Hemostasis

Question 0

Dense vs. alpha granules

Answer 0

• dense: serotonin, Ca, ATP, ADP

Question 1

vWB disease

Answer 1

• autosomal: I and II - dominant; III - recessive
  ~ ch 12
  ~ most common hereditary coag abnormality

Question 2

Initial vasoconstriction (2)

Answer 2

• neuro stimulated

- endothelin

Question 3

Von willebrands factor

Answer 3

• from platelets and (majority) and endothelial Weible Pilade bodies
• binds GpIb
• stabilizes factor VIII

Question 4

GpIIa/IIIb

Answer 4

• fibrinogen binder

- fibrinogen -> fibrin via Thrombin

Question 5

Co-factors req vitamin K

Answer 5

• II
• VII
• IX
• X
• C

Question 6

Thrombin function

Answer 6

• cleaves proteins off fibrinogen (fuzzy bits on top of bar bell) to activate it

Question 7

Factor XIII

Answer 7

• cross links polymerized fibrin proteins

- aka trans glutaminase

Question 8

Tissue factor (factor III, thromboplastin)

Answer 8

• initiates extrinsic coagulation

- in most cells in the body

Question 9

PT test

Answer 9

Tests factors in extrinsic pathway

Question 10

PTT (partial thromboplastin time)

Answer 10

Measures intrinsic pathway

Question 11

Protein C

Answer 11

• serine esterase
• works along with protein S (co-factor)
• PC sequesters F V and VIII
• deficiency -> hypercoagulability

Question 12

Warfarin paradox

Answer 12

• warfarin decreases all factors including PC, but its short 1/2 life it’s is decreased first so initial administration of warfarin actually increases your risk of clotting

Question 13

TTP

Answer 13

ADAMSTS13 deficiency

• normally degrades vWF monomers; defect = thrombi
• autoimmune process -> auto Ab -> adamsts13
  
  • typical pt. is 30 y/o female
• corticosteroids, splenectomy

Question 14

Verotoxin

Answer 14

• E.Coli 0157H7

~ can cause HUS -> microangiopathic anemia

Question 15

TTP/HUS lab findings

Answer 15

• thrombocytopenia (using up platelets)
• NORMAL PT/PTT
• anemia schistocytes
• increase MGKs on biopsy

Question 16

• Genetic GP1a deficiency

- mild tcytopenia and enlarged platelets

Answer 16

• Bernard-Soulier syndrome

-

Question 17

• GPIIb/IIIa defect; impaired platelet aggregation

Answer 17

Glanzmann Thrombasthenia

Question 18

TTP

Answer 18

• ADAMSTS13 deficiency
• vWF doesn’t get broken down -> microangiopathic hemolytic anemia (schistocytes)
• usually auto-antibody: adult females
• CNS effects predominate (over renal as in HUS)

Question 19

HUS

Answer 19

• classically seen in EHEC 0157:H7
• skin and mucosal bleeds, Microangiopathic HemeAneme
• renal insufficiency
• Tcyt, with increased bleeding time, normal PTT/PT, schistocytes,

Question 20

Secondary hemostasis

Answer 20

• after fibrinogen binds GPIIb/IIIa to form soft clot -> intrinsic cascade is activated to thrombin -> crosslinks in into hard clot

Question 21

Disorders of secondary hemostasis signs

Answer 21

• hemarthrosis, rebleeding, muscle bleeding

- measured by PT/PTT

Question 22

Hemophilia A

Answer 22

• factor VIII deficiency
• X linked or de novo
• increased PTT
• normal PT
• decreased factor VIII
• normal platelet count and bleeding time

Question 23

Hemophilia B

Answer 23

• same as A but with factor IX

Question 24

Factor inhibitor

Answer 24

- test with mixing study: factor deficiency will correct, inhibitor will not

Question 25

Newborns, long-term antibiotic therapy, malabsorption | - Liver failure can mimic due to the lack of production of epoxide reductase

Answer 25

Vitamin K deficiency

Question 26

Newborns, long-term antibiotic therapy, malabsorption | - Liver failure can mimic due to the lack of production of epoxide reductase

Answer 26

- Vitamin K deficiency

Question 27

Heparin-induced thrombocytopenia

Answer 27

- Platelet destruction secondary to heparin therapy may cause thrombosis

Question 28

Common causes of DIC

Answer 28

- Amniotic fluid - Sepsis traditionally E. coli or N. meningitis (TNF IL1) - Adenocarcinoma mucin activating coagulation - Acute promyelocytic leukemia, MPO - Rattlesnake bite

Question 29

DIC lab findings

Answer 29

- Decreased platelet counts - Increased PT/PTT (Getting used up in clots) - decreased fibrinogen (Getting used up in clots) - Microangiopathic hemolytic anemia - Elevated D dimer most specific for DIC (Split product of cross-linked fibrin)

Question 30

- Resembles DIC but with negative D dimer And normal platelets - Due to plasmin overactivity ~ Radical prostatectomy ~ Liver Cirrhosis

Answer 30

Disorder of fibrinolysis

Question 31

Virchow Triad

Answer 31

- Endothelial damage, venous stasis, hypercoagulability

Question 32

Lines of Zahn

Answer 32

- Along with adherence to endothelial wall indicates premortem clock

Question 33

Heparin like molecules

Answer 33

Activates anti-thrombin three -> Activates protein C which sequesters factors V and VIII

Question 34

Endothelial protection against thrombus

Answer 34

- Block exposure to sub endothelial collagen - Prostacyclin and nitrous oxide vasodilation - Heparin like molecule secretion - TPA secretion - Thrombomodulin secretion (modulates thrombin -> activate protein C)

Question 35

Elevated homocystine

Answer 35

- Due to folate or B12 deficiency | - Results in endothelial damage -> Increasing risk for thrombus

Question 36

Considerations in pre-existing protein C or S deficiency

Answer 36

- Administration of warfarin can lead to skin the necrosis, in addition to the increased risk for thrombus

Question 37

Most common inherited hypercoagulable state

Answer 37

Factor five leiden mutation | - Lacks binding site for deactivation by protein CNS

Question 38

No increase in PTT with standard heparin dosing

Answer 38

Anti-thrombin III deficiency

Question 39

- Shortness of breath, hemoptysis, chest pain - VQ mismatch - Positive D dimer

Answer 39

- Diagnostic for pulmonary embolism - Typically from right ventricle - Sudden-death from saddle embolus

Question 40

Extrinsic factor production

Answer 40

- hepatic | - liver damage -> prolonged PT