Asthma

(Bronchial asthma, reversible hyperreactive lung disease)

Asthma is a chronic disease in which the air passages, or bronchi, overact to normally harmless substances or circumstances. When these triggering factors enter the bronchi, the airways constrict to hinder the flow of air in and out of the lungs. Very soon, the bronchi become inflamed, and the membranes lining them secrete a sticky mucus. The result is wheezing, coughing, and difficulty in breathing. A severe attack can be life-threatening.

Asthma triggers vary from person to person; some of the most common are allergens such as pollen, animal dander, and house dust; irritants such as air pollution, tobacco smoke, perfumes, and chemicals; cold air; certain foods and food additives; aspirin and related medications; anxiety and stress; and vigorous exercise.

No one knows why some people develop hyperreactive lungs, although an inherited predisposition appears to play a role. Many people think that emotional problems are a major cause, but researchers have discounted this. Asthma is a difficult disease that may lead to emotional problems, and stress can sometimes provoke a flare-up, but it is not itself a psychological disorder. Although asthma differs from an allergic reaction, allergies are often involved and can also trigger attacks.

Most common in children, asthma often subsides during adolescence, but never fully disappears. It is not unusual for adults to suffer a recurrence after going years without a flare-up. This return often as not comes on the heels of a respiratory infection.

Diagnostic Tests and Procedures

Wheezing and other symptoms may point to asthma, but lung function tests will still be necessary to distinguish it from other disorders. Testing begins with spirometry to measure the amount of air that is breathed in and out of lungs under different circumstances. Spirometry is sometimes combined with challenge testing to identify the specific asthma triggers and to measure the effectiveness of medications. In a challenge test, the patient is exposed to a suspected trigger and its effect is then measured by spirometry.

Medical Treatments

Doctors approach asthma treatment with two major goals: to prevent attacks and to reverse any flare-up as quickly as possible. Prevention entails teaching patients how to control their disorder with drugs, lifestyle changes, and, increasingly, alternative therapies.

Asthma patients are also taught to use a peak-flow meter, a simple handheld device that measures the amount of air that can be exhaled after taking a deep breath. A drop in the normal peak-flow reading points to an imminent attack; an increase indicates that therapy is working. Prompt treatment with bronchodilator drugs to open the airways during an asthma attack can usually stop it before it becomes an emergency.

The most common prescription medications for asthma are: Beta-2 Agonists. These drugs, most of which both prevent and stop attacks, are the most widely used asthma medications in the United Stales. Included are albuterol (Preventil and ventolin), isoetharine (Bronkometer), metapro-terenol (Alupent and Meiaprel), and terbutaline (Brethine). Available in pill, liquid, and aerosol forms, they work by relaxing the muscles that control the airways. They also reduce the flow of mucus by inhibiting histamine production, and help to clear mucus from the lungs. Their side effects include shakiness, tremor, and an increased heart rate; long-term use can cause anxiety and restlessness.

Another drug in this class, epinephrine (Adrenalin), is inhaled or injected, and works faster and more forcefully than other beta-2 agonists. It is usually reserved for severe attacks that are not controlled by the other medications.

Xanthines. This category includes aminophylline (Mudrane) oxtriphylline (Choledyl), theophylline (Slo-Bid, Theo-Dur, and others), and dyphylline (Dilor and Lufyllin). These drugs, which are chemically related to caffeine, relax and open the airways, allowing more air to flow. They also make the heart beat faster and stimulate breathing. Difficulty in finding the right dosage is their major drawback, because the margin between a safe, effective blood level and a dangerously high one is very narrow. Theophyllines work best when they are taken daily, thereby maintaining a constant level of the drug in the bloodstream.

Adverse reactions to a small overdose include agitation, headache, nausea, abdominal cramps, and palpitations. A larger overdose can cause serious irregular heartbeats and convulsions. Once a safe dosage is found, however, the drugs are highly effective.

Adrenocorticoids. These drugs are related to steroid hormones produced by the adrenal glands. Aerosol steroids include beclomethasone (Vanceril and Beclovent), flunisolide (AeroBid), and triamcinolone (Azmacort); the most common oral and injected form is prednisone. Steroids are potent antiinflammatory medications that are highly effective in treating severe asthma. Experts recommend that they be used in high doses for a short period of time to stop a sustained flare-up. Their long-term use is limited by their side effects, which include lowered immunity, bone loss, weight gain, and mood swings and other mental changes.
Because they can cause growth problems and other long-term adverse side effects, their use in children is limited to severe asthma that cannot be controlled by other medications.

Cromolyn Sodium. This inhaled antihistamine, marketed as Intal, is highly effective in preventing asthma, but it does not help during an actual attack. It is especially beneficial in preventing asthma that is triggered by allergens, exercise, and environmental chemicals or pollutants, it may be taken just before exercising or, if appropriate, used several times a day. Because some people briefly experience coughing or breathlessness immediately after inhaling cromolyn sodium, it can worsen an asthma attack. Otherwise, it is a safe drug with minimal side effects.

Alternative Therapies

Despite favorable anecdotal accounts, it has not been proven that acupuncture, chiropractic, reflexology, and other manipulative techniques are of much help against asthma. Also, the Bach flower remedies and other forms of aromatherapy may actually trigger an attack in asthmatics who are sensitive to perfumes. In contrast, alternative approaches that emphasize breathing exercises and relaxation, or that help to increase physical endurance are important adjuncts to medical treatment, especially if they reduce the need for steroids and other powerful drugs.

Alexander Technique. By using this training to improve posture and learn proper breathing methods, asthma patients are often able to increase their control over the disease.

Biofeedback, Hypnosis, and Visualization. These techniques help asthmatics gain a measure of control over breathing and other normally involuntary functions. When practiced during the early, or prodrome, stages of an attack, they may even abort it.

Homeopathy. Practitioners recommend a number of substances, including aconite, arsenicum album, and phosphorus. If a flare-up does not improve within a few minutes, however, a conventional drug should be used.

Hydrotherapy. Swimming is one of the best exercises for asthma because it improves endurance and increases lung capacity in an environment free of dust and other asthma triggers. Taking a hot shower or relaxing in a warm tub of water are also beneficial; the warmth eases tensions and the moist air helps clear the lungs of mucus.

Massage. This provides an excellent means of countering stress. Massage combined with postural drainage -- a percussive tapping of the back while the head is lower than chest -- clears mucus from the lungs.

Meditation and Yoga. These and other relaxation therapies are useful in overcoming the stress that often precipitates an asthma flare-up. They can also lessen the stress and panicky feeling that can exacerbate an attack.

Nutrition Therapy. Many foods and food additives, especially sulfites, will trigger asthma in susceptible people. A nutrition therapist can help identify such foods, and structure a balanced diet that eliminates them. One should avoid, however, an overly restricted diet that does not provide adequate nutrition. Some high-dose supplements, especially beta carotene, vitamins C and E, and magnesium, are touted as being beneficial for asthma sufferers, but they should not be taken without the guidance of a doctor or nutritionist.

Self-Treatment

Careful self-treatment is the key to keeping asthma under control. First and foremost, identify what sets off an attack and then make every effort to avoid it. If a triggering factor cannot be avoided, take a preventive drug such as cromolyn sodium. Other important self-care measures include:

• Take asthma medications correctly. To allow inhaled drugs to penetrate to the smallest airways, thereby increasing their effectiveness, use a nebulizer, or extender, instead of a metered-dose inhaler, or whiffer. Check with your doctor if you are uncertain as to how or when to take medication.
• Practice daily postural drainage to help loosen and remove mucus from your breathing passages.
• Contact your doctor immediately if I you catch a cold or other respiratory infection. Increasing preventive medication at this time can help ward off j a severe flare-up.
• Do not smoke, and don't allow anyone to smoke in your home, office, car, or other surroundings.
• Keep a diary of symptoms that signal an impending attack (for example, unproductive coughing, apprehension, rapid breathing). When you sense one coming on, do breathing exercises, perhaps combined with meditation or visualization, to overcome it. Also drink a glass of water; this keeps mucus thin and flowing, rather than § thick and sticky. If necessary, take a preventive dose of medication.
• Avoid inhaling cold air. If you have to go out when its cold, cover your face and inhale through your nose.
• Stay indoors when air pollution or pollen counts are high. If you must go outdoors, wear a protective face mask.

Other Causes of Difficult Breathing

Panic attacks may produce wheezing 3 and a choking sensation similar to those of asthma. In children, chronic i adenoid and sinus infections can be mistaken for asthma, as can cystic fibrosis. Among adults, congestive heart failure and a number of chronic lung disorders, such as emphysema, chronic bronchitis, and bronchiectasis should also be ruled out.