VTE Flashcards
Didnt include VTE prophylaxis
3 main categories of Risk factors for VTE
Hypercoagulability
Vascular damage
Circulatory stasis
S&S of DVT
Symptoms (similar to cellulitis so must be able to differentiate):
- The patient may complain of leg swelling, pain, or warmth, fever (possible also).Symptoms are nonspecific and objective testing must be performed to establish the diagnosis
- Usually presents unilaterally
Signs:
- Superficial veins may be dilated -> “palpable cord” may be felt in affected leg
- Pain in the back of the knee when the examiner dorsiflexes the foot of the affected leg (Homan’s sign).
S&S of PE
Symptoms (more respiratory):
- May come with cough, chest pain, chest tightness, SOB or palpitation
- Symptoms may be confused w MI
- May spit or cough up blood (hemoptysis)
- When massive, may come with dizziness or light-headedness.
Signs:
- May have tachycardia, tachypnea, and appear diaphoretic
- Neck veins may be distended
- Massive PE: may appear cyanotic and become hypotensive. Oximetry: hypoxic
- May go into cardiogenic shock and die within minutes.
Clinical feature of the Wells Score
Active cancer: 1
Paralysis, paresis or recent plaster immobilisation of lower extremeties: 1
Recently bedridden for >3d or major surgery within 4wks: 1
Localised tenderness under distribution of deep venous system: 1
Entire leg swollen: 1
Calf swelling by >3cm when compared to asymptomatic leg: 1
Pitting edema: 1
Collateral superficial veins: 1
Alternative diagnosis as more likely than that of deep venous thrombosis: -2
Scoring of Wells score and its probability of DVT
High probability: >=3
Moderate probability: 1 or 2
Low probability: 0
What should be done if wells-DVT score is 1-2?
D-dimer test as there is moderate/intermediate likelihood of DVT
What does D-dimer negative test suggest?
Rules out DVT
What does D-dimer positive test suggest and what should be done?
Possibility of DVT so send pt for ultrasound
What does wells-DVT score >2 suggests and what should be done?
High likely of DVT so send pt for ultrasound
If ultrasound suggests that it is a proximal DVT, what should be done?
Initiate anticoagulants
If ultrasound suggests that it is a distal DVT, what should be done?
Can either monitor or give anticoagulant
Does a positive D-dimer test always suggests DVT?
No, alot of others conditions can lead to a +ve D-dimer test hence, send pt for ultrasound to confirm
Wells criteria for PE
Clinical smx of DVT (leg swelling, pain with palpitation): 3
Other diagnosis less likely than PE: 3
HR >100: 1.5
Immobilization (>=3days) or surgery in previous 4 wks: 1.5
Previous DVT/PE: 1.5
Hemoptysis: 1
Malignancy: 1
Scoring of Wells criteria and its probability for PE
High: > 6
Moderate: 2-6
Low: <2
At what Wells score does it suggests likelihood of PE?
Wells score >4pts
What should be done is Wells score <= 4 pts for PE?
D-dimer test. If +ve, do imaging.
When are thrombolytics indicated for VTE and why?
Only when there is high risk of death eg. PE with severe cardiopulmonary compromise or DVT with high risk of limb loss.
Thrombolytics have high risk of causing haemorrhagic bleeding and is mainly used in PE > DVT
What is the dose for apixaban in VTE?
10mg PO BD x 7d then 5mg BD up to 6months.
Optional: 2.5 BD after first 6months
What is the dose for rivaroxaban in VTE?
15mg PO BD x 21d then 20mg daily up to 6months
Optional: 10mg daily after first 6months
If dabigatran or edoxaban is used as the DOAC, what should be given during the acute phase of VTE?
UFH or LMWH for first 5days
LMWH more commonly used
What factor does the ~xabans inhibit?
Factor Xa
Rank the DOACs and warfarin according to which is most renally cleared
Dabigatran > Rivaroxaban > Apixaban > Edoxaban (50% renal, 50% liver) > Warfarin
This is also in increasing hepatic clearance
What is the advantage of warfarin over DOACs?
Can be used in renal impairment
Has a reliable measurement assay (i.e INR)
Effects of DDI can be monitored
Can be used if pt has antiphospholipid antibody syndrome
What is the advantage of DOACs over warfarin?
Fixed dosing, dont need to titrate
Fewer DDI and food drug interactions
No initial parenteral agent, except dabigatran
What is dabigatran dose for VTE Tx?
Parenteral anticoagulant (UFH or LMWH) for >=5days followed by 150mg BD
LMWH more commonly used
What is edoxaban dose for VTE Tx?
Parenteral anticoagulant (UFH or LMWH) for >=5days followed by 60mg/day
LMWH more commonly used
When should dabigatran be avoided?
CrCl < 50ml/min and concomitant PGP inhibitors
When should rivaroxaban be avoided?
CrCL < 30ml/min
When should apixaban be avoided?
HSA guidlines:
CrCL 15-29: use with caution
HD: avoid
How to dose adjust for edoxaban?
CrCL 30-50ml/min or BW <=60kg: 30mg/day
Note: not rec if CrCL > 95ml/min
How is warfarin titrated?
Individualised and according to target INR of 2-3
Which of the following RFs is/are transient in the context of consideration of VTE treatment duration?
a) Immobility due to hip replacement surgery
b) Immobility due to lower limb injury requiring casts
c) Presence of antiphospholipid syndrome
d) Infection or sepsis
a, b, d
Which of the following could be used to differentiate DVT/PE from fluid overload due to HF exacerbation?
a) Presence of fever
b) Unilateral LL swelling, pitting edema on affected limb > other limb.
c) Tachypnoea
d) D-dimer levels
a, b, d
Which of the following is/are appropriate for an established provoked proxDVT (without PE) in a 62kg pt?
a) Rivaroxaban 15mg BD x 7d followed by 15mg OM for 3months
b) Apixaban 10mg BD x 7d followed by 5mg BD for 3m
c) SC Enoxaparin 60mg BD x 5d followed by dabigatran 150mg BD for 3m
d) Warfarin w SC Enoxaparin 65mg BD cover until INR reaches 2.
b, c
Which of the following drugs is/are correctly paired with their MOA?
a) Warfarin - inhibits VKOR-dependent clotting factors II, VII, IX, X prdtn
b) Rivaroxaban - direct thrombin inhibitor
c) Tenecteplase - promotes fibrinolysis by converting plasminogen to plasmin
d) Dabigatran - anti Xa inhibitor
a, c
What is the usually duration for DOAC in VTE?
3 months. Extend beyond 3months if there are unprovoked risk factors
What should be given if pt is unstable and at high risk PE?
Anticoagulation with UFH, including weight-adjusted bolus injection.
What is advantage of using UFH over LMWH?
Easily reversible due to shorter half life
Among the thrombolytics, which is used in PE?
rTPA (alteplase)
What should be given for VTE during pregnancy?
LMWH. Avoid warfarin and DOAC
What is the dose of enoxaparin?
1mg/kg SQ every 12hr
How to renally dose adjust enoxaparin?
CrCL < 30ml/min: 1mg/kg QD
What defines haemodynamic instability which suggests high risk PE?
- Need cardiopulmonary resuscitation
- SBP < 90mmHg and end-organ hypoperfusion
- SBP < 90mmHg or systolic BP drop >=40mmHg lasting longer than 15min and not caused by new-onset arrhythmia, hypovolemia, or sepsis
Which strength/syringe of enoxaparin is graduated?
60mg and 80mg are graduated syringe
40mg is non-graduated so cant half it.
UFH or LMWH is preferred for PCI procedures?
UFH
