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Flashcards in Hemostasis 2 Deck (17):
1

common pathway steps

activated X (plus Va and PL and Ca) activate prothrombin to thrombin aka 2a. convert fibrinogen to fibrin (1a) and you get a crosslinked stable fibrin clot

2

lab evaluation of common pathway

PT and PTT in conjunction

3

thrombin: functions

converts fibrinogen to fibrin. activates factor 13 for stabilizing/crosslinking fibrin clot. activates factor 11, 8 (intrinsic) and 5 (common). activates platelets directly

4

what does PTT assess

intrinsic pathway: 12, 11, 9 and 8

5

PT assess?

extrinsic pathway: factor 7

6

PTT and PT both assess

the common pathway: 10 5 2 and 1

7

PT: what do you put in the test tube?

patient plasma, Ca and PL and tissue factor = forces it to the extrinsic pathway

8

PTT: what do you put in the tube

patient plasma, Ca, PL and negatively charged surface activator which activates XII = intrinsic pathway

9

INR

PT (extrinsic) converted to a ratio aka international normalization ratio

10

fibrinolysis

normal process that melts clots aa breaks down or lyses the clot

11

fibrinolysis: main steps

plasminogen converted into plasmin, breaks fibrin down into degradation products including D dimers

12

fibrinolysis and PT/PTT?

not reflected by PT/INR or PTT: only measures how long it takes for clot to form

13

so how would you measure fibrinolysis

fibrinogen. d dimers. other special tests

14

categories of bleeding disorders (3)

platelet disorders. von willebrand diasease. (these two are primary hemostatic disorders. factor deficiencies (secondary hemostatic disorder, aka coagulation factor problem)

15

causes of acquired bleeding disorders (9)

drugs/medications. alcohol. liver/kidney failure. cardiopulmonary bypass. marrow failure/hematologic disorders. acidosis/hypothermia/hypocalcemia. disseminated intravascular coagulopathy DIC. hyperfibrinolysis. vascular/collagen disorders.

16

effects of primary vs. secondary hemostatic defects

primary (VW disease, platelet dysfunction) = muco cutaneous bleeding like nosebleeds, heavy periods, bleeding into skin. secondary (hemophilia) = deep tissue hematomas, bleeding into joints and muscles

17

4 examples of cutaneous bleeding

petechia, purpura, ecchymosis, hematoma