Anticoagulation Flashcards
CHADS2-VASC calculation
C - congestive heart failure/ LV EF < 40%
H - hypertension
A - age >75 (2)
D - diabetes
S - stroke, TIA (2)
V - vascular disease (MI, PAD, aortic plaque)
A - age >65 - 74
S - sex (female gets a point)
HAS Bled Score
H - hypertension >160mmHg
A - abnormal renal/liver (1 pt each) (scr >2.2)
S - stroke
B - bleeding hx (anemia, bleeding disorder, prior bleed)
L - labile INR (time in range <60%)
E - elderly >65 years old
D - drug or alcohol excess (1 pt each)
What disease state do we use CHADS2-VASC and HAS-BLED?
Non valvular A fib
CHADS2 Score and treatment options
Men 0 / Female 1 - ASA or nothing
Men 1 / Female 2 - ASA or DOAC or nothing
Men >2 / Female 3 - DOAC
HAS BLED Score to worry about bleeding with Afib DOAC treatment
> =3
try to reduce risk factors if you can
Warfarin goal time in range
> 65%
duration of needed anticoagulation before cardioversion of Afib
3 weeks
duration to anticoagulated after cardio version of afib
4 weeks
more potent isomer of warfarin
S is 5 x more potent
indication to start lower dosing of warfarin initially
> age
low body weight
liver / heart / thyroid disorder
low albumin
warfarin drug interactions
decreased absorption - cholestyramine and sucralfate
CYP2C9 hits S enantiomor harder than 3A4
fevers eat up clotting factors faster
OTC - garlic and ASA
reduce INR - phenytoin, phenobarbital, carbamazepine, rifampin, St John’s wort
reduced clearance - flagyl, bactrim, fluconazole, isoniazid, fluoxetine, sertraline, amiodarone
Dabigatran Dosing
Afib - 150mg BID
Total Hip - dabigatran 110mg BID, then 220 daily
VTE - 5 days injection then 150mg BID
Rivaroxaban Dosing
Afib - 20mg PM
Total Hip/Knee - 10mg daily (don’t need food)
VTE: 15mg BID x 21 days, then 20mg PM, cut to 10mg after 6 mo.
Dabigatran renal dosing cutoff
Afib: CrCl <30 use 75mg BID, CrCl <15 do not use
VTE: CrCl <30 do not use
Rivaroxaban renal dosing cutoff
Afib - CrCl <50 - 15mg PM
VTE: avoid if CrCl <15
Apixaban Dosing
Afib - 5mg BID
Total Hip/Knee - apixaban 2.5mg BID (Hip x 35, Knee x 12)
VTE: 10mg BID x 7 days, then 5mg BID, 2.5mg after 6 mo.
Apixaban renal dosing cutoff
Afib - 2.5mg BID if >80yo, <60kg, sCr >1.5
VTE: avoid if CrCl <15, sCr >2.5
Edoxaban Dosing
Afib - 60mg daily
VTE - 5 days injectable then 60mg daily
Edoxaban renal dosing cutoff
Afib - <50 - 30mg daily, avoid if CrCl >95
dialysis effects on DOACs
Do Not Use - edoxaban, dabigatran
Reduce Dose - apixaban, rivaroxaban
INR to start DOAC
rivaroxaban <3
edoxaban <2.5
apixaban and dabigatran <2
Afib + PCI anticoagulants of choice
DOAC and clopidogrel x 1 yr, then DOAC only
if high bleed risk may do 6 months or 3 months of plavix
bioprosthetic valve replacement - anticoagulant choice and duration
ASA - could do warfarin for 3 - 6 months - but should do ASA for life
transcatheter aortic valve replacement (TAVR) Less invasive
ASA only but could do aspirin/plavix x 6 mo. or warfarin x 3 mo.
bioprosthetic valve replacement in Afib
guidelines say to use warfarin within the first 3 months of replacement, but clinically we use DOACs
mechanical heart valve replacement
warfarin only
increase target INR to 2.5 - 3.5 if in the mitral position
can add ASA low dose if indication for anti-platelet therapy
VTE Risk Factors (13)
THE DICE SHOES
elderly (>40)
surgery
cancer
trauma
immobile
Central Line
Estrogen
ESA
Obese
Hx
Smoker
hypercoagulable
disease states (pregnancy, infection, CHF)
Hip Fracture Anticoagulants
Warfarin
Enoxaparin 30mg SC BID
Fondaparinux 2.5mg SC daily
Total Hip Surgery Anticoagulation Options
enoxaparin 40mg SC daily
Dalteparin 5000 SC daily
Fondaparinux 2.5mg daily
apixaban 2.5 BID
rivaroxaban 10mg
dabigatran 110mg, then 220mg daily
warfarin
Total Knee Surgery Anticoagulation Options
Lovenox 30mg SC BID
Fondaparinux 2.5mg daily
dalteparin 2500, then 5000 daily
warfarin
apixaban 2.5mg BID
rivaroxaban 10mg daily
difference in Ortho surgery anticoagulations
40mg SC daily in total Hips
dabigatran in Total Hip Only
Hip Fracture is only Warfarin for Oral options
fondaparinux is the same across the board
dabigatran is only for total hip
edoxaban has no place in therapy
inpatient DVT prophylaxis
dalteparin 5000 units daily
enoxaparin 40mg SC daily
rivaroxaban 10mg daily - extended treatment
heparin 5000 SC q8h or q12h
fondaparinux 2.5mg daily
contraindications to Xarelto as inpatient DVT prophylaxis
active cancer causing stay
GI ulcer in last 3 months
bleed in last 3 months
pulomonary cavity, bleeds, etc
dual antiplatelet therapy
VTE prophylaxis as an inpatient and renal dysfunction
dialysis - heparin
CrCl < 15 - avoid rivaroxaban and apixaban
CrCl <30 - avoid fondaparinux and dabigatran
LMWH dosing in obese and weight cutoffs
> 120kg or BMI >40
enoxaparin 40mg SC BID
heparin 7500 units SC q8hH
fondaparinux 5mg
Heparin dosing VTE
80units/kg bolus, then 18u/kg/hr infusion
Enoxaparin dosing VTE
1mg/kg SC q12h or 1.5mg/kg q24h
CrCl <30 1mg/kg q24h
dalteparin dosing VTE
100units/kg SC q12h
200units/kg SC q24h
fondaparinux dosing VTE
weight <50kg: 5mg
weight 51-100kg: 7.5mg
weight >100kg: 10mg
treatment of VTE with dabigatran or edoxaban
start injectable x 5 days then start dabigatran 150mg BID or edoxaban 60mg daily
what dose does rivaroxaban not need food?
10mg daily or less
duration of anticoagulation with provoked and unprovoked DVT
provoked - 3 months
idiopathic - lifetime
INR Risk Levels
INR < 1.8 increases clot risk by 60%
INR > 4.0 starts to increase bleed risk
dabigatran expiration date and most common ADR
dyspepsia and 4 months after opening
when to give edoxaban after a heparin infusion
4 hours after stopping
which DOACs safer for bleeding than warfarin
apixaban and edoxaban
who to avoid DOACs in
pregnant
hepatic dysfunction
antiphospholipid syndrome
low body weight
bariatric surgery
which DOAC has best data with obesity
rivaroxaban or apixaban
duration of time SCDs have to be on to be effective
18 hours/day
DOC for burns in medically ill
heparin is best
duration of hip replacement and knee replacement VTE prophylaxis
Knee x 10 days
Hip x 35 days
DOC for hemodialysis
Heparin
pregnancy DOC
LMWH or heparin
duration of VTE treatment
1st - 3 mo. if known reason
cancer - 3-6mo. or longer
2nd - indefinite
1st w/o cause - 3 mo. +
1 unit PRBCs raises Hgb _____ g/dl
1 - 2
FFP
fresh frozen plasma
spun out all the protein - mostly clotting factors
similar risks as blood and has to thaw out
must type and cross
Warfarin Reversal
prothrombin complex concentrate
25x more clotting factors than plasma
Factors II, IX, X, VIIa, C and S
does not require type and crossing
Balfaxar and KCentra
25 units/kg INR 2 - 3.9, max 2500 units
35 units/kg INR 4 - 6, max 3500 units
50 units/kg INR >6, max 5000 units
Factor Xa Reversal Agent
Andexanet alfa (Andexxa)
400mg bolus then 4mg/min x 2 hours for apixaban 5 or rivaroxaban 10 or if dose was > 8 hours ago of any strength
800mg bolus then 8mg/min x 2 hours for > apixaban 5mg or rivaroxaban >10mg or if unknown dose/timing of anticoagulant
max dose 1750mg/event, no repeat dosing safety/efficacy data
risk of activated vs inactivated factors
clotting
risks of massive blood transfusions
acidosis
hyperkalemia
citrate-induced hypocalcemia
dilution-induced thrombocytopenia
UFH Reversal
protamine 1mg for every 100 units of heparin
if continuous drip: last 1 hour = full dose, 2nd hour 1/2 of dose, 3rd hour 1/4 of dose
never administer more than 50mg in a single dose
protamine ADR
hypotension, bradycardia
NPH insulin use, vasectomy, sensitivity to fish
LMWH Reversal
protamine will reverse 50-60% of LMWH
Within 8 hours of last dose:
1mg = 1mg enoxaparin = 100 anti-Xa units
> 8 hours from last dose:
0.5mg = 1mg enoxaparin = 100 anti-Xa units
dabigatran reversal
KCentra 25-50 units/kg
idarucizumab 5g IV x 1
reverses in 15 minutes and remains 12 - 24 hours
DOAC Reversal
can use Andexanet alfa or aPCC 25 - 50 units/kg
time to hold DOACs prior to surgery
dabigatran - 1-2 days unless CrCl <50 then 3 - 5 days
apixaban, rivaroxaban, edoxaban
minor or vascular procedures: 1 - 2 days
vascular surgery CrCl <30: 3 - 4 days
