CBL 5: A Patient with Breathlessness

Question 1

What are the differential diagnoses you may consider based on the given
history alone?

Answer 1

Pneumonia
Hypertension
Pleuritis
ACS

Question 2

How does a PE present?

Answer 2

Haemoptysis
Dyspnoea — this is the most common feature and is present in 50% of people with PE
Pleuritic chest pain — present in 39% of people with PE; Pain is normally localised to one side.
Cough — present in approximately 23% of people with PE.
Syncope or pre-syncope
Tachypnoea — present in 21-39% of people with PE.
Features of deep vein thrombosis (DVT)
Retrosternal chest pain (due to right ventricular ischaemia).

Question 3

Describe the heart sound often occurs in PE [1]

Answer 3

Gallop rhythm, a wide split-second heart sound, tricuspid regurgitant murmur.

Question 4

How does ACS present differently in females? [1]

Answer 4

Present atypically:
- epigastric or back pain or pain that is described as burning, stabbing, or characteristic of indigestion

Question 5

Which populations present atypically with ACS? [2]

Answer 5

Women
Diabetes patients

Question 6

Q4. Identify the terms you would like to learn about and to discuss.
Q5. What is your interpretation of the given signs?
Q6. What are the main priorities of management now?

Answer 6

ABCDE
A:
- Given she’s talking, her airways are fine

B:
- She has high resp. rate
- Give 15L oxygen
- Examine the chest for breath sounds: see if equal chest expansion, percuss and listen to breath sounds

C:
- PC: Tachycardia, central cyanosis, hypotensive
- Give 500ml 0.9% NaCl STAT (less than 15mins)
- (Stop amlodopine anti-hypertensives for acute attack)

D:
- Leg swollen - check for pitting oedema
- Check GCS
- Check blood glucose (i.e. for DKA - probably not for this case, but need to consider)
- Temperature

E
- Leg swollen, squeeze calf - see it patient complains [? why]
- Check pulses

Question 8

What type of shock is the patient potentially in?

Answer 8

Obstructive shock

Question 9

This patient is haemodynamically unstable. What does this mean? [1]

Answer 9

SBP < 90 mmHg

Question 10

Q8. Which specific investigations are indicated and useful?

Answer 10

CXR:
- Want to exclude pneumothorax and other pathologies

CTPA

Question 11

What is the management plan if you suspect a PE but the Wells Score < 4? [2]

Answer 11

Offer a D-dimer test with the result available within 4 hours

If the D-dimer test is positive:
arrange admission to hospital for an immediate CTPA and, where necessary, other investigations

If the D-dimer test is negative
- Stop interim therapeutic anticoagulation (if appropriate).
- Advise the person that it is not likely that they have a PE, but discuss the signs and symptoms, and when they should seek further medical help.
- Consider an alternative diagnosis.

Question 12

Q7. What specific medication(s) you may administer before the investigations
being done?

Answer 12

Administer:
- IV Alteplase: anti-fibrinolytic. Preferred because shes haemodynamically unstable

Question 13

Name 4 other pathologies that can cause raised D Dimer? [5]

Answer 13

Pneumonia
Malignancy
Heart failure
Surgery
Pregnancy

Question 14

What do you do if want a CTPA because you suspect a PE, but it takes ages to occur? [1]

Answer 14

Start treatment

Question 15

There are three imaging options for establishing a diagnosis of a pulmonary embolism [3]

Answer 15

There are three imaging options for establishing a diagnosis of a pulmonary embolism:

CT pulmonary angiogram (the usual first-line)

Ventilation-perfusion single photon emission computed tomography (V/Q SPECT) scan:
- Ventilation-perfusion (VQ) scan involves using radioactive isotopes and a gamma camera to compare ventilation with the perfusion of the lungs.
- First, the isotopes are inhaled to fill the lungs, and a picture is taken to demonstrate ventilation
- Next, a contrast containing isotopes is injected, and a picture is taken to illustrate perfusion
- The two images are compared.
- With a pulmonary embolism, there will be a deficit in perfusion as the thrombus blocks blood flow to the lung tissue. The lung tissue will be ventilated but not perfused

Planar ventilation–perfusion (VQ) scan

Question 16

How long does a DOAC take to work? [1]

Answer 16

Few days

Question 17

How long does warfarin take to work? [1]

Answer 17

5 days

Question 18

Which differential diagnoses are you trying to rule out on CXR with PE? [3]

Answer 18

Pneumothorax
Pleural effusions
Pneumonia

Question 19

Answer 19

Sinus tachycardia

Question 20

What is the rate in this ECG? [1]
Why is this calculation important? [1]

Answer 20

300/2.5 = 120

Because sinus: rules out afib

Question 21

Why do you get sinus tachycardia in PE?

Question 22

What ECGs indicate a patient is suffering from PE? [2]

Answer 22

Sinus tachycardia is a very common finding in PE

S1: deep S waves in S1
Q3: deep Q waves in lead 3
T3: T wave inversion in lead 3

Question 23

How do you acutely treat PE in a patient who is suspected to be suffering from PE and is haemodynamically stable? [3]

Answer 23

Acutely:
- 15 L oxygen
- Consider 500ml saline over 15-30mins (STAT) if SBP < 90 and JVP is elevated
- apixaban or rivaroxaban (DOAC)
- LMWH is alternative

Question 24

How do you acutely treat PE in a patient who is confirmed (on echocardiography or CTPA); haemodynamically unstable? [5]

Answer 24

Acutely:
- Thrombolysis: alteplase; streptokinase; urokinase
- Start on heparin
- apixaban or rivaroxaban
- 15 L oxygen
- Consider: noradrenaline or dobutamine: as a vasoactive drug if SBP remains < 90
- Consider: surgical embolectomy/percutaneous catheter-directed treatment if thrombolysis fails

Question 25

How do you long term treat PE? [3]

Answer 25

Give apixaban, rivaroxaban, edoxaban and dabigatran for 3 months

Question 26

Which patient populations would you give LMWH instead of a DOAC in a suspected PE? [1]

Answer 26

Use a weight-adjusted dose of LMWH in women who are (or may be) pregnant.

Active cancer patients

Question 27

Which groups of patients would you have longer (3-6 months) DOAC treatment for that 3months post PE? [1]

Answer 27

Active cancer: give 6 months of DOAC

Question 28

What drug choice is used for long term treatment of PE in pregnant population [1] and how long for? [1]

Answer 28

In pregnant patients, continue LMWH for the remainder of the pregnancy and for at least 6 weeks postnatally and until at least 3 months of treatment has been given in total

Question 29

WQ16. What is the underlying pathophysiology of this condition?

Answer 29

Virchow’s triad:

1.Vessel wall damage:
- endothelial cell damage promotes thrombus formation, usually at the venous valves
- Damage to the vessel wall can occur after a number of insults including trauma, previous DVT, surgery, venous harvest, and central venous catheterisation

2. Venous stasis:
   - poor blood flow and stasis promote the formation of thrombi.
   - Venous stasis and congestion result in valvular damage, further promoting thrombus formation. Increased venous stasis
   s associated with age >40 years, immobility, general anaesthesia, paralysis, spinal cord injury, myocardial infarction, prior stroke, varicose veins, advanced congestive heart failure, and advanced COPD.
3. Hypercoagulability:
   - Causes include cancer, high-oestrogen states (oral contraceptives, hormone replacement, obesity,
   pregnancy), inflammatory bowel disease, nephrotic syndrome, sepsis, blood transfusion, and inherited
   thrombophilia (factor V Leiden mutation, prothrombin gene mutation, protein C and S deficiency, antithrombin deficiency, and antiphospholipid antibody syndrome).

Question 30

Which medications increase the liklihood of PE?

Answer 30

Contraceptive pills
Hormone replacement therapy

Question 31

Why does the combined pill increase likilihood of blood clots? [1]

Answer 31

Increased oestrogen causes hypercoagulability

Question 32

Which patient populations are more at risk of PE? [5]

Answer 32

Suffer from DVT
Recent surgery
Significant immobility
Pregnant women
Active cancer
Recent MI
Antiphospholipid antibody syndrome
Recent trauma

Question 33

The leading cause of death in patients with high-risk (massive) PE is acute [1]

Answer 33

The leading cause of death in patients with high-risk (massive) PE is acute right ventricular (RV) failure with resulting hypotension

Question 34

Explain what ABG would present like for a PE patient? [3]

Answer 34

Patients with a pulmonary embolism often have respiratory alkalosis on an ABG.

Hypoxia causes a raised respiratory rate.

Breathing fast means they “blow off” extra CO2.

A low CO2 means the blood becomes alkalotic.

Question 35

Name differential diagnosis to PE that would cause respiratory alkalosis [1]

How would you distinguish between the two? [1]

Answer 35

The other main cause of respiratory alkalosis is hyperventilation syndrome

• Patients with PE will have a low pO2
• Patients with hyperventilation syndrome will have a high pO2.

Question 36

Why does BP fall in PE ? [1]

Answer 36

Causes obstructive shock

Question 37

What is the MoA of warfarin? [1]

What is the INR targer for warfarin when treating DVTs and PEs? [1]

Answer 37

Warfarin is a vitamin K antagonist.

The target INR for warfarin is between 2 and 3 when treating DVTs and PEs.

Question 38

What pathology would contraindicate anti-embolic compression stockings for PE / VTE [1]

Answer 38

Anti-embolic compression stockings are also used unless contraindicated (e.g., peripheral arterial disease).

Question 39

Why would CTPA be contraindicated when investigating PE? [1]

Answer 39

Kidney damage; contrast toxicity