CV thromboembolsm Flashcards
whats the difference between DVT, PE, and VTE?
VTE? Blood clot in a vein- blocks blood flow
DVT? Legs/pelvis- unilateral localised pain/swelling
PE? Lungs- chest pain/SOB/ cough
risk factors for VTE?
surgery
trauma
significant immobility
malignancy
obesity
pregnancy
hormonal therapy (COC/ HRT)
what test is done for VTE diagnosis?
D-dimer
counselling point for pt going on long haul flight?
walk around plane or wear stockings
2 methods of thromboprophylaxis
mechanical
pharmacological
mechanical thromboprophylaxis includes what?
graduated compression stockings, wear until plane sufficiently mobile
pharmacological thromboprophylaxis includes what? and when are they started?
anticoagulants, start within 14hrs of admission
patients with risk factors for bleeding (stroke, thrombocytopenia..)- ONLY receive prophylaxis (anticoags) when ?
when their risk of VTE outweighs risk of bleeding.
what tools used to assess bleeding risk?
ORBIT/ HASBLED
0-2 low
3 medium
4-7 high
surgery and VTE. mechanical prophylaxis, keep using until when?
pt sufficiently mobile/ discharged from hospital
pharmacological tx for vte prophylaxis following surgery which is most common?
LMWH is suitable in all types of general and orthopaedic surgery
vte prophylaxis following surgery, what drug is preferred in renal impairment
Unfractionated heparin
vte prophylaxis following surgery, what drug is preferred in cases of lower limb immob or pelvis fragility fractures/ knee replacement
Fondaparinux
general surgery pts AND general med pts with high risk of VTE should be given pharmacol prophylaxis for how long post surgery?
7 days or until sufficient mobility
however,
28 days after major cancer surgery in abdomen
30 days in spinal surgery
difference between unfractioned and LMWH
unfractioned has much shorter t1/2 thus useful in pts w renal impairment due to accum of drug
if pt develops bleed, unfractioned heparin can be stopped, due to short t1/2 bleeding will also stop
three options for vte prophylaxis following elective HIP replacement?
LMWH for 10 days AND THEN 75mg aspirin for 28 days
LMWH for 28 days+stockings till discharge
Rivaroxaban- 10mg OD, 5 weeks
three options for vte prophylaxis following elective KNEE replacement?
75mg aspirin for 14 days
LMWH for 14 days+stockings till discharge
Rivaroxaban- 10mg OD, 2 weeks
thromboprophylaxis in pregnancy - not every woman needs anticoagulation. when is it given?
when risk of VTE outweighs risk of bleeding
what pregnant women may be considered for vte prophylaxis? and what drug given?
Birth/miscarriage/termination during past 6 weeks: start LMWH 4-8hrs after event, continue for 7 days
if risk of vte outweighs risk of bleeidng in pregnant women, LMWH given during hospital admission and continued until when?
in preg women
until no risk of vte/ till pt discharged
additional mechanical prophylaxis considered in pregnancy if immobilised and continued until how long?
sufficiently mobile/ discharged
LMWH usually used to treat vte, but unfractioned heparin may be used in pt with high risk of what?
haemorrhage
and need to have anticoag quickly
short t1/2
first line treatment of confirmed DVT/ PE?
apixaban/ rivaroxaban
second line tx of confirmed DVT/PE?
LMWH for at least 5 days, then dabigatran/edoxaban
LMWH+warfarin for at least 5 days/till INR at least 2, 2 readings, then warfarin alone
what to do if anticoagulation treatment fails?
assess adherence and other potential sources of hypercoagulability;
increase dose/change to anticoagulant with different moa
duration of anticoag treatment for distal DVT (calf)
6 weeks
duration of anticoag treatment for proximal DVT/ PE?
at least 3 months (3-6 for those with active cancer)
duration of anticoag treatment for provoked DVT/ PE i.e. done something to cause it like being immobile or using coc
stop at 3 months if provoking factor resolved
duration of anticoag treatment for unprovoked DVT/ PE
eg if pt has underlying condition they can’t control causing the dvt e.g. age/ cancer
3 months +
duration of anticoag treatment for recurrent DVT/ PE
long term
warfarin is a high risk drug, vitamin k antagonist
why is INR monitored?
higher INR = thinner blood
what INR to maintain in VTE/AF/Cardioversion/MI/Cardiomyopathy?
2.5 (+/- 0.5)
what INR to maintain in Recurrent VTE/Mechanical heart valves?
3.5
for more invasive conditions
what to do with warfarin in cases of major bleed?
stop warfarin -> IV phytomenadione (vitamin K)+dried prothrombin
what to do if warfarin pt has INR >8, minor bleeding?
stop warfarin - IV phytomenadione
what to do if warfarin pt has INR >8, no bleeding?
Stop warfarin - oral phytomenadione
what to do if warfarin pt has INR 5-8, minor bleeding?
Stop warfarin - IV phytomenadiaone
what to do if warfarin pt has INR 5-8, no bleeding?
Withhold 1-2 doses of warfarin+reduce subsequent dose
in cases of increased INR, when should warfarin be restarted?
Restart warfarin when INR<5
when to monitor inr on warfarin?
every 1-2 days in early tx
then every 12 weeks
essentially, if there is a minor bleed in pt on warfarin with high INR eg nose/ gum blees give IV/ ORAL phytomenadione
IV
essentially, if there is NO bleed in pt on warfarin with high INR give IV/ ORAL phytomenadione
oral only if INR >8
if INR 5-8 withold 1-2 doses of warfarin
side effects of warfarin 3
skin necrosis and calciphylaxis (painful rash)
haemorrhage: prolonged bleeding
pregnancy: avoid in 1st and 3rd trim (or altogether. teratogenic) use contraception
whats the antidote for haemorrhage
vit K1 (phytomenadione)
what foods and drink does warfarin interact with?
VITAMIN K RICH FOODS- avoid major diet changes with leafy greens, reduces efficacy of warfarin
POMEGRANATE+CRANBERRY JUICE- increases INR
*no interactn with grapefruit
what otc gel interacts with warfarin, increases INR
miconazole (OTC Daktarin)
warfarin interacts with cyp250 inhibs and inducers such as?
inhib (inc conc): fluconazole, macrolides
induc (dec conc): phenytoin, carbamazepine, rifampicin
minor surgery procedures only performed in warfarin pts in low risk of bleeidng… what INR?
less than 2.5
stop warfarin and restart 24 hrs post procedure
when to stop warfain in surgery procedures whererisk of severe bleeding?
3-5 days before
INR equal to/>1.5? Give vitamin K day before surgery
High risk of thromboembolism? Bridge with LMWH, stop LMWH 24hrs before surgery, restart LMWH 48hrs after
EMERGENCY SURGERY?
if can be delayed by 6-12 hrs?
if CAN’T be delayed by 6-12hrs?
eg non servere emergency like appendicitis? Give IV vitamin K
eg car crash? IV vitamin K+dried prothrombin complex
(same as what you give for major bleed!)
why are we trying to shift form warfarin to DOAC use?
less monitoring
what doacs have OD dose and which have BD dose?
HINT: READ
OD: RE.AD: BD
apixaban general dose tx of DVT/ PE
10mg BD for 7 days -> 5mg BD
rivaroxaban dose for DVT/ PE tx?
15mg BD for 3 weeks-> 20mg OD, should be taken with food
what to do if missed dose of rivaroxaban?
take ASAP, dont double dose
t/f with rivaroxaban you can crush and mix in apple puree
true
which doac dose depends on:
pt age?
pt weight?
dabigatran
edoxaban
dabigatran dose for tx of dvt/ pe?
150mg BD aged 18-74
110-150mg BD, aged 75-79
110mg BD, aged 80+
edoxaban dose for tx of dvt/ pe?
60mg OD, 30mg OD if <61kg
Parenteral Anticoagulants- HEPARIN vs LMWH?
all heparins should be avoided when?
in heparin induced thrombocytopenia
heparins can cause what elec imbalance?
hyperkalaemia
Haemorrhage- treat with PROTAMINE SULPHATE (used for unfractionated heparin)
Quick initiation+elimination of unfractioned heparin ideal in what?
high bleeding risk (monitor APTT)
very short t1/2 ideal for closely monitoring pts eg every 2hrs while doing APTT tests
whys unfractioned heparin preferred in renal impairment?
short t1/2
which heparin preferred in pregnancy?
LMWH
