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Board Review CRNA (Sweat Book) > Hemostasis > Flashcards

Flashcards in Hemostasis Deck (104)
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1

What are the 4 stages of hemostasis?

I: Primary
II: Secondary
III: Anticoagulation
IV: Fibrinolysis

2

What are the 4 main stages of primary hemostasis?

1) adhesion
2) activation
3) aggregation
4) fibrin

3

______ promotes platelet ADHESION.

von Willebrand factor (vIII)

4

Where is vWF manufactured and released from?

endothelial cells

5

vWF is the ligand for the _______ receptor found on the platelet.

GP1b

6

What is the life span of a PLT?

8-12 days

7

What is the normal value for PLT's?

150,000-400,000 cells per mL

8

What percent of the PLT's can be found sequestered in the spleen?

33%

9

What is the MOST common inherited coagulation defect?

vWF disease (vIII)
*the more common form is characterized by insufficient production of vWF by endothelial cells

10

Why should you still suspect vWF disease in a pt with a normal PLT count and increased bleeding time?

they may have enough platelets, but it is the vWF that adheres the PLT to the injury site

11

What is the 1st line treatment for vWF disease? How does it work?

D-amino D-arginine vasopressin (DDAVP, desmopressin)--> a non pressor analogue of arginine vasopressin causes release of endogenous stores of vWF
effective in 80% of cases

12

What is the dosing for DDAVP for vWF?

0.3mcg/kg IV infusion for 10-20 minutes
PLT adhesion is increased within 30 minutes of injection and wears off at 4-6 hours

13

What is the concern with DDAVP administration in vWF disease type 2B?

thrombocytopenia

14

What is given to patients that do not respond to desmopressin for vWF disease?

cryoprecipitate or factor VIII concentrate (Humate-P)

15

What factors does cryoprecipitate have?

factor VIII, I (fibrinogen), XIII

16

What is needed to activate the PLT?

thrombin (activated factor II or IIa)

17

What is synthesized and released from the activated PLT?

thromboxane A2 and ADP

18

What is the role of thromboxane and ADP?

uncovers fibrinogen receptors on the platelet by conformational change---> it binds to the receptor activating signal transduction---> fibrinogen then attaches thereby linking other PLT's to each other

19

What is formed during aggregation?

platelet plug

20

How strong is a PLT plug?

water soluble and friable

also called a white thrombus or white clot

21

_______ aggregates platelets.

fibrinogen (factor I)

22

What occurs in the PLT after the thrombin attaches?

it is activated--> phospholipase A2 liberates arachidonic acid--> cyclooxygenase converts arachidonic acid to prostaglandin G2--> PGG2 is metabolized to PGH2--> PGH2 is converted to a variety of prostaglandins and thromboxane A2

This is the arachidonic acid cascade.

23

Name the arachidonic acid cascade.

phospholipase A2 liberates arachidonic acid--> cyclooxygenase converts arachidonic acid to prostaglandin G2--> PGG2 is metabolized to PGH2--> PGH2 is converted to a variety of prostaglandins and thromboxane A2

24

What part of hemostasis does drugs like aspirin, NSAIDs, and Plavix effect?

platelet aggregation

25

What is the fibrinogen receptor?

GPIIb/IIIa

26

Name common anti-fibrinogen receptor drugs.

Eptifibatide (integrilin)
Abciximab (Reopro)
Tirofiban (Aggrastat)

Remember "EAT"

27

How many hours before surgery should the following drugs be discontinued?
Eptifibatide (integrilin)
Abciximab (Reopro)
Tirofiban (Aggrastat)

Eptifibatide (integrilin)--> 24 hours
Abciximab (Reopro)--> 72 hours
Tirofiban (Aggrastat)--> 24 hours

28

How many hours before surgery should the following drugs be discontinued?
Aspirin
NSAIDs

Aspirin: 7-10 days (life of PLT)
NSAID: 24-48 hours

29

How do the following drugs work?
Eptifibatide (integrilin)
Abciximab (Reopro)
Tirofiban (Aggrastat)

They cap the fibrinogen receptor to prevent attachment of fibrinogen--> so no aggregation

30

Name 2 anti ADP drugs.

Clopidogrel (Plavix)--> anti ADP agent (life of PLT)
Ticlopidine (Ticlid)--> inhibits ADP induced fibrinogen aggregation