Pulmonary embolism

Question 1

Define:

Answer 1

Occlusion of the pulmonary vessels usually due to a thrombus that has travelled to pulmonary vasculature from another site

Question 2

Aetiology:

Answer 2

95% of thrombi arise from a DVT in the lower limbs

Other emboli causes:

• Fat
• Air
• Tumour
• Mycotic
• Parasite
• right ventricular thrombosis
• septic emboli
• amniotic fluid

Question 3

risk factors:

Answer 3

Immobility - long haul flights
Recent surgery
Obesity 
Pregnancy
Oral contraceptive pill
Previous PE
Malignancy 
Heart failure
Thromobophilia

Question 4

Symptoms:

Answer 4

depends on the site and the size

small - usually asymp

Moderate:

• sudden onset SOB
• haemoptysis
• pleuritic chest pain
• cough

Large - same as above:

• severe central pleuritic chest pain
• shock
• collapse
• acute RHF
• sudden death

recurrent PE:
-symptoms of pulmonary hypertension

Question 5

Signs:

Answer 5

Small may have no signs - tachypnea and tachycardia

Moderate:

• Pleural rub
• Tachycardia
• Tachypnea
• Low o2 stats
• pyrexia
• hypotension

Massive:

• shock
• cyanosis
• right heart strain (raised JVP, parasternal heave, accentuated S2 sound)

Recurrent:
-signs of pulmonary hypertension and right heart failure

Question 6

Investigations:

Answer 6

First carry out the well’s score.

< or = to 4 –> D-dimer (if negative then not PE if positive then CTPA)

> 4 CTPA (gold standard but poor at picking up small PE)

Bloods - ABG (low PaO2 and PaCO2), thrombophilia

CXR - will be clear but to rule out any other causes

VQ scan - this is done in pregnant women instead of CTPA (will show lung infarction)

Doppler US of lower limb to look for DVT

Echo- will show right heart strain
ECG - SINUS TACHYCARDIA + S1Q3T3 PATTERN

Question 7

Prevention:

Answer 7

Compression stocking

LMWH

Mobilisation

Question 8

Management if haemodynamically stable:

Answer 8

O2
Anticoagulation - LMWH or Rivaroxaban
Analgesia
Oral warfarin for 3 months following

Question 9

Management if haemodynamically unstable:

Answer 9

O2
Resuccitate
Fluids IV
Thrombolysis with tPA

Question 10

Surgical or radiological management:

Answer 10

Embelectomy

IVC filter

Question 11

Complications:

Answer 11

Sudden death
Pulmonary hypertension
pulmonary infarction
right heart failure

Question 12

Prognosis:

Answer 12

30% mortality if left untreated
8% with treatment
increased risk of thromboembolic disease

Question 13

Epidemiology:

Answer 13

relatively common

10-20% of DVT patients