• Give your own definition of COPD.

COPD consist of different degrees and combinations of bronchial asthma, chronic bronchitis and emphysema.

• Briefly describe the proposed aetiology and pathophysiology of chronic bronchitis and emphysema.

Chronic bronchitis:

Aetiology is unknown (idiopathic).

It is a non-specific obstructive disease where there are an increase in mucus production/secretion and a decrease in mucus clearance. The bronchial walls undergo structural changes, frequent respiratory bacterial infections occur and a chronic cough due to sticky mucous occur.

Emphysema:

Aetiology is smoking, irritants and those who are susceptible because of an alpha 1 antitrypsin deficiency.

It is the irreversible dilation of respiratory bronchioles and alveoli due to structural changes. Air gets trapped in the lungs and are exhaled with difficulty. There are also a decrease in capillary blood vessels which further impedes gas exchange.

• Which types of therapy are included in the treatment of a COPD patient?

Anticholinergics: Ipratropium and tiotropium (or long acting: glycopyronium bromide)

Bete 2 stimulants and/or slow release theophylline

Corticosteroids sometime used but not usually well tolerated

Oxygen therapy

Acute illness: hospitalization, antibiotics, physiotherrapy

Cessation of smoking

Bacterial infections: yearly influenza immunization or broad spectrum antibiotics (tetracyclines, ampicillin, amoxicillin, erythromycin, cotrimoxazole)

• Why is ipratropium more effective in the treatment of chronic bronchitis than in the treatment of bronchial asthma?

Chronic bronchitis is due to irritants that stimulate the vagus reflex which cause an overactive parasympathetic nervous system while asthma is due to sympathetic and parasympathetic effects. Ipratropium which is an anticholinergic drug and parasympatholytic will thus be more effective in bronchitis and not in bronchial asthma as although some effect will be seen because of inhibition of the parasympathetic nerve system, the sympathetic nervous sytem will be unopposed thus asthma symptoms will not be entirely reduced by ipratropium.

• In which way do the skeletal muscle effects of theophylline have advantages in the treatment of COPD?

It strengthens the contraction of diaphragm skeletal muscles which improves the ventilation response/ventilation capacity, reduce the hypoxia and reduce the dyspnea associated with COPD.

• What is the role of oxygen therapy in COPD?

It reduce the symptom of hypoxia associated with COPD.