DVT & PE

Question 1

What are the risk factors for DVT?

Answer 1

• Smoking
• Prolonged Bed Rest
• APLS (Recurrent Miscarriages)
• Obesity
• Immobility
• Pregnancy
• Recent Surgery
• OCPs
• Cancer
• Long Haul Flight
• HRTs

Question 2

What is the DDx to unilateral leg swelling?

Answer 2

• Deep Vein Thrombosis
• Compartment Syndrome (recent trauma etc)
• Cellulitis
• Necrotising Fasciitis (severely toxic patient)

Question 3

When can you exclude DVT?

Answer 3

2 of the 3 are -ve: Well’s Score, D-Dimers, USS

Question 4

What is the acute management of DVT?

Answer 4

Acutely anticoagulate to prevent clot propagation 🡪 AFTER confirming Dx w/ USS

Options:

• LMWH
• DOACs: Apixaban, Rivaroxaban, NOT Dabigatran
• Dabigatran requires a bridging therapy of Parenteral anticoagulation for 5/7

Because unlike CTPA for PE, Doppler USS is much faster, hence we can confirm Dx before starting anticoagulation

Consider:

• Thrombolysis / Thrombectomy if
  1) EXTENSIVE / PROXIMAL THROMBOSIS not responding to anticoagulation therapy
  2) Phlegmasia cerulea dolens (literally: painful blue inflammation)

Question 5

What is the chronic management of DVT?

How about for cancer patients?

How about for pregnant ladies?

Answer 5

[Long Term anticoagulation AFTER establishing diagnosis]

Options:

• Warfarin: requires 5 days of bridging w/ either LMWH or DOACs; therapeutic INR of 2-3
• DOACs: Dabigatran, Apixaban, Rivaroxaban

Duration

• For 3-6M for 1st case of DVT
• Indefinitely for recurrent DVT / Hypercoagulable state (such as Ca)

If anticoagulation is C/I 🡪 consider IVC Filter

For all patients: Compressive Stockings and Early Mobilisations

Question 6

What is the drug choice in extensive DVT or massive PE?

Answer 6

Heparin: these patients were excluded from trials with NOACs

Question 7

What is the drug choice in patients with high initial risk of bleeding?

Answer 7

Heparin: enable dose titration, rapid offset and availability of protamine as antidote

Question 8

What is the drug choice in patients with cancer?

Answer 8

• Initial therapy: LMWH, UFH, Rivaroxaban

- Maintenance therapy: LMWH > Rivaroxaban or Edoxaban > Warfarin

Question 9

What is the drug choice in pregnant patients ?

Answer 9

Pregnancy – both are C/I hence use LMWH

Question 10

What is the drug choice in patients with liver dysfunction with increased prothrombin time?

Answer 10

Warfarin

Question 11

What is the drug choice in patients with creatinine clearance <30mL/min?

Answer 11

Warfarin

Question 12

What is the drug choice in patients with creatinine clearance 30-50mL/min?

Answer 12

Rivoraxaban, apixaban or edoxaban –> less affected by renal impairment than dabigatran

Question 13

What is the drug choice in patients with dyspepsia or upper GI symptoms?

Answer 13

Rivoraxaban, apixaban or edoxaban

Question 14

How do you manage thrombosis of superficial vein?

Answer 14

Thrombosis of superficial vein is NOT true DVT 🡪 don’t need to treat

• Can tell difference between superficial and deep via USS
• Mx: repeat USS in 3/12; Give advice to come back if swelling gets worse, symptoms of PE, then rescan them
• Exception: Thrombosis of superficial femoral vein IS CONSIDERED a deep vein

Question 15

What are the investigations needed if patients are haemodynamically stable?

Answer 15

ECG

• Most sensitive: sinus tachy
• Most specific: S1Q3T3

CXR – Westermark’s sign, Hamptom’s hump

UECr – becuase of DOAC use

ABG – Respiratory alkalosis, desaturation, respiratory failure

BP – obstructive shock

USS Doppler – looking for DVT

TTE – looking for RV dilatation, Tricuspid regurgitation

CTPA – diagnostic

Question 16

What is the management of haemodynamically stable patient with PE?

Answer 16

1) Acute Resuscitation: Airway, Breathing & Circulation
- Oxygen – 100% via non-rebreather mask
- Set IV access. Send baseline bloods, including clotting. Perform ECG
- Analgesia if required

Calculate Well’s Score

• If HIGH LIKELIHOOD (i.e. score >4) – proceed to (3)
• If LOW LIKELIHOOD (i.e. score ≤4): Risk stratify based on D-Dimers levels (very sensitive, not specific)
• If Elevated – proceed to (3)
• If Not-Elevated – evaluate for other causes of dyspnoea

3) Start Empirical Acute Anticoagulation unless active GI bleed or intracerebral haemorrhage. - LMWH: Bolus dose 5000-10000 units or 80 IU/kg. Maintenance infusion rate until APTT is 1.5-2.5 x control. Check APTT 4-6hr after initial bolus
- DOACs: Apixaban, Rivaroxaban, NOT Dabigatran

4) Send the patient for confirmatory CT Pulmonary Angiogram

5) +ve diagnosis 🡪 SYMPTOMATIC / SUPPORTIVE TREATMENT
- Thrombolysis / Thrombectomy is NOT necessary for stable patient

6) Followed by long term anticoagulation
- Warfarin – requires 5 days of bridging w/ either LMWH or DOACs; therapeutic INR of 2-3
- DOACs – Dabigatran, Apixaban, Rivaroxaban
Duration
- For 3-6M for 1st case of DVT
- Indefinitely for recurrent DVT / Hypercoagulable state (such as Ca)
- If anticoagulation is C/I 🡪 consider IVC Filter

Question 17

What is the management of acute massive PE?

Answer 17

1) Acute Resuscitation: Airway, Breathing & Circulation
- Oxygen – 100% via non-rebreather mask
- Set IV access. Send baseline bloods, including clotting. Perform ECG
- Analgesia if required
- Manage Cardiogenic Shock – Fluids & inotropes (NE preferred) may be required in sub-massive / massive PE to maintain RV filling

2) Achieve diagnosis via:
- If STABLE after resuscitation 🡪 Send for CTPA for definitive Dx
- If UNSTABLE after resuscitation 🡪 TTE for features of RV dysfunction (RV dilatation, Pulmonary HTN) for presumptive
diagnosis
- NO NEED FOR WELL’S SCORE! Because this is an emergent setting

3) Thrombolysis – 1st line management!
- If no active GI bleed or Cerebral haemorrhage
- Alteplase 100mg/2h peripherally

4) Thrombectomy – indications:
- massive proximal pulmonary embolism with hemodynamic compromise
contraindications to thrombolysis
- No improvement after thrombolysis

5) Followed by long term anticoagulation