Pulmonary embolism

Question 1

List 9 non-modifiable risk factors for PE

Answer 1

DVT
Recent surgery
Immobility
Previous DVT/ PE
Malignancy
Anti phospholipid syndrome
Recent MI
Age
Pregnancy + 6w postpartum

Question 2

List 4 modifiable risk factors for PE

Answer 2

Long duration travel
Obesity
COCP
Smoking

Question 3

What occurs in a PE?

Answer 3

1 or more emboli (usually from clot in veins) lodges in + obstructs the pulmonary arterial system causing severe resp dysfunction

Question 4

What are 3 broad causes of PE

Answer 4

Hypercoagulability (e.g. increased platelet adhesion, thrombophilia).
Venous stasis (e.g., varicosis, immobilization)
Endothelial damage (e.g., inflammation, trauma)

Question 5

List 4 symptoms of PE

Answer 5

Dyspnoea
Pleuritic/ retrosternal chest pain
Syncope
Haemoptysis.

Question 6

List 6 signs of PE

Answer 6

Tachypnoea + Hypoxia
Crackles
Tachycardia.
Fever
Elevated JVP
Systemic hypotension + cardiogenic shock.

Question 7

What is the textbook triad of PE S/S? (only ~10% present like this)

Answer 7

Pleuritic chest pain
Dyspnoea
Haemoptysis

Question 8

What is performed to determine next steps in suspected PE?

Answer 8

Well’s Score
Low Probability ,<4: use D-dimer
High Probability > 4: required imaging (CTPA)

Question 9

What initial investigations should be performed in suspected PE?

Answer 9

ECG

CXR

Question 10

What may CXR show in PE?

Answer 10

Usually normal (r/o other ddx)
May see wedge-shaped opacification

Question 11

What may you see on an ECG in PE?

Answer 11

May be normal
Sinus tachycardia, RAD or RBBB
S1Q3T3 pattern (less common)

Question 12

Which bloods would you perform?

Answer 12

ABG: reduced PaO2, reduced PaCO2 due to hyperventilation
Thrombophilia screen

Question 13

What is the S1Q3T3 pattern?

Answer 13

S wave in lead 1
Q wave in lead 3
T-wave inversion in lead 3

Question 14

How can a PE cause RBBB on ECG?

Answer 14

Increased pressure from the lung results in RV overload, leading to poorer perfusion of the right bundle

Question 15

What is the preferred first investigation used for PE?

Answer 15

CT Pulmonary angiogram
Poor sensitivity for small emboli
VERY sensitive for medium to large emboli

Question 16

If low clinical suspicion of PE, what assessment can be used?

Answer 16

PERC (PE r/o criteria)

Question 17

What mneumonic can be used to remember the PERC criteria?

Answer 17

H- hormone use (oestrogen)
A- Age >50
D- DVT or PE hx
C- Coughing blood
L- Leg swelling disparity
O- O2 <95%
T- Tachycardia >100bpm
S- Surgery or Trauma (recent)

Question 18

What assessment tool can be used to estimate clinical probability of PE? What do the results indicate?

Answer 18

2-level Wells Score
,< 4: PE unlikely
>4: PE likely

Question 19

7 features of the 2-level Wells score

Answer 19

C- Clinical features of DVT (3)
A- Alternative dx less likely (3)
T- Tachycardia (1.5)
P- Previous DVT or PE (1.5)
I- Immobilisation >3 days (1.5)
C- Cancer (1)
H- Haemoptysis (1)

Question 20

What is the initial management of a patient with a Wells score >4?

Answer 20

Admit + immediate CTPA
(if NA immediately, anticoagulant in interim)

Question 21

If CTPA is negative in a patient with a Wells score >4, what should be performed?

Answer 21

Proximal leg vein USS

Question 22

In a patient with renal impairment and a Wells score >4, what investigation is preferred?

Answer 22

V/Q scan
(doesn’t require contrast)

Question 23

How should patients be further assessed with a Wells score of 4 or less?

Answer 23

D-dimer with results available within 4h (if >4 anticoagulate)

D-dimer +ve: CTPA
D-dimer -ve: consider alternative dx (+ stop interim anticoagulant)

Question 24

What should be offered as interim anticoagulation if appropriate?

Answer 24

Apixaban
or
Rivaroxaban
(if unsuitable- 5 days LMWH, then Dabigatran)

Question 25

What bloods should be taken when starting a patient on anticoagulation?

Answer 25

FBC
U+Es
LFTs
Clotting; PT + APTT

Question 26

What tool determines whether a patient with PE can be managed as an outpatient?

Answer 26

Pulmonary Embolism Severity Index (PESI)

Question 27

How should haemodynamically stable patients with confirmed PE be managed?

Answer 27

DOAC: Apixapan (10mg BD) or Rivaroxaban (15mg BD)

+ PESI risk assessment

Question 28

If DOACs are unsuitable, what other form of anticoagulation can be used in a confirmed PE?

Answer 28

LMWH
Followed by Dabigatran or Edoxaban
OR
LMWH
Followed by Vitamin K antagonist i.e. Warfarin

Question 29

What is the recommended management of cancer patients with PE?

Answer 29

DOACs (unless CI)

Question 30

What is the recommended management of patients with severe renal impairment and PE?

Answer 30

LMWH alone
OR
Unfractionated heparin alone
OR
LMWH or UFH followed by Warfarin

Question 31

For what duration should patients with PE be on anticoagulation?

Answer 31

Provoked: 3 months
Unprovoked: 6 months

Question 32

How are haemodynamically unstable PE patients managed?

Answer 32

UFH
Thrombolysis: Alteplase IV

Switch to DOAC after several hours on UFH post-thrombolysis

Question 33

What surgical options are available in massive PE management?

Answer 33

Embolectomy

Question 34

When are IVC filters indicated?

Answer 34

Recurrent PEs despite adequate anticoagulation or when anticoagulation is CI

Question 35

List 4 possible complications of PE

Answer 35

Death
Pulmonary infarction
Chronic thromboembolic pulmonary HTN
Right HF

Question 36

What is the prognosis for PE?

Answer 36

30% mortality in those left untreated
8% mortality with Tx
Increased risk of future thromboembolic disease

Question 37

What primary prevention measures can be taken for PE?

Answer 37

Compression stockings
DOAC/ LMWH
Good mobilisation + adequate hydration