Exam 3 Blood Stuff Flashcards
(101 cards)
1
Q
Most coagulation factors circulate in the body as inactive enzymatic precursors called
A
zymogens
2
Q
Catalyst transforming inactive into an active state
A
Proteases
3
Q
What does hemostasis essentially mean?
A
to stop bleeding
4
Q
name of factor I and source?
A
Fibrinogen
source: liver
5
Q
name of factor II and source?
A
Prothrombin
source: liver
6
Q
name of factor III and source?
A
Thromboplastin/Tissue Factor
source: platelets/endothelium
7
Q
name of factor IV
and source?
A
Calcium
soruce: Bone and GI
8
Q
name of Factor V and source?
A
Labile Factor/Proccelerin
sorce: liver/platelets
9
Q
name of Factor VII and source?
A
Porconvertin/SPCA
source: liver
10
Q
name of Factor VIII and source?
A
Anti-Hemophilic Factor A
source: endothelium
11
Q
name of Factor IX and source?
A
Christmas factor
source: liver
12
Q
name of Factor X and source?
A
Stuart factor
source: liver
13
Q
name of Factor XI and source?
A
Plasma Thromboplastin Antecedent (PTA)
source: liver
14
Q
name of Factor XII and source?
A
Hageman factor
source: liver
15
Q
name of Factor XIII and source?
A
Fibrin stabilizing factor
source: liver
16
Q
Factors that DO NOT come from the liver?
A
Factor 3, 4, 8, and vonW
17
Q
What factors are part of the Intrinsic Pathway?
A
Factor 12, 11, 9, (8)
18
Q
What factors are part of the Extrinsic pathway?
A
Primarily Factor 7 (but also 3)
19
Q
Common pathway factors?
A
Primarily 10
but also 5,2,1, and 13
20
Q
PT tests which pathway?
A
Extrinsic
21
Q
APTT tests which pathway?
A
Intrinsic
22
Q
Cryoprecipitate is rich in what factors?
A
Fibrinogen
factor VIII
factor XIII
von WF
23
Q
1 unit of cryo per 10kg body weight increases plasma fibrinogen by how much?
A
roughly 50-70mg/dL
24
Q
Is cryo used to treat DIC, why or why not?
A
should not be used to treat DIC because it lacks factor V
25
What all is plasma/FFP used for? (4)
Replace volume and coagulation factors during massive transfusions.
To treat or prevent future bleeding during surgery and invasive procedures.
To reverse warfarin therapy.
Treatment of coagulation factor abnormalities where specific concentrates are not available.
26
How long can Plasma/FFP be stored for?
1 year
27
What degree are platelets stored at?
22 C
leaving them at risk for potential bacterial growth.
testing of all platelet products is mandated.
28
Most blood products are stored at what degree, other than?
most are stored at 4 C, except for platelets which are stored at 22 C
29
Apheresis platelets, how do they differ from normal platelets?
sufficient enough number of platelets can be collected from a single donor when apheresis is used (compared to 10 donors)
30
TXA: loading dose
1 g over 10 minutes then 1 g over 8 hours.
31
What is heparin rebound?
heparin rebound can occur after initial reversal and is generally observed 2-3 hours after first dose of protamine when pt. is in the ICU.
32
How much protamine is needed to antagonize 100 units of heparin?
1 mg protamine for every 100U of circulating heparin
33
Protamine adverse reactions include?
anaphylaxis
acute pulmonary vasocostriction
RV failure
Hypotension
34
What patient is at the most "increased risk" for adverse reaction to protamine?
diabetics who use NPH which contains insulin and protamine.
35
What four groups of people are at risk for protamine reactions?
diabetics who use NPH
men with vasectomies
people with multiple drug allergies
prior protamine exposure
36
DDAVP, what type of VWD does it treat and which ones does it not treat?
used to treat VWD type 1
not effective for severe forms of VWD types 2 and 3.
37
only agent that reverses heparin (not LMWH)
Protamine sulfate
38
excessive protamine use can cause what?
prolongs ACT and causes platelet dysfunction
39
PCC (prothrombin complex concentrates) are concentrations of coagulation factors that include factors?
```
II
VII
IX
X
(1972)
```
40
When are PCCs recommended in guidelines as primary treatment?
as a reversal in pts with life- threatening bleeding with increased INR when urgent reversal is required.
41
what is typically used in the united states to reverse too much Warfarin?
FFP
| most other countries use PCC
42
Compared with FFP, PCCs provide?
quicker INR correction
have a lower infusion volume
and are more readily available without crossmatching
43
Fibrinogen normal levels?
| also normal in pregnancy
200-400 mg/dL (elevated to >400 mg/dL in pregnancy)
44
What can replinish fibrinogen? (what blood product)
cryoprecipitate
1 unit of cryo per 10 kg increases fibrinogen by 50-70 mg/dL
45
What 2 human thrombins are available for clinical use?
Recombinant human thrombin (RECOTHROM)
Factor VIIa -Useful in battle field trauma
46
what is normal aPTT in sec. ?
30-35
47
What must Heparin bind to in order to act as an anticoagulant?
antithrombin (AT)
48
What lab do you typically use in the OR to monitor Heparin?
ACT
| reliable for high heparin concentrations > 1.0 unit/mL
49
what is the ACT time you want for a CABG?
greater than 350 (350-400)
50
Is Heparin an acid or a base?
acid
51
Is protamine an acid or a base?
base
52
how long before surgery do you need to stop LMWH?
12 hours (longer with renal dysfunction)
53
How long before surgery do you need to stop Arixtra?
2 days
54
What is aPTT?
Activated Partial Thromboplastin Time (aPTT):
Used to monitor heparin and maintain a ration of 1.5 to 2.5 times normal values for aPTT (normal 30-35 seconds).
55
Aprotinin Therapy: Is it recommended to use kaolin-ACT or celite-ACT, why?
Use Kaolin-ACT as it binds to aprotinin to minimize it's effect
56
ACT may be influenced by? (4)
Hypothermia
Thrombocytopenia
Presence of contact activation inhibitors (aprotinin)
Preexisting coagulation deficiencies (fibrinogen, factor XII, factor VII)
57
For cardiac surgery, a baseline ACT is determined at what times (3)?
before IV administration of heparin
3-minutes after administration
at 30 minute intervals thereafter
58
How long before normal surgeries should you stop heparin? (not GABG)
4-6 hours
59
What is normal ACT clotting time?
100-150 seconds
60
onset of action of IV heparin and SC heparin?
IV is immediate
| SC is 1-2 hours
61
half time of heparin?
approx. 1 hour
62
What is unique about xarelto?
does not require AT as a cof-actor.
63
if you have a neuraxial catheter in place how long do you have to wait to remove it after last xarelto dose?
18 hours
64
if a neuraxial catheter has been removed how long do you have to wait before you give the next dose of xarelto?
6 hours
65
When do you stop warfarin before an elective procedure?
5 days typically.
you want INR less than 1.5.
patients may require bridging with heparin.
66
when do you stop xarelto before elective surgery?
24 hours, but if renal dysfunction then around 48 hours (prolonged)
67
Tell me about protamine / heparin binding?
o Protamine is positively charged alkaline that combines with the negatively charged acidic heparin to form a stable complex that is devoid of anticoagulant activity.
68
Does protamine neutralize LMWH?
NO!
69
What surgery populations have higher risk of DVT?
o ORTHOPEDIC
o THORACIC
o CARDIAC
o VASCULAR
70
What two anticoagulants can you give to renal patients due to minimal renal clearance?
Heparin and Warfarin
71
After stopping Argatroban when does anticoagulation return to baseline?
4 hours
72
Two synthetic direct thrombin inhibitors (first isolated from leeches)?
Lepirudin
| Desirudin
73
What is argatroban used for?
prophylaxis or treatment of thrombosis in patients with or at risk for HIT undergoing PCI
74
antagonist of Warfarin?
Vitamin K
75
How does Warfarin work (MOA)?
Inhibits vitamin K epoxide reductase that converts the vitamin K-dependent coagulation proteins (Factors II, VII, IX and X) into active forms
76
How long does it take warfarin to start working?
8-12 hours
77
When do peak effects of Warfarin occur?
| Peak CONCENTRATION occurs when?
effect: 36-72 hours
concentration: 1 hour
78
What is warfarin bound to and percentage bound?
97% bound to albumin: Thus long elimination half time of 24-36 hours and very little renal excretion.
79
What do you want someones INR to be if they are on warfarin?
2-3 x normal value.
80
what is the elimination half time for warfarin?
24-36 hours
81
Does warfarin cross the placenta?
yes with exaggerated effects on the fetus
82
direct factor Xa inhibitor with greater than 10,000 fold selectivity for Xa than other related serine protease describes what medication?
Xerelto
83
Other name for xerelto?
Rivaroxaban
84
How often do you administer Apixaban?
Administered BID
85
What all is Apixaban (eliquis) used for?
Approved for reduction of risk of stroke and systemic embolism in nonvalvular atrial fibrillation, prophylaxis of DVT following hip or knee surgery, Tx and Reduction of DVT and PE
86
How long do you wait after catheter removal to give first dose of Dabigatran (Pradaxa)?
first dose 2 hours after catheter is removed.
87
how long before surgery do you stop taking aspirin?
7-10 days before surgery
88
When can you resume ASA use?
24 hours post op after hemostasis has taken place (not sooner)
89
What does ASA do to the platelets?
causes plts to not stick to one another and affect is irreversible and lasts for the life of the platelet (7-10 days)
90
ReoPro:
when do you stop preop?
elimination half life?
stop: 72 hours preop
| 1/2 life: 12-24 hours
91
Name two prodrugs (anticoagulants)
Clodidogrel (plavis)
| Prasugrel (effient)
92
Aggrastat and Integrelin
| when to stop before surgery and elimination half life?
stop 24 hours preop and 1/2 life is 2-4 hours
93
what does lupus anticoagulant cause?
antiphospholipid syndrome, which is a phospholipid binding antibody.
these patients may present with prolonged PT and PTT but they are actually hypercoagulable.
94
What is TRALI?
Acute lung injury occuring within 6 hours of the end of plasma containing blood transfusion.
hypoxia with noncardiogenic pulmonary edema.
95
What has been done to decrease the incidence of TRALI?
plasma only from men, or women who have not had children (screening female donors)
96
potential complication of TXA? (high dose)
seizures
97
warfarin is a vitamin K antagonist, helping the blood stay thin. If you need to urgently (emergent) reverse Warfarin then you can use?
if emergent most US doctors will use FFP but outside of the US (if bleeding and elevated INR) use PCC.
Vit. K injection is not for emergent use.
98
list some serine proteases? (anticoagulants, if you catalyze proteins you change their function, speed them up)
antithrombin (AT)
thrombine
protein C
protein S
99
What factor plays a major role in the terminal phase of the clotting cascade and promotes formation of cross linked fibrin polymers and generation of a stable hemostatic plug?
factor XIII
100
What factor exists as a tetrameric precursor (zymogen) of 2A and 2B subunits and is converted into an active transglutaminase by thrombin and calcium?
factor XIII
101
what test checks the clotting of warfarin? Heparin?
```
Warfarin = PT
Heparin = PTT
```
