Coagulation Factors

Question 1

What factor is associated w/ the extrinsic pathway?

Answer 1

Factor 7

Question 2

What are your enzymatic factors? Non enzymatic

Answer 2

Xa,XIa,XIIa, IXa, VIIa, I,IIa, II (prothrombin),
• III(tissue factor, factor III, thromboplastin), Va, VIIIa, calcium
(factor IV, platelets

Question 3

what are you vit K dependent cofactors?

Answer 3

2, 7, 9, 10 (they are neg. charged)

Question 4

what is needed for efficient coagulation?

Answer 4

Ca2+, platelet membrane, and factor V.

Question 5

What activates the hemostastis cascade?

Answer 5

Tissue factor activates the 2ndary hemostasis cascade

Question 6

what acts on plasminogen to create plasmin?

Answer 6

Tissue plasminogen activator.

Question 7

When can you see a significant increase in fibrinogen concentration? decrease?

Answer 7

Inflammation, increase in dehydration.
• Decrease! consumption due to hypercoagluation, decrease
production by liver.

Question 8

what does antithrombin act on?

Answer 8

Xa, Thrombin, IXa “ inhibits the conversion of prothrombin to
thrombin, inhibits conversion of fibrinogen to fibrin by thrombin

Question 9

What does thrombin feed back on

Answer 9

IX, VII, VIIIA, Va,

Question 10

How are antithromin and heparin relate?

Answer 10

Heparin binds to antithrombin causing a conformational change and exposes the thrombin binding site. Thrombin binds to antithrombin and heparin floats away. The thrombin antithrombin complex is cleared by the phagocytic system.

Question 11

expression of which cofactor initiates coagulation?

Answer 11

tissue factor III

Question 12

which factor drives amplification? and which 4 does it affect?

Answer 12

thrombin promotes amplification of 2ndary hemostasis and it acts on factor VII, factor XI, factor VIIIA, and factor Va.

Question 13

what are the four vitamin K dependent factors?

Answer 13

II, VII, IX, X (2,7,9,10)

Question 14

what 3 components contribute to coagulation efficiency?

Answer 14

Platelet membrane, Ca2+ and factor V

Question 15

what cofactor required for antithrombin to inactivate thrombin?

Answer 15

heparin

Question 16

what are 2 major end producs of fibrinolysis?

Answer 16

FDPs and D Dimers

Question 17

To collect a sample of blood for coag test- what tube do you put blood into?

Answer 17

avoid collection w/ a heparinized catheter, and place in sodium
citrate tube.

Question 18

What is aPTT and ACT (test the intrinsic pathway)?

Answer 18

to clot formation. if prolonged” deficiency or inhibition of any intrinsic or common pathway factor, or heparin therapy “ citrated plasma + contact activator + Ca2+ + PLT phospholipid substitute- requires 70% deficiency of factor before prolongation is detected!! more sensitive that ACT
• ACT- activate clotting time- measures time for fibrin clot formation in non anticoagulated whole blood + contact activator. requires 95% deficiency of factor before prolongation is detect

Question 19

what is PT? (extrinsic pathway)

Answer 19

prothrombin time, measures time for fibrin clot formation in
citrated plasma + tissue factor + Ca2+ PLT phospholipid substitute:
o sig. of prolonged time= factor VII deficiency (good screen test for vitK b/c shorted 1⁄2 life of all factors) and also
deficiency /inhibition of common pathway factor. requires 70% deficiency of factor before prolongation

Question 20

what is TT test?

Answer 20

Thrombin time- measures time for fibrin clot formation in citrated
plasma + thrombin
• significance if prolonged- abnormality of fibrinogen;
inhibitors of fibrin formation (heparin, FDPS)
o fibrinogen decrease w/ consumption due to hypercoagulation (excessive conversion of fibrinogen to fibrin) or w/ decreased production by the liver

Question 21

what are PIVKA proteins?

Answer 21

proteins induced by vitamin K antagonism- increased in vit K

antagonism/deficiency

Question 22

what can an increase in FDPs demonstrate?

Answer 22

(w/ fibrinogen and soluble fibrin) increased fibrinolysis, severe
internal hemorrhage w/ fibrinolysis, and decreased clearance of
FDPs by liver.

Question 23

when FDPs are pathologically increased, what do they do to platelet function?

Answer 23

inhibit platelet function and fibrin polymerization (not when normal though)

Question 24

what causes increase in D-Dimers?

Answer 24

degredation of crosslink fibrin; increase fibrinolysis, severe internal
hemorrhage w/ fibrinolysis, decreased clearance of FDP by liver

Question 25

how does citrated plasma differ from blood?

Answer 25

No RBC, WBC, platelets. Decreased calcium (chelated by citrate

Question 26

what can happen to antithrombin in hypercoaguable state?

Answer 26

decreased in consumption- as with DIC and pulmonary thromboembolism or w/ loss- PLE, PLN.
• remember w/out Antithrombin III heparin is useless in its action (heparin activates antithrimbin III resulting in inhibition of thrombin and activated coagulation factors IXa, Xa, Xia, and XIIa in liver

Question 27

what are the patterns of hemorrhage?

Answer 27

major hemorrhages often in multiple sites- SQ, IM hematomas, large areas of echymosis.;
• bleeding into cavities(thorax and abdomen), joints blood in stool, vomit, urine.

Question 28

major cause of Vitamin K deficiency? clinical signs?

Answer 28

warfarin toxicity- inhibits vitamin K epoxide reductase- reduction in
factors II, VII, IX, and X.
• anemia, weakness, pallor, hypovolemia, shock, dyspnea, lameness,
neuro signs- signs often from bleeding into respective cavities,
death.

Question 29

what are lab findings w/ warfarin toxicosis?

Answer 29

regenerative anemia, variable leukogram PLT count normal (not platelet issue), prolonged PT, apt, ACT (why- b/c II, VII, IX, and X are involved in both pathways) PIVKA positive .

Question 30

What is DIC? causes

Answer 30

syndrome from continued activation of coagulation and fibrinolysis-
results in thrombosis of microvasculature, depletion of coagulation
factors and PLTS leading to bleeding.
• causes- induction or exposure of tissue factor or other activators of
of coagulation” sepsis, tissue necrosis, neoplasia; endothelial damage exposing collagen’ proteolytic enzymes (snake venom, trypsin released during pancreatitis); stagnant blood flow

Question 31

what are the 2 phases of DIC?

Answer 31

Hypercoaguable state (phase 1)- thrombosis and ischemic necrosis
and organ dysfunction
• Consumptive phase (phase 2)- consumption of PLT, coag factors
and Antithrombin III leading to bleeding.
o increased fibrinolysis w/ increased bleeding.

Question 32

what are lab changes seen in DIC?

Answer 32

consumptive phase- thrombocytopenia (mild/moderate), prolonged
PT, aPTT, decreased fibrinogen concentration, increased FDP and D dimers, decreased Antithrombin, hemorrhagic anemia, schistocytes (from fibrin formation)

Question 33

what must you do prior to the biopsy of the liver?

Answer 33

check for coagulation abnormalities (you are performing the biopsy b/c you know something is wrong with the liver- liver produces coag factors – in failure- decrease coag factors.