PE

Question 1

Define it

Answer 1

A thrombus which embolises to the lungs via the inferior vena cava and occludes the pulmonary vasculature

Question 2

Risk factors

Answer 2

• Age
• DVT
• Recent surgery
• Bed rest
• Malignancy
• Pregnancy
• COCP
• Antiphospholipid syndrome - puts the patient at an increased risk of thrombosis by increasing coagulability

Question 3

CF

Answer 3

Sudden pleuritic chest pain (sharp chest pain when breathing deeply) - aggravated by coughing swallowing or deep inspiration

Dyspnoea
Tachycardia and tachypnoea esp in absence of any respiratory
Signs of DVT- unilateral painful leg swelling

Question 4

What is the most appropriate initial investigation for suspected PE?

Answer 4

CXR- sometimes it would normal (or sometimes wedge shaped opacification)
This is used to rule out other causes of chest pain e.g. pneumothorax

Question 5

What is the preferred investigation for definitive confirmation

Answer 5

CT pulmonary angiography with wells score > 4.
Wells PE score is used to evaluate a patient with suspected PE to establish the probability that it is likely

Question 6

What do we do for haemodynamically unstable patients who can’t have CTPA?

Answer 6

Echocardiography

Question 7

What do we do whilst waiting for results of CTPA for suspected PE

Answer 7

Start DOAC

Question 8

What do you do if CTPA negative but still suspect PE?

Answer 8

Proximal leg vein US if DVT suspected

Question 9

When is V/Q scan preferred and what does it do

Answer 9

VQ scan is a non-invasive, two part nuclear medicine test that evaluates airflow (ventilation) and blood flow (perfusion) in the lungs
It identifies areas of ventilation and perfusion mismatch, indicating area of infarcted lung

• renal impairment
• contrast allergy
• pregnant

Question 10

In what case do you do a D-dimer?

Answer 10

Wells score ≤4 for non-pregnant patients (it’s more sensitive than CTPA too)

If d dimer is raised, do CT pulmonary angiogram
If d dimer is negative, consider alternative diagnosis and stop anticoagulation if you have put them on it in the meantime

Question 11

What would ECG show

Answer 11

• Sinus tachycardia → main one
• S1Q3T3 → textbook but rarely seen
  
  • S wave in lead I, Q waves in lead III, inverted T waves in lead III

Question 12

What could an echo show in a large PE?

Answer 12

Right ventricular dilatation → a big PE would increase afterload on RV which can cause dilatation since the mechanical obstruction of the pulmonary arteries and reflex-mediated pulmonary vasoconstriction

Question 13

What is the initial management for haemodynamically stable patients

Answer 13

DOAC (Apixaban or Rivaroxaban)

Question 14

How long do you continue medication if it is a provoked PE?

Answer 14

Provoked- things like after surgery. PE usually caused by a known event

3 months

Question 15

How long do you continue medication if it is a unprovoked PE?

Answer 15

6 months

Question 16

What can you prescribe if DOAC’s are contraindicated?

Answer 16

Use warfarin

Question 17

What is the target INR for recurrent PE?

Answer 17

3.5

Question 18

What management if pregnant

Answer 18

LMWH instead of DOAC

Question 19

What is the management for haemodynamically unstable patient (<90 mmHg)?

Answer 19

Thrombolysis (Alteplase) + unfractionated heparin

Question 20

What is mortality often due to?

Answer 20

Cardiogenic chock secondary to right ventricular collapse