COPD

Question 1

define COPD

Answer 1

progressive obstructive pulmonary disease that is not fully reversible

• associated with abnormal inflammatory response of the lung to noxious particles or gases

Question 2

what are the disease subsets within COPD?

Answer 2

chronic bronchitis and emphysema

chronic bronchitis = chronic productive cough for three months in a patient whom other causes of a chronic cough have been excluded

emphysema= abnormal and permanent enlargment of the airspaces that are distal to the terminal bronchioles accompanied by destruction of airspace walls without obvious fibrosis

Question 3

what is the pathophysiology of COPD?

Answer 3

in COPD airway inflammation leads to a thickened and distorted alveolar wall/septum and loss of attachments- therefore they no longer effectively maintain an open air space = obstructed flow by air trapping

also, you get loss of cross sectional surface area fro gas defusion

Question 4

What findings will we see on a spirometry in a COPD patient?

Answer 4

• decreased FEV1
• Decreased Total FVC
• Decreased FEV1/FVC ratio
  *

Question 5

how does COPD compare to asthma?

Answer 5

• Both: associated with CD8+ T lymphocytes, neutrophils and CD68 monocytes/macrophages
• asthma: effects patients of all ages, associated with CD4 T lymph, eosinophils and increased IL4,5
• COPD: manifest later in life and have higher mortality

Question 6

how do we diagnose COPD?

Answer 6

• history: cough, sputum, dyspnoea, wheeze, acut exacerbation
• examination: central cyanosis, chest hyperinflation/reduced expansion, increased resonance, reduced breath sounds, end-expiratory wheeze, signs of RVfailure, indrawing of intercostals, use of accessory muscles, diminished breath sounds
• Investigations: Spirometry with reversibility testing to rule out asthma and carbon monoxide diffusion studies, CXR is NOT necessary for diagnosis but you would see flattening of diaphragm, CT is greatest sensitivity for detecting emphysema

Question 7

under what condition do we give oxygen to COPD patients?

Answer 7

we only give it to those who are hypoxic at baseline

we give very little- b/c there is a risk of reducing their hypoxic drive = respiratory arrest

Question 8

what drugs do we generally use in the treatment of COPD?

Answer 8

• SABA
• SAMANT
• LABA
• LAMANT
• ICS

Question 9

What are the symptoms of COPD?

Answer 9

progressive, persistent and ‘worse with exercise’ dyspnoea

chronic cough

chronic sputum produciton

Question 10

what classification do we use to categorize severity of airflow limitation in COPD?

Answer 10

1. GOLD 1 (mild) = FEV1 > 80%
2. GOLD 2 (moderate)= 50%< FEV1< 80%
3. GOLD 3 (severe)= 30% < FEV1< 50%
4. GOLD 4 (very severe) = FEV1< 30% predicted

Question 11

what are our steps for assessments of COPD patients?

Answer 11

1. assess symptoms
2. assess degree of airflow limitation using spirometry
3. assess risk of exacerbations

Question 12

How do our medications for COPD correlate with the staging of disease?

Answer 12

worst case = ICS + LABA + LAMAnt

best case = SAMAnt prn or SABA prn

Question 13

under what conditions do we prescribe long term oxygen therapy for COPD patients?

Answer 13

with chronic hypoxemia = PaO2< 7.3 kPA

or

Chronic hypoxemia = PaO2< 8kPA if there is evidence of corpulmonale, noctural desaturation , or pulmonary hypertension

*there is no benefit if PaO2> 8kPA