Venous Thromboemboli ; DVT + PE

Question 1

What is a DVT?

Answer 1

Thrombus (blood clot) in deep leg vein

Question 2

Where are the 2 places a DVT can be?
How dangerous are they?
Which veins are they found in?

Answer 2

Below calf = less concerning (MC) + minor veins (ant + post tibial)

Above calf = life threading (LC) +fewer major veins (eg. Superficial femoral); occlusion here may impede distal flow

Question 3

What is a PE?

Answer 3

DVT embolises and lodges in pulmonary artery circulation

Question 4

Risk factors of DVT

Answer 4

Virchows triad
Endothelial damage - trauma, surgery, MI, Smoking
Hyper coagulability - sepsis, pregnancy, obesity, contraceptives
Venous stasis - AF, Immobility

Recent surgery, long haul travel, pregnancy, malignancy, polycythemia(raised RBC count), hormone therapy with oestrogen, thrombophilia (prone to blood clots - antiphospholipid syndrome), systemic lupus erythematosis

Question 5

Why can trauma cause endothelial damage?

Answer 5

Normally secretes anti coagulant chemicals, damaged endo can’t

Question 6

Why can venous stasis cause a DVT?

Answer 6

Typically spread out clotting factors (laminar flow)
Stasis = aggregation of clotting factors

Question 7

What is every patient admitted to hospital assessed for?

Answer 7

Risk of DVT

Question 8

What happens if you are deemed high risk for DVT?

Answer 8

Receive prophylaxis :
Low molecular weight heparin (enoxaparin)
Anti emboli compression stockings
(CI = peripheral arterial disease)

Question 9

What does PE cause?
How?

Answer 9

Cor pulmonale
Increased PVR = Increased RV strain to overcome this = increased RVH = RV fails 2^ to pulmonary artery pressure

Question 10

What is cor pulmonale?

Answer 10

Abnormal enlargement of RHS of heart due to disease of lungs or pulmonary BV

Question 11

Symptoms of a DVT

Answer 11

Unilateral swollen calf, dilated superficial veins, typically warm & oedematous

Complete occlusion of large vein =phlegmasia ceruleo dolens (severe ischemia, leg turns blue)

Question 12

What test is done to assess DVT and PE?
What does it check?

Answer 12

Wells score
Predicts risk of patient with symptoms having DVT/PE
Includes RF - recent surgery, clinics, findings (unilateral calf swelling >3cm)
Use online calculator

Question 13

What’s the wells score for DVT?

Answer 13

> 1 = likely DVT
Eg. Calf swelling 3+cm than other leg =1pt
Pitting oedema =1pt

Question 14

Symptoms of PE

Answer 14

Pleuritic chest pain (sharp pain when breathing deeply)

Dyspnoea (+/- haemoptysis) - cough up blood - streaks of blood mixed with normal sputum

With evidence of DVT eg. Swollen calf & immobilization history
-tachy, hypo, increased JVP, ankle oedema

Question 15

Wells score for PE?

Answer 15

> 4 = likely PE
Eg. Evidence of DVT = 3pt, tachy = 1.5pt

Question 16

Diagnosis of DVT

Answer 16

D dimer & duplex ultrasound (GS)
<1 = D dimer = not raised = not PE
>1 = (raised D dimer) = duplex US = DIAGNOSTIC

Question 17

What’s a D dimer test ?
How sensitive /specific is it?

Answer 17

Blood test - small protein released into blood when blood clot fibrinolysed

Sensitive -95% of patients with a DVT have increased D dimer
Not specific - many patients with increased d dimer will not have DVT
Good to exclude DVT

Question 18

Other conditions causing increased d dimer?

Answer 18

Pneumonia, malignancy, heart failure, surgery, pregnancy

Question 19

Which other diseases present with which symptom same as PE?

Answer 19

PE, pneumothorax, pneumonia all present with pleuritic chest pain

Question 20

Diagnosis of PE

Answer 20

Key - D dimer, CT pulmonary angiogram CTPA (GS)

ECG - sinus tachycardia - S1Q3T3 (pathognamonic) - major sign of cor pulmonale
-T wave inversion of anterior & inferior leads - most specific finding
- new RBBB

Chest x ray = normal

Wells:
<4 = D dimer = not raised = notPE
4+ = (raised D dimer) = CTPA = diagnostic

Question 21

How can you differentiate between PE and pneumonia + thorax?

Answer 21

Chest x ray
PE = normal
Others = diagnostic

Question 22

Treatment for DVT and non massive PE?

Answer 22

Anti coagulation (DOAC)
-Apixaban/ rivaroxaban
(Start immediately where suspected/delay in scan)

LMWH if above CI (renal impairment)
+ mobalisation + compression stockings

Question 23

Treatment for massive PE?

Answer 23

(Hypo<90)
Thrombolytics (alteplase - clot buster)

Question 24

Differential diagnosis for DVT
Difference in symptoms & test results?

Answer 24

Cellulitis = skin infection, typically staph aureus & strep pyogenes
Tender, inflamed, swollen calf with pronounced demarcation
Will show leukocytosis (indicative of infection) on blood test FBC , while DVT levels normal

D dimer and duplex us can confirm DVT