines of Zahn. attachment to the vessel wall. these distinguish from postmortem clot.

Question 19

line of zahn

Answer 19

RBC and fibrin layers that alternate.

Question 20

risk for thrombosis (virchows triad)

Answer 20

disruption of blood flow, endothelial cell damage, hypercoaguable state.

Question 21

examples for thrombosis

Answer 21

immobilization, cardiac wall dysfunction, aneurysm.

Question 22

endothelial protection from thrombosis

Answer 22

blocks subendothelial collagen. produces prostaglandin I2
NO causes vasodilation. also secretes heparin-like molecules. tPA also produced. thrombomodulin which inhibits coagulation

Question 23

causes of endothelial damage

Answer 23

cysteine levels, atherosclerosis, vasculitis.

Question 24

cystathionine beta synthase deficiency

Answer 24

high levels of homocysteine, vessel thrombus, mental retardation, lens dislocation, long slender fingers.

Question 25

hypercoaguable state

Answer 25

due to excessive procoagulant or defective anticoag proteins. present with recurrent DVT or young age. hepatic veins and cerebral veins

Question 26

protein C and S

Answer 26

inactivate factors V and VIII. this shuts down the cascade. this increases the risk of thrombosis. giving warfarin is terrible for these patients

Question 27

factor V leiden

Answer 27

mutated form of V that does not allow cleavage and disactivation by C and S.

Question 28

prothrombin 20210A

Answer 28

point mutation in prothrombin results in increased gene expression, promotes thrombus formation.

Question 29

antithrombin III def.

Answer 29

lacks antithrombin. thus there is overactivation of thrombin and thus clots. PTT does NOT rise with standard heparin dosing!

Question 30

does the PT rise with heparin,

Answer 30

yes but we don’t monitor it. we monitor the PTT

Question 31

why are contraceptives associated with thrombosis

Answer 31

because they upregulate the production of coagulation factors

Question 32

embolus

Answer 32

intravascular mass that travels through the bloodstream and occludes a down stream vessel. symptoms depend on the vessel

Question 33

thromboembolus

Answer 33

most common type of embolus.

Question 34

how do we know that a thrombus came from an atherosclerotic plaque

Answer 34

there are cholesterol clefts

Question 35

fat embolus

Answer 35

bone fracture, long bones, and soft tissue trauma. develops while fracture is still present or shortly afterward. there is dyspnea and petechiae on the skin overlying the chest.

Question 36

caisson disease

Answer 36

chronic gas embolus.

Question 37

why are PE usually silent.

Answer 37

dual blood supply and thrombus is usually small and self-resolves

Question 38

clinical signs of PE

Answer 38

shortness of breath, hemoptysis, pleuritic chest pain, and pleural effusion. V/Q mismatch, perfusion is normal. spiral CT shows a vascular filling defect in the lung.

Question 39

most common source of systemic emboli

Answer 39

left heart. most commonly goes to the lower extremities