Pulmonary Embolism

Question 1

What is pulmonary embolism?

Answer 1

The obstruction of the pulmonary artery or one of its branches (usually embolus from DVT, however may be other i.e. tumour, air, fat).

Question 2

How do you classify PE? (4)

Answer 2

> temporal pattern : acute, subacute, or chronic.

> haemodynamic stability

> anatomical location: saddle, lobar, segmental, subsegmental

> presence/absence of symptoms

Question 3

What are the signs and symptoms of PE? (5)

Answer 3

Cough
Pleuritic chest pain (worse on inspiration) - stabbing localised pain
Dyspnoea (difficulty breathing)
Tachypnoea (breath faster)
Tachycardia 

Cough +/- haemoptysis (cough blood)
Pleural rub

Question 4

What are the diagnostic tests of PE? (6)

Answer 4

D-dimer, ABG, ECG, CXR, CTPA, V/Q scan

Question 5

What is an ABG test?

Answer 5

Arterial Blood Gas

- needle into radial artery in wrist. look at gases.

Question 6

What is a CTPA test?

Answer 6

CT pulmonary angiogram

- detects blockages in one of the pulmonary vessels

Question 7

What is a V/Q scan?

Answer 7

ventilation perfusion scan

Question 8

What is Wells scoring?

Answer 8

Wells scoring is used in the diagnosis of PE and DVT.

Question 9

How does a DVT turn into a PE?

Answer 9

Clot in deep vein of leg > bit of clot breaks off > travels up to IVC into right side of heart > travel up pulmonary trunk > into pulmonary arteries&raquo_space;> lose blood supply to arteries (lungs) so not pick up O2 > shortness of breath sudden if big embolism in pulmonary trunk.

In patients with deep vein thrombosis or atrial fibrillation there is an increased risk of thrombus formation due to the reduced movement of blood.

Question 10

What are the 2 main methods to treat a pulmonary embolism?

Answer 10

Thrombolysis and Anticoagulation

Question 11

What is a major PE?

Answer 11

RVD (right ventricular dysfunction), central PE, biochemical marker elevation, haemodynamic instability.

Question 12

How do you treat an uncomplicated PE?

Answer 12

Heparin (dissolves clot)

Question 13

How do you treat a major PE?

Answer 13

Systemic thrombolysis, catheter embolectomy with local thrombolysis, surgical embolectomy.

Question 14

When do you take heparin to treat a PE?

Answer 14

Immediate anticoagulation with heparin.
LOW MOLECULAR WEIGHT HEPARIN e.g. enoxaparin “clexane” for period of several days whilst indirect oral anti-coagulant takes effect.

Question 15

When do you start Warfarin in treatment of PE?

Answer 15

Start immediately and dose titrated according to INR (international normalised ratio - a measure of prothrombin time).

Question 16

What is INR?

Answer 16

international normalised ratio

it is a measure of prothrombin time

Question 17

What precautions do you need to take with warfarin?

Answer 17

• precautions with drug interaction and intercurrent illness.
• needs to monitor INR
  = an increased INR is a risk of bleeding

Question 18

How long do you take warfarin for?

Answer 18

first episode of DVT = 3 months
first episode of PE = 6 months

may need longer or lifetime

Question 19

What is warfarin?

Answer 19

Warfarin is a vitamin K antagonist used to treat venous thromboembolism and pulmonary embolism.

Warfarin is an anticoagulant, as such it disrupts the coagulation cascade to reduce frequency and extent of thrombus formation.

Question 20

What are Novel Oral Anti-Coagulants (NOACs)?

Answer 20

The novel oral anticoagulants (NOACs) are a new class of anticoagulant drug. They can be used in the prevention of stroke for people with non-valvular AF and can also be used in the management of venous thromboembolism, which is when a blood clot forms in a vein.

Question 21

Name 4 different types of NOACs and state their mechanism of action.

Answer 21

Dabigatran - is a direct thrombin inhibitor.

Rivaroxaban, Apixaban and Edoxaban are direct factor Xa inhibitors

Question 22

What are the benefits and adverse effects of NOACs?

Answer 22

They require minimal monitoring.

But they do cause adverse effects through bleeding and interacts with drugs which affect haemostasis.

NOACs have no reversal agents. Warfarin can be stopped with vitamin K.
but half life is a lot less than warfarin.

Question 23

What are NOACs used for?

Answer 23

Prevention & treatment of VTE, prevention of stroke in patients with AF, prevention of adverse outcomes after acute management of ACS (rivaroxaban only).

Question 24

What prevention management techniques are available for pulmonary embolism patients? (4)

Answer 24

1. TEDS (thromboembolic deterrent stockings)
2. Calf pumps: elderly immobile - reduce venous stasis.
3. LMWH now given at all medical admissions unless good reason against.
4. Early mobilisation (after surgery)

Question 25

What does an IVC filter do?

Answer 25

inferior vena cava filters catch thrombi from deep leg veins before they go into the lungs.

• use when:
• PE with contraindication to anticoagulation
• recurrent PE despite adequate anticoagulation.

Question 26

Which scoring tooth is used to stratify risk of pulmonary embolism?

Answer 26

Wells score

Question 27

What is a first line treatment for a stable patient with newly diagnosed DVT or PE?

Answer 27

Low molecular weight heparin (LMWH)