VTE and Anticoagulation and Supratherapeutic INR

Question 1

Who should not get DOAC?

Answer 1

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

Question 2

1st time provoked VTE treatment

Answer 2

3 months of AC and then discontinue therapy

Question 3

Finite extension of duration of AC (for total of 6-12 months) for VTE is if there’s

Answer 3

temporary persistence of provoking factor (prolonged immobility)

Question 4

provoking factors for VTE

Answer 4

surgery, trauma immobolization >3 days pregnancy and estrogen use active malignancy

Question 5

1st time UNprovoked VTE therapy should be

Answer 5

indefinitely AC unless high bleeding risk

don’t need to test for underlying prothrombotic states.

Question 6

Testing for thrombophilia is recommended if:

Answer 6

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.

Question 7

superficial thrombophlebitis clinical features

Answer 7

tenderness, pain, induration, erythema along the superificial vein

possible palable nodular cord within affected vein

fever and purulent dranage suggests suppurative thrombophlebitis

Question 8

indications for U/S LE

Answer 8

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)

Question 9

risk factors for superficial vein thrombophlebitis

Answer 9

venous stasis, venous excision/ablation, malignancy.

Question 10

prognosis of superficial vein thrombophlebitis

Answer 10

normally good prognosis but also can coexisit with DVT or PE and so need to rule this out

Question 11

high risk for developing DVT with superficial vein thrombophlebitis need

Answer 11

further evaluation with U/S

PE before deciding on treatment

Question 12

superficial vein thrombophlebitis without DVT treatment

Answer 12

leg elevation, warm and cold compresses and NSAIDS for 7-10 days

Question 13

anticoagulation for superficial vein thrombophlebitis indications

Answer 13

increased risk for DVT,

those with superficial vein thrombosis >5 cm,

anatomical proximity of thrombus to deep vein system <5cm

medical risk factors

Question 14

after a DVT, best recommendation is for

Answer 14

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

Question 15

when should pts who have a dVT resume ambulation?

Answer 15

unclear but mobilization is appropriate as soon as therapeutic levels of AC is achieved

(ex within 24 hours after starting anticoagulation.

Question 16

low probability for VTE what to order:

Answer 16

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

Question 17

High probability for VTE what to order:

Answer 17

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.

Question 18

VTE algorithm

Answer 18

Question 19

pts with cancer are at much higher risk for VTE?

Answer 19

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.

Question 20

unfractionated heparin is

Answer 20

IV heparin with short half life. Not the same thing as low molecular weight heparin.

Question 21

dabigatran inhibits

how to measure if anticoagulated or not?

Answer 21

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

Question 22

pts on dabigatran undergoing elective procedures are advised to

Answer 22

stop medication within 48 hrs of operation

1/2 life is 12 hrs. do not need a thrombin time.

Question 23

anticoagulation with pregnancy

Answer 23

Question 24

pregnancy and post partum period are risk factors for VTE because

Answer 24

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.

Question 25

anticoagulation during with delivery for someone who has a VTE:

Answer 25

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.

Question 26

who gets outpatient care for VTE?

Answer 26

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.

Question 27

phlegmasia cerulea dolens is called:

Answer 27

massive iliofemoral DVT

need IV heparin and definitive therapy with thrombolysis or thrombectomy.

Question 28

who gets supportive care and not AC?

Answer 28

superficial thrombophlebitis or below the knee that is not in close proximity to deep vein system.

All proximal DVT needs AC

Question 29

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 :

Answer 29

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.

Question 30

young person without risk factors gets a stroke or a VTE, you should test for

Noted they have thrombocytopenia too

Answer 30

antiphospholipid antibody syndrome

Question 31

very high risk conditions and high risk conditions that may require bridging for AC or minimization of risk

Answer 31

Question 32

If someone needs to get surgery for elective laminectomy and has a DVT what to do?

Answer 32

delay the surgery until completion of treatment with AC for DVT.

Laminectomy is a high risk for bleeding procedure.

Question 33

If someone has a peripancreatic tumor that needs biospy and has a mechanical mitral valve what to do for his anticoagulation

Answer 33

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.

Question 34

initial approach to elevated INR:

Answer 34

degree of elevation

presence of active bleeding

pts bleeding risk

indications for continued warfarin therapy after episode resolves

Question 35

warfarin can have an elevated INR due to

Answer 35

drug drug interactions,

vitamin K deficiency

super imposed conditions (diarrhea), fever, liver disease and heart failure.

Question 36

how to manage someone who’s INR is <5 on warfarin?

Answer 36

hold warfarin for 1-2 doses and then consider reducing maintenance dose

Question 37

How to manage pt who has INR 5-9 and on warfarin and is not bleeding?

Answer 37

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.

Question 38

If someone has INR>9 and on warfarin and no bleeding:

Answer 38

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

Question 39

management for life threatening bleeding at any INR level

Answer 39

hold warfarin,

immediate reversal of INR with slow IV vitamin K infusion

fresh frozen plasma

IV prothrombin complex

Question 40

enoxaparin dosing is with

Answer 40

1mg/kg actual body weight q12h or

1.5 mg/kg actual body weight daily

Question 41

prefer enoxaparin for:

Answer 41

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

Question 42

if there’s cancer and pt is undergoing surgery, what is prophylaxis?

how long is duration of prophylaxis?

Answer 42

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.

Question 43

pt has cancer and undergoing major abdominal or pelvic surgery with high risk features like a residual cancer or obesity

Answer 43

extend post operative prophylaxis up to 4 weeks

Question 44

if we try to test for protein C and S deficiency or antithrombin in acute DVT will that help?

Answer 44

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.

Question 45

Do we ever repeat U/S for DVT after 3 months of AC?

Answer 45

no. not helpful for determining duration of AC.