the alveoli become inflamed and filled with fluid and the air spaces in the alveoli become
filled with blood and fluid. As you might expect, the exchange of gases in the alveoli
becomes impaired. Death can result from pneumonia.
Asthma, a condition usually caused by allergic reactions to substances in the
environment, affects many people. The allergic reactions cause the bronchioles to
spasm. Hence, the flow of air into and out of the lungs becomes impaired. For some
unknown reason, the flow of air out of the lungs is more impeded than the flow of air into
the lungs. Hence, the person with asthma often finds it more difficult to expire (expel
the air) than to inspire. Furthermore, such labored breathing, after many years, often
results in the asthma-sufferer having a barrel-shaped chest.
1-12. STATUS ASTHMATICUS
Status asthmaticus is a very sudden, continuous, and intense asthmatic attack.
Emphysema is a condition in which the patient has large portions of the alveolar
walls destroyed. Consequently, the patient finds it necessary to breathe faster and
more deeply in order to obtain the oxygen needed to live. Emphysema is often
associated with smoking. Emphysema may also be referred to as Chronic Obstructive
Pulmonary Disease (COPD).
I-14. PULMONARY EDEMA
Pulmonary edema is a condition in which fluid collects in the interstitial spaces of
the lungs and in the alveoli. Obviously, the exchange of gases in the alveoli becomes
impaired. Pulmonary edema is usually caused when the left side of the heart fails to
pump efficiently; when this happens blood backs up into the pulmonary circulation and
causes fluid in the lungs.
Section IV. RESPIRATORY SYSTEM DRUGS
Drugs affecting the respiratory system have been in use for years. In the first
part of this century, for example, various members of the morphine family (that is,
heroin) were used in the treatment of coughs. In the 1980s, people are using both
legend and over-the-counter cough preparations. At certain times of the year you will
see many prescriptions for cough medicines and expectorants. You have probably