Chronic obstructive pulmonary disease – COPD
Chronic obstructive pulmonary disease (COPD) epresents a disorder characterized by permanent narrowing of the lower (i.e., intrapulmonary) airways. In contrast with asthma, the narrowing is irreversible, and over time, it shows relentless progress. COPD is one of the most significant contributors to mortality, worldwide. It afflicts 300 million people all over the world, with an annual death toll of 3 millions; therefore, it is the third most frequent cause of death. Potentially every 20th person may suffer from it, 15% of the smokers and 26% of the population above 45. In Hungary, according to the data of the National Korányi Institute of Tuberculosis and Pulmonology, the number of patients who are registered in the system of pulmonary rehabilitation centers because their serious disease requires regular treatment reached 168,431 in 2014. However, the actual figure may amount to 400 000–500 000.
In the development of COPD, the most important contributing factor is smoking. Permanent inhalation of cigarette smoke and other harmful types of smoke results in the inflammation of the bronchial system, destruction of lung parenchyma and fusion of the alveoli. This decreases the available respiratory surface and leads to over-inflation (emphysema) of the lungs. The hallmark of the process is dyspnoea, which can be provoked by less and less exertion, lasts longer and longer and can even be experienced at rest. The disease also affects non-smokers but at a much lower rate (5-10% of the total number of COPD cases). Frequent respiratory infections experienced in childhood also increase the susceptibility to the development of COPD.
Dyspnoea of increasing severity, chronic and productive cough (i.e., chronic bronchitis), and physical disability all have a great negative impact on the patients' daily activity and quality of life.
The most important symptoms of COPD:
- fatigue, exhaustion developing soon upon exertion,
- dyspnoea after walking only few stairs,
- less stamina compared to peers,
- regular morning coughs,
- reduced activity in everyday life, and
- decreased capability of performing regular daily activities.
To establish the correct diagnosis, the detailed knowledge on the following points of the patient's history are indispensable: the onset, frequency and characteristics (presence of wheezing) of cough, the patient's habits, history of smoking, and severity of dyspnoea.
The next step of investigation is physical examination, which focuses on the auscultation of respiratory sounds. Emphysema causes observable symptoms only in severe cases. Radiographic changes are of diagnostic value only in serious cases (destruction of the alveoli results in characteristic loss of tissue). The most important routine method of examination is spirometry (pulmonary function test), which can measure different physical parameters of respiration, and this way, the narrowing of the airways can be established. The most significant value is that of FEV1, which equals the volume exhaled during one second of forced expiration. Cigarette smoke causes derangements years before the onset of the symptoms of the disease, which can be demonstrated by regular pulmonary function tests performed every 3 to 5 years. If the drop in FEV1 exceeds the annually expected 25 to 30 mL, it may reflect on the development of chronic obstructive bronchitis. The examination is of crucial importance, as COPD begins insidiously. Dyspnoea upon mild exertion may indicate an advanced stage of the disease. If the patient's exhalation lasts longer than 5 seconds, and simultaneously, wheezing can be heard on auscultation, COPD is the probable diagnosis.
At present, COPD is considered to be an incurable disease; however, the symptoms and the consequences of its complications can be mitigated, and the patients' quality of life can be improved. The most widespread therapeutic options in the treatment of the disease are the following:
Bronchodilators relax the smooth muscles, which surround the airways, thus decreasing cough and dyspnoea, and alleviating breathing.
Inhaled steroids relieve respiration by reducing airway inflammation.
Antibiotics are useful in COPD sufferers who have primary symptoms aggravated by additional respiratory diseases, such as pneumonia.
Oxygen therapy may be useful when the oxygen saturation levels in the blood are not sufficient.
The hallmarks of worsening in the progress of obstructive bronchitis and emphysema are more frequent bouts of dyspnoea, more intense coughing fits, accumulation of phlegm, and gradual decrease in stamina. The most frequent complications are various infections of bronchi as well as pneumonia. Further deterioration can be brought about by inhalation of polluted air and diseases of the cardiopulmonary system.
Simple bronchitis responds well to therapy, but after its progress into an obstructive form, definitive treatment is not possible any longer. Nevertheless, by the cessation of the inhalation of toxic compounds, e.g., the patient quits smoking, the relentless progress can be halted.
Accordingly, the tissue damage evoked by emphysema cannot be reversed either, the lost alveoli cannot regenerate, and the spirometric values cannot return to normal. But after the cessation of smoking, the expected further changes are similar to those who never smoked.
