VTE and Anticoagulation and Supratherapeutic INR Flashcards
Who should not get DOAC?
pts with renal failure or CrCl<30 or ESRD pts with valvular heart disease (mitral stenosis, prosthetic heart valves severe decompensated valvular dx needing valve replacement pregnant pts cirrhotics
1st time provoked VTE treatment
3 months of AC and then discontinue therapy
Finite extension of duration of AC (for total of 6-12 months) for VTE is if there’s
temporary persistence of provoking factor (prolonged immobility)
provoking factors for VTE
surgery, trauma immobolization >3 days pregnancy and estrogen use active malignancy
1st time UNprovoked VTE therapy should be
indefinitely AC unless high bleeding risk
don’t need to test for underlying prothrombotic states.
Testing for thrombophilia is recommended if:
high risk of thrombophilia
recurrent VTE or VTE in unusual location (portal vein, dural venous sinus)
family history of VTE at a young age - as this may affect OCP or perioperative anticoagulation use.
In general population pts >50 yrs or presence of protein C or S deficiency, Factor 5 Leiden or other prothrombotic states do not change AC decision or duration of testing.
superficial thrombophlebitis clinical features
tenderness, pain, induration, erythema along the superificial vein
possible palable nodular cord within affected vein
fever and purulent dranage suggests suppurative thrombophlebitis
indications for U/S LE
superficial vein thrombosis >5 cm
long superficial thrombosis in proximity <5 cm to the deep vein system (saphrofemoral and saphenopopliteal junction)
involvement of great or small saphrenous vein
more lower extremity swelling than expected
superficial phlebitis following vein ablation therapy (laser or radiofrequency)
risk factors for superficial vein thrombophlebitis
venous stasis, venous excision/ablation, malignancy.
prognosis of superficial vein thrombophlebitis
normally good prognosis but also can coexisit with DVT or PE and so need to rule this out
high risk for developing DVT with superficial vein thrombophlebitis need
further evaluation with U/S
PE before deciding on treatment
superficial vein thrombophlebitis without DVT treatment
leg elevation, warm and cold compresses and NSAIDS for 7-10 days
anticoagulation for superficial vein thrombophlebitis indications
increased risk for DVT,
those with superficial vein thrombosis >5 cm,
anatomical proximity of thrombus to deep vein system <5cm
medical risk factors
after a DVT, best recommendation is for
early ambulation and this does not increase risk for PE after being on AC. Early ambulation also showed more rapid improvement in pain nad lower risk for: DVT extension, PE, mortality, and post thrombotic syndrome
when should pts who have a dVT resume ambulation?
unclear but mobilization is appropriate as soon as therapeutic levels of AC is achieved
(ex within 24 hours after starting anticoagulation.
low probability for VTE what to order:
order a moderate to high sensitivity d dimer Rules out D dimer (sensitivity up to 96% but specificity is low) If low, needs to get a compression U/S
High probability for VTE what to order:
proceed to compression U/S and has a diagnostic sensitivity of 97% for VTE There are false negatives that happen 3% of the time and so need to repeat U/S within days. Especially if there’s elevated D dimer and remain symptomatic and no clear alternate diagnosis.
VTE algorithm
pts with cancer are at much higher risk for VTE?
4-7X greater risk.
Need to be treated with low molecular weight heparin. DO not use unfractionated heparin due to short half life as OP. Only used inpatient as IV gtt.
unfractionated heparin is
IV heparin with short half life. Not the same thing as low molecular weight heparin.
dabigatran inhibits
how to measure if anticoagulated or not?
direct thrombin inhibitor
normal thrombin time - not anticoagulated and so surgery can proceed
elevated thrombin - anticoagulated and administration of dabigatran antidote idarucizumab in life threatening bleeding
pts on dabigatran undergoing elective procedures are advised to
stop medication within 48 hrs of operation
1/2 life is 12 hrs. do not need a thrombin time.
anticoagulation with pregnancy
pregnancy and post partum period are risk factors for VTE because
increased procoagulant factor, decreased protein S activity.
also increased venous capacity and compression of IVC and iliac veins cause lower extremity venous stasis.
All worsened with inactivity and bed rest.
anticoagulation during with delivery for someone who has a VTE:
hold anticoagulation with low molecular weight heparin for 24 hrs prior to delivery. During the 24 hrs, high risk for recurrenct (acute PE, proximal dvt within the last month), and so switch to unfractionated heparin (IV heparin) and then discontinued 4-6 hrs prior to surgery or delivery
Then anticoagulation is started 6 to 12 hrs after delivery and continued for >6 weeks post partum.
who gets outpatient care for VTE?
minimal risk factors for complications and provoked DVT
- people who are HDS
- low risk for bleeding
- normal kidney function
- reliable social environment for administration of AC.
PTs who have large clot burden (iliofemoral DVT or concomitant PE should not be OUTPT management. Or if has CHF should stay inpt.
phlegmasia cerulea dolens is called:
massive iliofemoral DVT
need IV heparin and definitive therapy with thrombolysis or thrombectomy.
who gets supportive care and not AC?
superficial thrombophlebitis or below the knee that is not in close proximity to deep vein system.
All proximal DVT needs AC
what is the protocol for very high risk pts of thrombosis and need to be on warfarin (mechanical mitral valve) strategy prior to procedure is :
stop warfarin 5 days prior and once INR<2 then start unfractionated heparin (IV)
heparin should be stopped day of procedure and restarted 24 to 48 hrs after and then in combo with warfarin
Mitral valve has relatively stagnant blood flow compared to aortic valve and that’s why at higher thrombotic risk.
young person without risk factors gets a stroke or a VTE, you should test for
Noted they have thrombocytopenia too
antiphospholipid antibody syndrome
very high risk conditions and high risk conditions that may require bridging for AC or minimization of risk
If someone needs to get surgery for elective laminectomy and has a DVT what to do?
delay the surgery until completion of treatment with AC for DVT.
Laminectomy is a high risk for bleeding procedure.
If someone has a peripancreatic tumor that needs biospy and has a mechanical mitral valve what to do for his anticoagulation
given it’s a moderate thrombotic risk and one extra risk factor for stroke (HTN) this is a high thrombotic risk condition.
Anyone with moderate to high thrombotic risk needs hold warfarin for 5 days until INR falls <1.5 and then perform procedure
can be resumed following evening without need for bridging.
initial approach to elevated INR:
degree of elevation
presence of active bleeding
pts bleeding risk
indications for continued warfarin therapy after episode resolves
warfarin can have an elevated INR due to
drug drug interactions,
vitamin K deficiency
super imposed conditions (diarrhea), fever, liver disease and heart failure.
how to manage someone who’s INR is <5 on warfarin?
hold warfarin for 1-2 doses and then consider reducing maintenance dose
How to manage pt who has INR 5-9 and on warfarin and is not bleeding?
hold the warfarin 1-2 doses and reduce the maintenance dose.
If they are older age or history of bleeding also give low dose oral vitamin K.
If someone has INR>9 and on warfarin and no bleeding:
temporarily stop warfarin and give high dose oral vitamin K as risk for major bleeding is 10-20%
oral vitamin K is preferred as it is effective as IV vitamin K and lowers INR in 48 hrs as is associated with a lower risk of anaphylaxis compared to IV vitamin K
management for life threatening bleeding at any INR level
hold warfarin,
immediate reversal of INR with slow IV vitamin K infusion
fresh frozen plasma
IV prothrombin complex
enoxaparin dosing is with
1mg/kg actual body weight q12h or
1.5 mg/kg actual body weight daily
prefer enoxaparin for:
cancer pts
extensive clot burden
actual body weight between 101-105kg or 222-330 or BMI between 30 or 40
Cannot use in pts who have CKD4 or CKD5
if there’s cancer and pt is undergoing surgery, what is prophylaxis?
how long is duration of prophylaxis?
extend duration of thromboprophylaxis for people undergoing surgery if they have cancer
need to get prior to surgery and 7 to 10 days after surgery.
pt has cancer and undergoing major abdominal or pelvic surgery with high risk features like a residual cancer or obesity
extend post operative prophylaxis up to 4 weeks
if we try to test for protein C and S deficiency or antithrombin in acute DVT will that help?
no because Protein C and S and antithrombin 3 are low anyway in acute thrombus. NO need to test as this won’t affect management.
Do we ever repeat U/S for DVT after 3 months of AC?
no. not helpful for determining duration of AC.
