• Give your own definition of COPD.

chronic obstructive diseases describe different combinations and grades of three obstructive airway conditions, namely bronchial asthma, chronic bronchitis and emphysema.  These conditions limit pulmonary airflow and gas exchange and can therefore lower life quality by causing sleeping disorders, reducing the ability to perform physical activity and, during acute attacks, leading to fear, hypoxia and even death

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

Chronic bronchitis    

Chronic bronchitis is a non-specific obstructive airway disease of which the exact aetiology is unclear, but which is associated with long-term exposure to irritants, e.g. cigarette smoke, dust and irritating gases. The symptoms and signs of chronic bronchitis are associated with mucus hypersecretion, reduced mucociliary clearance, regular bacterial airway infections and structural changes in the bronchial walls.  Chronic bronchitis sufferers also develop a chronic cough in reaction to the excessive sticky phlegm.  Because the vagus reflex is a typical result of the stimulation of irritant receptors in the airways, an overactive parasympathetic nervous system plays an important role in chronic bronchitis.

Emphysema    

Emphysema comprises a nonreversible dilation of the respiratory bronchiole and alveoli (loss of elasticity) as a result of structural damage to the walls. The air is, therefore, caught in the respiratory space of the lungs and is exhaled with difficulty, disrupting ventilation of the lungs.  Furthermore, there is also sometimes a decrease in capillary blood vessel provision which further hampers gas exchange.  As in the case of chronic bronchitis, cigarette smoke is a very important cause, especially in heavy smokers or genetically susceptible individuals (e.g. persons with a₁-antitrypsin deficiency).

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

Smoking:

Giving up smoking is extremely important and is necessary to prevent progression.  Psychotherapy, consultation and encouragement (rather positive than cautionary), as well as support, possibly with other drugs, is important to wean the smoker.  There is however, controversy over the efficacy of nicotine-containing drugs to assist in ending the smoking habit.

Bacterial infection:

Annual prophylactic immunisation against influenza (very effective) and a single immunisation against pneumococci (less effective) can be considered.  Broad-spectrum antibiotics (tetracyclines, cotrimoxazole, amoxicillin, ampicillin or erythromycin) can, as required, be used against, especially, pneumococci and Hemophilus Influenzae.

Airflow obstruction:

Airflow obstruction can be treated by means of drugs as for bronchial asthma.  The choice of drug is, however, somewhat different, as discussed below.  The use of a mixing chamber together with aerosols and regular airflow monitoring, by means of a peak-flow meter, holds many advantages.

Secretes:

Rehydration (sufficient intake of liquids) and regular steaming (e.g. humidifier at night) dilutes the mucus and promotes mucus clearance.

Hypoxia:

The morbidity and mortality in serious grades of COPD improve drastically with 18-24 hours/day O₂ inhalation therapy. It is therefore strongly recommended in cases of continued hypoxia (various types of portable O₂ containers are available).  Some patients require O₂ inhalation therapy only with exercise or during sleep.

Weak lung capacities:

Mild and regular exercise improves lung capacities and life quality but must be done with caution where there are already heart complications.

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

Although the inhalation of b₂-sympathomimetics is effective to counteract bronchial constriction and it possibly improves mucociliary clearance, anticholinergic therapy (ipratropium inhalation) is currently favoured as a first-line drug for the treatment of COPD. Specifically, with COPD (chronic bronchitis and emphysema) the bronchodilatory effect is usually better than what is achieved with b₂‑sympathomimetics.  This can be understood, especially in the light of the role of the parasympathetic nervous system in chronic bronchitis, as discussed above. 

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

    Theophylline has the special advantage that it improves diaphragm contractility and reduces diaphragm exhaustion, improves cardiac contractility, lowers pulmonal resistance, improves mucociliary clearance and improves the ventilatory response.

• What is the role of oxygen therapy in COPD?

If the combination of ipratropium, a b₂-sympathomimetic and theophylline does not provide enough relief, inhalation or oral administration of corticosteroids can be tried.  The corticosteroids are however, mostly ineffective, but a few patients react within two weeks.  If necessary, oxygen therapy must be applied.