Pulmonary embolism

Question 1

PE?

Answer 1

Occlusion of pulmonary vessels, most commonly by a thrombus that has travelled to the pulmonary vascular system from another site

Question 2

PE aetiology?

Answer 2

Thrombus 95% arise from DVT in the lower limbs

Rarely arises in the right atrium (in AF patients)

Other causes of embolus: amniotic fluid, air, fat, tumour

Question 3

PE risk factors?

Answer 3

surgical patients, immobility, obesity, OCP, heart failure, malignancy.

Question 4

PE epidemiology?

Answer 4

occur in 20% with confirmed DVT

Question 5

PE symptoms?

Answer 5

Small; may be ASYMPTOMATIC

Moderate; Sudden-onset SOB, cough, haemoptysis, pleuritic chest pain.

Large (or proximal); As above and: severe central pleuritic chest pain, shock, collapse, acute right heart failure, sudden death

Question 6

PE signs?

Answer 6

Small; often no clinical signs. There may be some tachycardia and tachypnoea

Moderate; tachypnoea, tachycardia, pleural rub, low O2 saturation (despite O2 supplementation)

Massive PE; shock, cyanosis, signs of right heart strain, raised JVP, left parasternal heave, accentuated S2 heart sound

Question 7

PE score?

Answer 7

Wells score is used to determine the best investigation. 4 or less = D-dimer. >4 = CTPA

Question 8

PE investigations?

Answer 8

Bloods, ECG, CXR, CTPA

Question 9

PE management primary prevention?

Answer 9

Compression stockings Heparin prophylaxis for those at risk Good mobilisation and adequate hydration

Question 10

PE management if haemodynamically stable?

Answer 10

O2 Anticoagulation with heparin or LMWH

Switch over to oral warfarin for at least 3 months

Maintain INR

2-3 Analgesia

Question 11

PE management if haemodynamically unstable?

Answer 11

Resuscitate

O2

IV fluids

Thrombolysis with tPA may be considered if cardiac arrest is imminent

Question 12

PE complications?

Answer 12

Death, pulmonary infarction, pulmonary hypertension, right heart failure