Chronic cough and Dyspnoea

Question 1

What are the causes of respiratory acidosis?

Answer 1

1. Pulmonary diseases: COPD, pulmonary fibrosis, pulmonary oedema, pneumonia, ARDS
2. Restricted lung expansion: pneumothorax, pleural effusion, haemothorax, diaphragmatic paralysis
3. Thoracic cage limitation: kyphoscoliosis, flail chest
4. Neuromuscular disorders: GBS, myasthenia gravis, polio
5. CNS depression: brainstem stroke
6. Drugs: sedatives, anaesthetics, opiates

Question 2

What is the definition of COPD in terms of duration of chronic cough?

Answer 2

COPD = chronic cough for more than 3 months (on most days) for more than 2 years

Question 3

When is a sputum gram stain and culture useful? Why is it otherwise not useful in infective exacerbations COPD?

Answer 3

Use sputum culture and gram stain when patient has risk factors for pseudomonas infection (recent hospital stay, severe COPD, previous and recent antiobiotics or glucocorticoids use)

Sputum cultures are unreliable in major of COPD infective exacerbations

Question 4

A positive urine dipstick test (for any of blood, protein, sugar) should be followed by which investigation? Why? To detect what diseases?

Answer 4

Positive dipstick test should be followed by urine microscopy to look for red cells and red cells casts, to exclude haemoglobinuria and myoglobinuria (although quite rare).

Question 5

What are the signs of heart failure on ECG in a patient with dyspnoea?

Answer 5

1. Hypertrophy
2. Ischemia
3. Arrhythmia (rhythm abnormality)
4. Conduction abnormality

Question 6

What are the causes of breathlessness? (General)

Answer 6

1. Obesity, lack of physical fitness
2. Heart failure
3. Lung disease
4. Anaemia
5. Neuromuscular & chest wall disorders

Question 7

What are ECG signs of chronic lung disease?

Answer 7

1. RVH - Deep S waves in V6, RAD,

2. RAH - Peaked S waves, esp. in V1 and V2

Question 8

What investigations should be ordered in a patient with likely exacerbation of COPD?

Answer 8

1. FBC / UEC / LFTs
2. Pulse oximetry, ABG
3. CXR
4. PEF, spirometry, lung function tests
5. Blood culture, sputum M/C/S, cytology, acid fast stain
6. ECG, Trop, CK-MB

Question 9

Why is it not sufficient to stop at a diagnosis of infective exacerbation of COPD?

Answer 9

The patient may have other co-existing new conditions like lung cancer, for which smoking is also a risk factor for.

Question 10

In investigating a patient with dyspnoea (likely infective exac of COPD), how does finding blood cells from sputum M/C/S change your differential?

Answer 10

It means that the patient could also have TB or lung cancer.

Question 11

What does polycythemia in a patient presenting with dyspnoea tell you?

Answer 11

This patient has had prolonged hypoxemia leading to increased RBCs, potentially due to COPD.

Question 12

What do you expect to see on a FBC of a patient who presents with infective exac of COPD?

Answer 12

1. Polycythemia (hypoxemia)

2. Neutrophilia (infection)