18: Anticoagulant toxicity Flashcards

1
Q

what is the INR target for mechanical heart valves, aFib and VTE

A

mech valves = 2.0-3.5
AFIB and BTE - 2.0-3.0

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2
Q

what is defined as minor bleeding

A

trivial bleed that resolves within 20 minutes

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3
Q

what is defined as a major bleed

A

bleeding into critical organ or a decline in HgB 20g/L (requires transfusions (1 pack of blood ~10g/L)

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4
Q

CBCs should be done _________ for those on anticoagulants

A

yearly

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5
Q

which is more easily treated? bleeds or clots

A

bleeds

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6
Q

what is the most feared bleeding complication

A

intracranial bleed

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7
Q

which 2 types of intracranial bleed is typically due to trauma in the elderly but prognosis is typically good

A

epidural or subdural hematoma

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8
Q

which of the following has worse prognosis
1. epidural hematoma
2. subdural hemoatoma
3. subarachnoid hemorrhage
4. intracerebral hemorrhage
5. 1+2
6. 3+4

A

6

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9
Q

why are intracranial hemorrhages so dangerous

A

Fixed space (within skull), concern with initial volume and expansion of bleeding

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10
Q

hemorrhages on anticoagulants have higher (3)

initial______
risk of _____
severity/ probability of ____

A

initial volume
risk of expansion
severity/ probability of death

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11
Q

DOACs reduce risk of aaICH by ________ compared to warfarin

A

30-70%

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12
Q

compared to warfarin, DOAC ICHs have (3)

______ volumes of blood
less severe ______/ more functional recovery
fewer ____s

A

smaller volumes of blood
less severe strokes/ more functional recovery
fewer deaths

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13
Q

what is the msot common extracranial bleed

A

GI

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14
Q

in extracranial major bleeding from ACs
1. majority result in full recovery spontaneously
2. requires reversal or interruption of treatment
3. the most common area is the lungs (pneumothorax)
4. none of the above is true

A

2

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15
Q

DOACs ___________ compared to warfarin
1. decreases both ICH and GI bleeds
2. increases ICH and decreases GI bleed
3. decreases ICH and increases GI bleed
4. increases ICH and GI bleeds

A

3 (but increase in GI bleeds is not stat sig)

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16
Q

T or F: high bleed risk score is not a reason to avoid anticoagulants

A

T

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17
Q

in ____, thrombotic and bleed rsk often rise in parallel

A

AF

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18
Q

what 6 things must you do for assessment of bleed

A

location
timing of blood loss
quantify and qualify blood loss
immediate mnagement
future management
impact of major bleed vs clotting event

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19
Q

generally, what is a good time to restart anticoagulation tx

____ usually
_ week if cause of bleed identified and rectified
_____ wks if conservative approach

A

2wks usually
1 week if cause of bleed identified and rectified
2-8 wks if conservative approach

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20
Q

observational data shows that restarting AC after GIB ____________________________

A

reduces risk of thrombosis and mortality and doesn’t increase risk of recurrence

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21
Q

observational data shows that restarting AC after ICH ___________________

A

decreases risk of ischemic events and mortality + no differences in major bleeding

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22
Q

critical INRs are defined as

A

INR >5.0

23
Q

WHO requires labs to perform quality assurance testing between INR ________

A

1.5-4.5 only

24
Q

what are 4 general categories of factors that elevate the INR

______ in health
changes to ________
changes to ______
administration of_________

A

deteriorations in health
changes to medications
changes to lifestyle
administration of too much warfarin

25
Q

what changes in lifestyle may affect INR

A

vit K intake
alcohol consumption
level of activity

26
Q

induction/ inhibition of this CYP enzyme causes major changes to INR ___________. minor changes occur with ___ and __________

A

2C9 = major
minor = 3A4, 1A2

27
Q

IV vit K admin for warfarin reversal is used in ___________ and takes affect in _____________

A

life threatening situations
6-12hrs

28
Q

oral vit K is used in ________ and takes effect in ______________

A

nonemergency situations
16-24hrs

29
Q

what 2 routes of vit K should be avoided

A

IM and SQ

30
Q

typical ER dose of IV vit K

A

10mg

31
Q

in a pt with INR 4.5-10.0 guidelines suggest

_______ routine use of vit K
- can you “consider” vitK?

A

against routine use of vit K
hold 1-2 warfarin doses and consider vit K PO 1-2.5mg and reassess INR

32
Q

in a pt with INR >10, guidelines suggest

A

hold warfarin
vit K PO 2-5mg and reassess INR

33
Q

PCC reverses INR within

A

minutes

34
Q

after a critical INR has been managed and the acute, reversible cause identified, what action should take place?

A

document INR <4
implement warfarin dosing similar to that prior to the cause occured

35
Q

after a critical INR has been managed and the acute, non reversible cause identified but will continue, what action should take place?

A

document INR <4
empirically decrease warfarin dosing based on experience/ literature

36
Q

after a critical INR has been managed and no identifiable reason has been found what action should take place?

A

document INR <4
depending on clot vs bleed risk, reduce maintenance dosing accordingly (typically ~10% decrease but individualize based on pt)

37
Q

PCC is derived from ______ and administered by _________

A

human plasma
IV infusion

38
Q

PCC contains factors ___________ and protein ____________

A

factors 2, 7, 9, 10
C, S

39
Q

PCC reduces INR within minutes but the effect is not sustained, _______ must also be administered to sustain reversal in INR

A

vit K (~10mg)

40
Q

PCC indications (2)

A

Serious or life threatening bleeding
Requires urgent (<6hrs) interventions with risk of bleeding

41
Q

aPPC contains _____________ and is mostly used in ___________

A

activated factor 2a (i think it’s atually 7a….)
hemophilia patients

42
Q

rank the DOACs based on renal elimination

A

dabig > edoxi > rivaroxi >apixa

43
Q

which DOAC can be removed by dialysis

A

dabigatran

44
Q

there may be an accumulation of DOACs if

A

overdose, acute renal failure, DDI (strong P-gp inhibitor for D and E, strong P-gp + 3A4 inhibition for R and A)

45
Q

when would DOAC reversal be needed

A

major bleeding or urgent need for procedure
acute ischemic stroke (and desire for thrombolysis- off label)

46
Q

antifibrinolytisc MOA

A

inhibit fibrinolysis by preventing conversion of plasminogen to plasmin, plasmin then can’t act on fibrin to clot

47
Q

T or F: antifibrinolytics are antidotes for DOACs and warfarin

A

F- doesn’t make clots, only blocks their break down

48
Q

what are 2 practiacl uses of antifibrinolytic agents

A

topical if dental/ nasal bleeding, oral if heavy menstruation or IV in operating room

49
Q

dabigatraan antidote is __________, which is a _____________ that binds ________ to dabigatrain with 350x stronger affinity than thrombin

A

idarucizumab
enginerred antibody fragment
noncompetitively to dabigaatran

50
Q

idarucizumaba is indicated for adult pts treated with dabigatran when

A

rapid reversal of anticoagulant effect is required for emergency surgery/ urgent procedures or life threatening or uncontrolled bleeding

51
Q

what is the antidote for factor Xa inhibitors

A

andexanet alfa

52
Q

andexanet alf is a _______________ that acts as _________ with high specificity for both oral and injectable Fxa inhibitors

A

modified recomb factor Xa
competitive decoy to target and sequester

53
Q

andexanet alfa is catalytically _____

A

inactive