Chronic obstructive pulmonary disease, or COPD, is so named because these disease processes trap air in the lungs. These pulmonary diseases range from emphysema to asthma and chronic bronchitis. Each disease traps air in the lings by a different mechanism, but air trapping is common to them all.

In emphysema, the lungs loose their elasticity such that they become like an over blown balloon that doesn't snap back into its original shape. These overly large air sacks can become quite large and crowd out the more normal airways. This is why surgery is sometimes very effective in relieving some of the symptoms associated with emphysema.

In asthma, the small and medium size airways constrict, which produces trapped air in the lungs. The airways of the asthmatic are often overly sensitive to temperature changes and allergens. Drugs such as beta-2-adrenergic agonists and corticosteroids are most commonly used to relax constricted airways and reduce or prevent inflammation.

In chronic bronchitis, the larger bronchial airways are often infected and inflamed, which triggers the production of excess secretions. As these larger airways become blocked with excess secretions, this traps air within the lungs. This is often treated with antibiotics, beta-2-adrenergic agonist drugs and postural drainage in order to assist the lungs in removing excess secretions that build-up and block the airways in chronic bronchitis.

When air is trapped in the lungs, the normal exchange of fresh air into and out of the lungs is disrupted. This produces a change in the ability of the lungs to absorb oxygen and eliminate carbon dioxide. Because it is essential that the cells within our bodies take in oxygen and eliminate carbon dioxide as a waste by product in order to run our metabolism, our lungs must work effectively to perform this vital function. The arterial blood gases, also called ABGs, determine how well our lungs provide us with oxygen and eliminate the carbon dioxide within our bodies. Too much trapped air may reduce both oxygen uptake and carbon dioxide elimination. This in turn, may affect the amounts of these gases in our blood.

Because these are chronic diseases, there may be many years of disease before there are large changes in the ABGs or blood gases. However, if someone with COPD becomes suddenly ill with the flu or a cold, they may experience a sudden change in their lung function because they don't have the pulmonary reserve that people with normal lungs have. This can trigger a trip to the emergency room and a stay in the hospital. However, by knowing the basic disease mechanisms associate with COPD diseases, a person can reduce their chances of triggering attacks that exacerbate their condition.

Often changes in a person's exercise, diet and life style will greatly improve their lives and reduce the incidence of sudden attacks. Breathing techniques such as pursed lip breathing and measuring one's expiratory volume with a flow meter can give a person more control over their symptoms. Consulting with their doctor, therapist or nurse can help people with COPD to lead happy, productive and near normal lives.

Learn more about this author, Richard G. Lanzara.
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