SOB Differentials

Question 1

Pathophysiology of most presentations

Answer 1

Cardiopulmonary

Non cardiopulmonary

• anxiety, neurogenic causes => hyperventilation
• acidosis (DKA, AKI)
• impaired O2 delivery (sickle cell, CO poisoning)
• muscle weakness

Question 2

Pattern of presentation

Answer 2

Circumstances - COVID, trauma
PHx - COPD, asthma, HF
Other symptoms - chest pain
Onset - acute, subacute

Question 3

Common diagnoses

Answer 3

Asthma - past episodes, characteristic symptoms
COPD exacerbation - smoking Hx, chronic symptoms
HF - characteristic symptoms
Pneumonia - normally subacute
PE - non specific symptoms
PT - trauma
Blood loss - trauma, GI symptoms

Question 4

Less common diagnoses

Answer 4

Arrythmias - AF can precipitate HF
Pulmonary edema from non HF causes
Upper airway obstruction
Anemia
CO poisoning
Hemothorax
Cardiac tamponade
Non-cardiopulmonary
-anxiety
-acidosis
-thyrotoxicosis
-muscular weakness

Question 5

Differentiating between HF and COPD

Answer 5

HF

• ankle swelling
• high JVP
• S3
• inspiratory creps

COPD
-sputum production

Question 6

Investigations

Answer 6

Immediate assessment - Hx, exam, NEWS

O2 if hypoxic

Venous access

• FBC - anemia, infection
• U&E - renal function, electrolytes disturbance
• CRP
• routine bloods - LFTs, glucose
• Troponin, BNP, DD

ABG - esp in COPD
ECG
CXR
Specialised imaging - CTPA, echo (for pericardial effusion)

Question 7

Common causes of chronic breathlessness

Answer 7

More lung based

• COPD
• asthma
• pulmonary fibrosis
• anemia
• pulmpnary HTN

Question 8

MOST COMMON ACUTE PRESENTATIONS

Answer 8

ASTHMA
COPD
HF