Coagulation Flashcards
1
Q
What are BVs made of
A
epithelial cells
2
Q
First step after BV is injured
A
Platelets circulate in the body and go to fill the injury
3
Q
Fibrin
A
strands that join together at the injury and seal the plug
4
Q
Fibrinogen
A
covers the active part of fibrin until converted at the site of injury so the fibrin does not clot in the blood
5
Q
What causes fibrinogen to turn into fibrin
A
proteins in the blood—thrombin
6
Q
thrombin
A
active form that helps convert fibrinogen into fibrin; helps make plasmin from plasminogen; breaks up fibrin to prevent constant clotting
7
Q
tissue factor
A
Joins with VII to make factor X
7
Q
prothrombin
A
inactive form of thrombin
8
Q
How is the extrinsic pathway activated?
A
by initial BV insult
9
Q
intrinsic pathway
A
workhorse that gets most of the cascade done
10
Q
What is blood?
A
mostly plasma–water, also proteins and solutes
11
Q
plasma proteins
A
most is albumin and globulins, clotting factors, electrolytes
12
Q
albumin
A
control water/solutes in BVs vs cellular space
13
Q
globulins
A
HDLs, prothrombin, hormone-transporting proteins
14
Q
Most plentiful clotting facto
A
fibrinogen
15
Q
Where are most clotting factors made?
A
liver
16
Q
Natural killer cells
A
WBCs, defense against tumors and viruses
17
Q
Serum
A
plasma w/o clotting factors
18
Q
Primary activator of cascade
A
Platelets
19
Q
Platelet function
A
hemostasis, coag, release clotting factors; normally circulate as smooth platelets–inactive until find damage
20
Q
Platelets
A
not true cells–contain cytoplasmic fragments that can release adhesive pros, coag, and growth factors when they sense a vessel injury
21
Q
Thrombocytopenia
A
low platelets–under 100k; high risk for bleeds
22
Q
Where are extra platelets stored?
A
spleen
23
Q
Steps of activation of clotting system
A
inc platelet adhesion at site of injury (active dendritic platelets), platelet degranulation (active platelets release prothrombotic molecules like ADP, ADP binds and induces agg as platelet-vasc wall and platelet-platelet adherence inc, activation of clotting system
24
Thromboxone
helps recruit platelets to the site
25
blood clot
meshwork of fibrin strands and platelets; plug damage and stop bleeding--hemostasis
26
hemostasis
stopped bleeding
27
Which pathway is thrombin more active in?
Intrinsic
28
Target of clot medication
thrombin
29
How does body know to stop the clot?
anti-thrombin 3 is a circulating thrombin inhibitor, tissue factor pathway inhibitor inhibits factor Xa after body is clotted
30
fibrinolysis
natural removal of clot; b/d of fibrin; tissue plasminogen activator turns plasminogen into plasmin which b/d fibrin and releases the caught blood cells, breaking the mesh up into fibrin degradation products
31
u-PA
Also tells plasminogen to activate plasmin and break up fibrin
32
Clot risk factors
DVT, immobility, afib, heart attack, heart failure, stroke history
33
coag goals
prevent clot formation, break apart existing clot, help inc circ and perfusion, dec pain, prevent further tissue damage
34
heparins and coags biggest concern and NC
bleeding--ext or int; monitor Hgb and HCT, need to know where your pt is at risk of bleeding from and why they are on an anti-coag, VS change
35
sx of bleeding
tachy (first sign), dec BP, resp chx, bruising; bright blood after surgery
36
antithrombotics
prevent clot/thrombus
37
anticoags
prevent action of clotting factors and prevent clots
38
antiplatelets
prevent platelet plugs from forming by dec platelet agg; best for preventing heart attack and stroke
39
Heparin MOA
prevent clots by activating anti-thrombin which indirectly inactivates thrombin and factor Xa (and more clotting factors); inhibits fibrin formation
40
enoxaparin (low molecular weight heparin)
prevents clots by inactivating factor Xa; takes large Hep mol and cleaves them into smaller mol that adhere to Xa and become more bioavailable with larger half life
41
Giving Heparin
only IV or SQ; parenteral only; in 5000 unit injection 2-3x/day or as IV drip with bolus; wt based in kg ONLY
42
Heparin indications
acts very fast and effectively so for condx that need prompt activity (evolving stroke, big DVT, heart attack, adjunct for dialysis); low dose SQ injection for prophylaxis against post-op DVT, DIC
43
Protamine sulfate
Heparin and enoxaparin antidote that binds with Heparin and immediately stops it; give IV SLOWLY to avoid BP drop
44
Heparin is HIGH RISK
check with other RN before giving, rate change or bolus; check labs first
45
SE of Heparin
bleeding, hematoma, anemia, thrombocytopenia
46
Bleeding sx
VS, bruising, petechiae (red dots on skin), hematomas, black tarry stool
47
Heparin induced thrombocytopenia
sim to allergix rxn; low platelet count and inc dev of thrombi caused by antibody dev
48
What to do if suspect HIT
monitor platelet count, STOP platelet immediately if count gets below 100k, switch to non-hep anticoag
49
What is IV heparin dose based on?
Clotting times--anti-Xa or aPTT; drawn q6h, change rate based on response
50
How to draw Hep labs
pause for several minutes and flush with saline before drawing blood
50
Therapeutic dose for Heparin
When labs show that you don't need a bolus 2x in a row--found therapeutic dose and only need to draw labs in the morning prob
51
Enoxaparin indications
prophylaxis and tx
52
Enoxaparin NC
can be given at home--pre-dosed; only SQ; DON'T give with heparin or other anticoagulants except oral warfarin when treating PE or DVT; do not expel the air bubble: will remain in plunger to ensure whole dose is given; slower onset of action compared to heparin but LONGER half-life; rotate injection sites
53
Enoxaparin SE
bleeding, thrombocytopenia, HIT
54
Black box for enoxaparin
potential spinal hematoma if patient has epidural catheter
55
Warfarin (coumadin) MOA
Vitamin-K inhibitor; prevents the synthesis of four coagulation factors (VII, IX, X, prothrombin)
56
Warfarin indications
prevention VTE/DVT/PE, thrombotic events for patients with afib or heart valves, reduce recurrence of TIA or MI
57
Warfarin SE
bleeding, lethargy, muscle pain, purple toes
58
Giving warfarin
ONLY given PO, once a day, usually at 5PM; Onset not until 24 hours! Duration 2-5 days
59
Warfarin antidote
Vit K (IV); if doesn't work--fresh frozen plasma (FFP) or whole blood
60
Warfarin NC
NOT for preg or breastfeeding bc DVT risk; Monitor & TEACH for signs of bleeding, HOLD before surgeries, monitor prothrombin time/INR; monitor INR monthly when reach therapeutic; many drug intx; food intx, avoid alc; Wear medic alert bracelet, use soft bristle toothbrush, no electric toothbrush
61
INR with warfarin
international normalized ratio; normally 1ish, with warfarin we want 2-3.5
62
Warfarin food intx
avoid foods high in vit K--green leafy veg like lettuce, kale, cucumber, kiwi, cabbage, etc
63
Apixaban (Eliquis) and Rivaroxaban (Xarelto) MOA
direct inhibitor of factor Xa
64
Apixaban (Eliquis) and Rivaroxaban (Xarelto) indications
prevent strokes in patients with afib, post-op thrombo-prophylaxis, treat DVT & PE
65
Apixaban (Eliquis) and Rivaroxaban (Xarelto) SE
bleeding, hematoma, dizziness, rash, gastrointestinal distress, peripheral edema
66
Black box warnings for Apixaban and rivaroxaban
spinal hematomas if pt has epidural catheter, risk of thrombosis if drugs stop abruptly
67
apixaban and rivaroxaban NC
Drug intx, don't give with other coags, watch liver fxn, don't stop taking abruptly
68
apixaban and rivaroxaban inc effect of
CYP3A4 inhibitors (amiodarone, erythromycin, ketonazole, HIV meds, diltiazem, verapamil, grapefruit juice)
69
apixaban and rivaroxaban dec effect of
Decreased effects: phenytoin, carbamazepine, rifampin, and st. johns wort
69
apixaban and rivaroxaban antidote
andexxa (recombinant factor Xa, inactivated zhzo)
70
aspirin (as anti-platelet)
Blocks prostaglandin synthesis through the COX
enzyme pathways; also BLOCKS PLATELET AGGREGATION; prevent platelet clumping
71
aspirin indx
prevent/treat MI, prevent ischemic stroke
72
How can you take aspirin?
given PO; can chew baby aspirin for acute event if not EC
73
aspirin SE
GI N/V, drowsy, confused, bleeding
74
aspirin NC
Reye's sx, OTC but prescribed by dr for platelet fxn, don't crush EC
75
aspirin CI
thrombocytopenia, active bleeding, blood cancers, traumatic injuries, GI ulcers, vitamin K deficiency, recent hemorrhagic stroke
76
DDAVP (desmopressin)
Antiplatelets antiode—clop, tica, aspirin
77
clopidogrel (Plavix) and Ticagrelor (Brilinta) MOA
Antiplatelet ADP inhibitor; alters the platelet membrane so it doesn’t receive the signal to
aggregate
78
Clopidogrel and ticagrelor indx
dec risk of stroke, prophylaxis of TIAs, post-MI
79
Clopidogrel and ticagrelor CI
thrombocytopenia, active bleeding, blood
cancers, traumatic injuries, GI ulcers, vitamin K deficiency,
recent hemorrhagic stroke
80
Clopidogrel and ticagrelor SE
chest pain, edema, flu-like symptoms, abdominal pain, diarrhea, nausea, epistaxis, rash, pruritus
81
Clopidogrel black box warning
patients with certain genetic abnormalities, who may have higher rate of CV events due to reduced conversion to its active metabolite
82
epistaxis
nose bleed
83
What dec clopidogrel's effectiveness?
amiodoarone, calcium channel blocker, NSAIDs, PPIs
84
Ticagelor black box warning
inc bleeding risk with aspirin dose over 100mg
85
Ticagelor antidote
DDAVP or platelet transfusion
86
Argatroban/bivalrudin class MOA and indications
Thrombin (factor IIa) inhibitors; treat HIT, for pt undergoing PCI procedures and at high risk for HIT
87
Thrombin inhibitors SE and NC
SE—bleeding; IV only, nursing implications—labs (anti-Xa, H&H, platelets), Argatroban—careful in pt with hepatic dysfunction
