pulmonary embolism

Question 1

What is a pulmonary embolism? What causes it?

Answer 1

blood clot (thrombus) forms in the pulmonary arteries. usually the result of a deep vein thrombosis (DVT) that developed in the legs and travelled (embolised) through the venous system and the right side of the heart to the pulmonary arteries in the lungs.

Question 2

How do PE’s cause symptoms?

Answer 2

they block the blood flow to the lung tissue and create strain on the right side of the heart

Question 3

What are the risk factors for PE’s? 9

Answer 3

1. Immobility 2. Recent surgery 3. Long haul flights 4. Pregnancy 5. Hormone therapy with oestrogen 6. Malignancy 7. Polycythaemia 8. Systemic lupus erythematosus 9. Thrombophilia

Question 4

How do PE’s present?

Answer 4

top 3 = triad chest pain - typically pleuritic dyspnoea haemoptysis tachycardia tachypnoea respiratory examination - classically the chest will be clear

Question 5

What is the PERC criteria and when is it used?

Answer 5

Used when probability of PE is low (<15%)

Question 6

What is the criteria in the wells score?

When is a PE likely?

Answer 6

Question 7

If PE is likely after Well’s what should you do?

Answer 7

Arrange a CTPA

Question 8

If PE is likely according to Well’s score but CTPA has been delayed what is the next step?

Answer 8

Start on anticoagulant - one that can be continued if positive = DOAC

Epixiban or Rivaroxoban

Question 9

If CTPA is negative what can you do?

Answer 9

consider a proximal leg vein ultrasound scan if DVT is suspected

Question 11

What is the investigations protocol for PE?

Answer 11

Question 12

When is V/Q scan preferable to CTPA?

Answer 12

If renal impairment - does not require contrast

Question 13

What should you do with D-dimer for those over 50?

Answer 13

Age adjust

Question 14

Besides D-dimer/ CTPA what other investigations are needed?

Answer 14

CXR for all - typically normal in PE

ECG

Question 15

What are ECG findings in PE?

Answer 15

S1Q3T3

Large S wave in Lead I

Large Q wave in Lead III

Inverted T wave in Lead III

Right bundle branch block and left axis deviation also associated

sinus tachycardia may be seen

Question 17

What ABG finding is seen in PE?

How does it differ from the other cause of this finding?

Answer 17

Respiratory Alkalosis

(tachycardia means they blow of C02)

one of the few causes, another being hyperventilation syndrome

Difference: 02 is low in PE

02 is high in Hyperventilation syndrome

Question 18

When is LMWH followed VKA used instead of DOAC in PE?

Answer 18

Severely impaired kidney function

Antiphospholipid syndrome

Question 19

How long should anticoagulants be continued for?

Answer 19

All patients should have 3 months

If provoked - stopped

If unprokoed or active cancer - continue to 6 months

HASBLED score can be used to assess bleeding risk

Question 20

When is thrombolysis recommended?

What does it involve?

Answer 20

When there is a massive PE leading to haemodynamic comrpomise e.g hypotension

injecting fibrinolytic med which breaks down fibrin which dissolves the clot

Question 21

When is thrombolysis used?

What is an example of a thrombolytic agen?

Answer 21

Where there is a massive PE where benefit outweighs risk (i.e bleeding)

Alteplase

streptokinase

Question 22

What may someone be offered if they have repeated PE’s despite anticoagulation?

Answer 22

IVC filter

prevent clots formed in deep vein of the legs moving to the pulmonary arteries