COPD

Question 1

How does chronic bronchitis limit airflow?

Answer 1

• inflam process → ↑ mucus production → airway obstruction
• damage to endothelium → mucus gland hyperplasia, impairs mucociliary response to clear mucus and bacteria
• results in airway deformation and narrowing of lumen → limiting airflow

Question 2

Clinical definition of chronic bronchitis

Answer 2

productive cough for > 3 months each year for 2+ consecutive years

Question 3

Describe the physiology of impaired gas exhange in emphysema

Answer 3

• ↑ elastase production → excess destruction to alveolar wall → loss of elastic recoil equals airflow limitation → airways collapse when breathing out → air becomes trapped in alveoli → bullae formation → alveoli fusion

This leads to loss of alveolar support structure → airway narrowing → gas exchange impaired → hypoxia, co2 retention - elastases - destroy elastin and alveolar wall and respiratory bronchioles
- anti-elastases: stop elastase

Question 4

COPD Complications (CLIPPeR)

Answer 4

Cor pulmonale
Lung cancer
Infections - give macrolide abx
Pneumothorax
Polycythaemia
e
Resp failure (type II)

Question 5

How can COPD cause type II resp failure?

Answer 5

Significant V/Q mismatching with a relative increase in the physiological dead space leads to hypercapnia and hence acidosis