DVT/PE

Question 1

Define DVT

Answer 1

Blood clot/thrombus formation in the deep veins.
Commonly the popliteal, femoral or common iliac veins.

Question 2

What is the aetiology of a DVT?

Answer 2

Triad of factors: Hypercoagulability, endothelial dysfunction, abnormal blood flow
Leads to formation of a blood clot in a vein - prevents venous drainage, leads to a back flow of blood.

Question 3

What are the risk factors for a DVT/PE?

Answer 3

Previous(current) DVT/PE
Immobility (long haul flights, recent surgery)
Genetic - FV leiden or prothrombin mutation.
Active cancer
Pregnancy/post partum
Age - more common in older individuals
Male
Heart failure
Acquired or familial thrombophilia
Combined oral contraceptive pill / pregnancy
Inflammatory disorders (IBD, vasculitis)
Trauma to a vein
Dehydration
SLE thrombophilia

Question 4

What are the signs and symptoms of a DVT?

Answer 4

Localised pain and swelling in one leg
Tenderness, skin changes including oedema, redness, and warmth.
Vein distention.
May have low grade pyrexia

Question 5

What is the acute treatment options for a DVT/PE?

Answer 5

DOAC licensed for treatment of DVT include
Apixaban - 10mg BD 7/7, maintenance 5mg BD
Dabigatran
Edoxaban
Rivaroxaban

Warfarin is also licened for treatment and prophylaxis of DVT and PE

Question 6

What are some potential complications of a DVT?

Answer 6

PE
Chronic venous insufficiency
Post-thrombotic syndrome

Question 7

Define Pulmonary embolism.

Answer 7

Life threatening conditions - Embolism (usually a venous thromboembolism) blocks the pulmonary arteries - preventing blood flow to the lungs - resulting in a V/Q mismatch - leading to respiratory distress.

Question 8

What are the sign and symptoms of a PE?

Answer 8

Symptoms: Acute severe dyspnoea, Hemoptysis, pleuritic chest pain, syncope, cough, features of a DVT
Signs: hypoxemia, hypocapnia, tachycardia, tachypnoea, low grade fever
1 in 4 = sudden death

Question 9

How will a PE present on resp/cardio examination?xx

Answer 9

Obs - tachycardia, tachypnoea. central and peripheral cyanosis.
Crackles, wheeze, pleural frication rub on lung ausculatation
Decreased vocal resonance
Dullness on percussion (fluid)
Loud second heart sound, wide split second heart sound, right ventricular gallop

Question 10

What investigations should be done for a PE?*

Answer 10

Bedside: Wells score, ECG, echo
Bloods:Coagulation screen, D-dimer, ABG
Imaging: CXR (enlarged PA, wedge shape opacity), CTPA, V/Q scan

Question 11

What are some potential complications of a PE?

Answer 11

Sudden death
Cor pulmonale
Arrythmia
MI
Pleural effusion
Risk of haemorrhage from anti-coagulation treatment.

Question 12

What is the acute treatment for a massive PE?

Answer 12

If hemodynamic compromise
Continuous infusion of unfractionated heparin and consider thromblysis (fibrinolytic such as alteplase) IV by a peripheral cannula or central catheter directed into pulmonary arteries.

Question 13

What clinical score is used to predict the probability of a PE?*

Answer 13

Wells Score

Question 14

What is the relevant differential diagnosis of DVT?*

Answer 14

Cellulitis
Popliteal aneurysm
Physical trauma (achilles tendon rupture)
Cardiovascular disorders - superficial thrombophlebitis/post-thrombotic syndrome
Ruptured Bakers cyst
Dependent oedema.

Question 15

What investigations should be done for a DVT?

Answer 15

Bedside:
Bloods: Coagulation screen, D-dimer
Imaging: Doppler ultrasound/ duplex ultrasound
Other: two-level wells score

Question 16

What is the purpose of the two-level DVT wells score?
What do the results mean?

Answer 16

Calculate the likelihood of a DVT being the correct differential diagnosis.
3 or above - high risk - likely DVT
1/2 - moderate risk
0 or below - unlikely

Question 17

How do you calculate a two-level DVT wells score?

Answer 17

Plus one to score for:
Active cancer
Bedridden >3days within 12w
Calf swelling >3cm compared to other leg - measure 10cm below tibial tuberosity.
Collateral superficial veins present
Entire leg swollen
Localised tenderness along the deep venous system
Pitting oedema
Paralysis, paresis or recent plaster immobilisation of lower extremity
Previous document DVT

Loose two points for:
Alternative diagnosis to DVT as likely or more likely.

Question 18

How does the DVT two-level wells score affect the management of the patient?

Answer 18

Question 19

What/when is intermin anti-coagulation offered to suspected DVT patients?

Answer 19

With Wells likely score but ultrasound not available within 4 hrs.
With wells unlikely but D-dimer result not available within 4 hrs

Offer apixaban or rivaroxaban first line for 5/7, then dabigatran/edoxaban for 5/7.
Second line: LMWH + VitK (warfarin) antagonist for initial 5/7.

Question 20

What is the long term management of a DVT/PE?

Answer 20

Maintenance treatment with an oral anticoagulant - warfarin, apixaban, diabigatran etc
Usually for atleast 3 months.
Warfarin requires monitoring for INR between 2-3
DOAC do not need monitoring.
If DVT was unprovoked investigate for the possibility of underlying cancer and thrombophilia testing

Question 21

What is the use of a D-dimer in a DVT/PE diagnosis?

Answer 21

95% sensitive but not specific
A low d-dimer can rule out
A high d-dimer is not diagnostic - can be high in DVT,PE, pneumonia, malignancy, heart failure, surgery, pregnancy.

Question 22

How should unprovoked DVTs be investigated?

Answer 22

Check for cancer - look at baseline bloods, physical exam, prev. recommended CXR and CT-abdopelvis
Test for antiphospholipid syndrome (antiphospholipid antibodies), hereditary thrombophilias (esp if 1st degree rel affected).

Question 23

What surgical procedure may be offered if a patient has a recurrent DVT?

Answer 23

Inferior vena cava filters
Prevent blood clots from travelling from venous system into heart/lungs/brain.
Used with recurrent PEs or those unsuitable for anticoagulation.

Question 24

What is the key epideimiology of a PE?

Answer 24

Peak 40-50yrs
Less common than ACS, pericarditis, asthma attack
More common than Pulmonary HTN, aortic dissection.

Question 25

What are the risk factors for DVT/PE according to Virchows triad?

Answer 25

Stasis/abnormal blood flow
Endothelial injury
Hypercoagulability.

Question 26

What is the relevant pathophysiology of a PE?

Answer 26

Often form embolisation of a DVT
Emboli pass through right side of heart, lodged in pulmonary arterial system, obstructing blood flow.
Increase in pulmonary vascular resistance, causing hypoxia, ischemia and inflammation in the affected lung parenchyma (SOB and pleuritic chest pain), leads to hyperventiation - hypoxemia and respiratory alkalosis.
Inc RV pressure - right sided heart failure, reduced blood flow to LV - red SV, CO and BP.
Reduced oxygenated blood to peripheral tissue.

Question 27

How will a PE show on an ECG?

Answer 27

Sinus tachy,
RVstrain V1-V4 inverted T wave
S1Q3T3 - deep s, Deep Q and inverted T

Question 28

What is the gold standard investigation for a suspected PE?

Answer 28

CT pulmonary angiogram

Question 29

What is the purpose and interpretation of a Wells Score for a PE?

Answer 29

Purpose: objectifies the risk of PE

Question 30

How to calculate the wells score for a PE?

Answer 30

Plus three: clinical s/s of DVT +/or PE most likely.
Plus 1.5: HR>100, Immobilisation for last 3 days, previous PE?DVT
Plus 1 for: hemoptysis, malignancy
Two level system: score above 4 indicates a PE is likely CTPA should be arranged.

Question 31

What is the relevant diagnostic pathway for PE based on two level wells score?

Answer 31

More than 4 - admit to hospital for CTPA immediately, if not immediate offer intermin thereapuetic anticoag
Less than 4 - D dimer within 4hrs, if pos CTPA and intermin therapeutic.