Emergency - Pulmonary embolism

Question 1

What is the classic triad of symptoms experienced in a PE?

How many patients with a PE experience this triad?

Answer 1

• Pleuritic chest pain
• Dyspnoea
• Haemoptysis

Experienced by 10% of patients with PE. Other common presentations are tachypnoea, crackles, tachycardia and fever.

Question 2

What scoring system can you use to rule out PE?

Answer 2

PERC (Pulmonary Embolism Rule-out Criteria)

Question 3

When is the PERC score used?

What does it tell you?

Answer 3

NICE 2020 guidelines

The PERC rule should be used when you think there is a low pre-test probability of PE, but want more reassurance that it isn’t the diagnosis.

• Can safely exclude PE without further testing if PERC score is 0.
• If >1, d-dimer test.

Question 4

When is the 2-level Wells score used?

What does it tell you?

Answer 4

Used if PE is suspected.

>4 - PE likely –> immediate CTPA / interim treatment dose anticoagulation

4 or <4 - PE unlikely –> d-dimer within 4 hrs / interim treatment dose anticoagulation

Question 5

Can a CTPA be performed in severe renal impairment?

Answer 5

V/Q scan - doesn’t require the use of contrast

Question 6

What are the classic ECG changes seen in PE?

How common is this in patients with PE?

Answer 6

S1, Q3, T3

• large S wave in lead I
• large Q wave in lead III
• inverted T wave in lead III

<20% of patients with PE have this presentation on PE

Question 7

What is the most common ECG finding in PE?

Answer 7

Sinus tachycardia

Signs of right-sided heart strain is RBBB and right axis deviation

S1Q3T3 is seen in <20% of patients

Question 8

Should a CXR be performed in patients with PE?

Answer 8

Yes - it is recommended for all patients to rule out other pathology, although CXR is typically normal in PE

Question 9

Does d-dimer have good sensitivity or specificity?

Answer 9

good sensitivity 95-98% but poor specificity

Question 10

Name 3 parameters in the 2-level Wells score.

Answer 10

Question 11

Answer 11

S1Q3T3

Question 12

What is the first-line anticoagulant for interim therapeutic anticoagulation?

Answer 12

1st line - DOAC e.g. apixaban, rivaroxaban

2nd line - LMWH followed by dapigatran or edoxaban OR LMWH followed by a vitamin K antagonist e.g warfarin

Question 13

What is the first-line therapeutic anticoagulant in a patient with active cancer?

Answer 13

Previously LMWH was recommended, the new guidelines now recommend using a DOAC, unless this is contraindicated

Question 14

What is the first line anticoagulant if renal impairment is severe?

Answer 14

if creatinine clearance <15/min then LMWH, unfractionated heparin or LMWH followed by Vitamin K antagonist e.g. warfarin

Question 15

How long should patients be on anticoagulation for following PE?

Answer 15

• Provoked - 3 months (3-6 months for active cancer)
• Unprovoked - at least 6 months, sometimes indefinitely depending on bleeding risk

Question 16

How does management differ in PE with haemodynamic instability?

Answer 16

• If hypotension is present, this suggests a massive PE with obstructive shock.
• There is increased pressure in the pulmonary vasculature and this reduces venous return to the right side of the heart. Preload is reduced and hence, cardiac output is reduced.
• First-line treatment - thrombolysis with IV alteplase/invasive intervention

Question 17

What can be considered in patients with repeat pulmonary embolisms?

Answer 17

inferior vena cava filter - work by stopping clots formed in the deep veins of the leg from moving to the pulmonary arteriees - weak evidence base but currently supported by NICE (2020)

Question 18

What should be done if the CTPA is negative for PE but there are symptoms and signs of DVT?

Answer 18

Ultrasound of the leg