Asthma
by Erica Lindquist

Willie James was an important and well liked blues player with strong roots in Maxwell Street, going so far as to call his band the Maxwell Street Blues Band. He died on October 24, 1997 from an asthma attack.

Asthma attacks will awake even the soundest sleepers. Some of my earliest memories are or creeping at two and three in the morning into my sister’s room during one of her attacks. My mother would sit all night by her bed, making sure she was still breathing.

Asthma affects people from all walks of life; singers and athletes, businessmen and sales clerks, overall affecting about four to eight percent of the population of the United States. This common disorder is the reason behind one and a half and two million emergency room visits each year in the United State. Asthma attacks account for two to ten percent of hospital visits in urban centers.

The death rate of asthma has climbed forty percent, from thirteen deaths per million in 1982 to nineteen deaths per million in 1991. Increased cases of the disorder have been seen in Australia, Canada, the United Kingdom, Switzerland and Germany. African-Americans and Puerto Rican Hispanics have an eleven percent and six percent, respectively, prevalence of asthma, compared to the three percent of Caucasians. Before the age of ten, twice as many boy have asthma than girls. Between eighteen and fifty-four years of age, this statistic is reversed in favor of the male population.

The trachea, or windpipe, terminates at what are referred to as the bronchi. The first branches of the bronchial tree are the left and right primary bronchus. Upon entering the lungs, these split into secondary, or lobular, bronchi. The secondary bronchi continue on and split into the tertiary, or segmental, bronchi, which become the smaller bronchioles. The smallest branches are at the termination of the bronchioles, the terminal bronchioles. As the diameter of the airway decrease, so does the amount of cartilage. The quantity of smooth muscle, however, increases.

During an attack, airways are blocked by swelling of the bronchial membranes, spasms of smooth muscle cells, and mucus secretions, making it hard to breathe. Mild attacks include a tight feeling in the chest, wheezing and spitting up mucus. In a severe attack, the sufferer may become breathless or have trouble speaking. The neck muscles become tight, lips and fingernails take on a bluish cast, and the skin and muscles around the ribs may become concaved. Physician should watch for hypoxemia, cyanosis, acidosis, pneumonthorax, and abnormal breathing sounds. Many times, the attack will appear to ease, only to return, often more severe than the first. This is referred to as the ‘second wave’.

An important factor in acute asthma attacks are antibody-antigen interactions. There interactions stimulates membrane phospholipase to produce arachidonic acid. Arachidonic acid is metabolized by cyclo-oxygenase to form vasoactive prostaglandins, such as thromboxanes and prostacylins, or leukotrienes and their precursors. These are potent smooth muscle contractors that cause or contribute to existing airway constriction and inflammation. Aspirin is cyclo-oxygenase inhibitor which causes severe spasms of the smooth muscles. This sensitivity is reversed by leukotrienes, providing evidence that leukotrienes are important mediators of asthma.

Asthma attacks can be triggered by a wide variety of things. The more obvious are infections of the airways and allergens, such as cat dander. Exercise and weather, specifically dry and cold or drastic changes, may prompt an attack of wheezing. Air pollution, organic particles, such as cotton (byssinosis), red cedar, and detergent manufacture (B. subtilis), are common triggers. One of the more surprising is yellow dyes, especially tartrazines, found in gelatin. Perimenstral women are four times more likely to be hospitalized for an attack, due to the decrease of estrogens and the downregulation progesterone receptors. A common chemical irritant is toluene diisocyanate. Triggers of nocturnal asthma are low serum epinephrine levels, high serum histamine levels, acid reflux, sinusitis or post-nasal drip. Pregnant women carry special risk during an attack. Maternal hypoxia may harm the fetus.

It is more difficult to diagnose asthma in the elderly. Symptoms of asthma are also common to myocardial ischemia or pulmonary embolism.

To treat asthma, there are two main types of medications. Bronchodialators help to stop asthma attacks already in progress by relaxing the smooth muscles. Anti-inflammatories aim to prevent the attack. They reduce inflammation and the secretion of mucus. These drugs are sold under many brand names and forms. They may be given as powders, sprays, pills, liquids or shots Examples of anti-inflammatory medications are cromolyn, nedocromil, cromolyn sodium, long-acting beta-2 agonists, theophylline, and corticosteroids. Leukotriene modifiers are a relatively new medication, approved by the FDA in 1996. Some brochodialators are short-acting beta-2 agonists and ipratropium bromide.

Steroids are intended to decrease swelling in the bronchial tubes, reduce mucus production, decrease hyperactivity of the airways, help smooth muscle respond muscle relaxant medications, and stabilize pulmonary activity. Corticosteroids are anti-inflammatory hormones. They can be given topically as a cream or spray. Corticosteroids are also given internally as a liquid, tablet, or injection. Long term use of steroids, especially those taken orally, is not recommended. If overused, corticosteroids may result in ulcers, weight gain, cataracts, high blood pressure, decreased growth in children, high blood sugar, thinning of bones and skin. Prednisone is a commonly prescribed steroid for asthma and allergies. It is given as a pill or liquid. Short term side effects include a slight weight gain, an increased appetite, menstrual irregularities and cramps, heartburn and indigestion. Cortisone inhalers are recommended for those with daily moderate to severe attacks. About five percent of users suffer from hoarseness and thrush, these minor side effects can be reduces by simply rinsing the mouth out after inhaler use. When steroid usage is terminated, users often suffer minor withdrawal symptoms, such as loss of energy, poor apatite, and muscle or joint pains. In 1998, it was discovered that African American teenagers are three times as likely to be resistant to steroids used to treat asthma as Caucasians.

Two other preventative asthma medications are cromolyn sodium and nedocromil. They are inhaled directly into the lungs to inhibit later, as well as immediate, symptoms. The medicines work to stop the effects of environmental irritants and allergens. Cromolyn sodium comes in the form of a powder, used with a spinhaler, a liquid for a nubulizer machine, an inhaled form. There are few side effects of this drug. Nedocromil also comes in an inhaler form. Antihistamines and ketotifen are still undergoing clinical testing, waiting to be approved in the United States.

Recent testing has determined the effectiveness of leukotriene inhibitors has been promising. The purpose of Montelukast and other such drugs it to block the secretions of leukotriene from inflamed cells in the membranes of the airways. Montelukast is given in the form of a chewable tablet, currently most effective in children ages six to fourteen years.

Bronchodialators' purpose is to open the airways by relaxing the smooth muscles of the airways. To date, there are two types of bronchodialators; beta-adrenergic agonists, or beta-2 agonists, and methylxanthines.

Beta-2 agonists are adrenalin-like medications. They can be taken orally as tablets of liquid, inhalation or injection Injections of beta-2 agonists are used primarily in asthmatic emergencies. Inhaled forms of these are the choice in acute flare-ups and for prevention of exercise-induced attacks. Inhaled beta-2 agonists are available in metered-dosed inhalers, dry-powder capsules, or compressor-driven nebulizers.

Theophylline is the major methylxanthine used in asthma therapy. It serves mainly as a  bronchodialator for mild to moderate asthma attacks. The sustained-release form of theophylline us useful for fending off nocturnal attacks, sometimes used in conjunction with beta-2 agonists to give additional relaxation to the smooth muscle. Methylxanthines may also help to reduce muscle fatigue and has some anti-inflammatory effects. Unfortunate side effects may include abdominal pain, nausea, vomiting, nervousness, and insomnia.

Immunotherapy is the name for a procedure which involves small amounts of allergens to create a tolerance or resistance to allergens. Specifically, those allergens which trigger asthma attacks.

Medications will not effect all patients the same way. Any one or more of the following may indicate that a change in asthma treatments is in order: inordinate adverse effects resulting from the present medication, waking up at night from asthmatic symptoms more than twice a month, increased use of short-acting beta-2 agonists (more than three or four times a day), long term overuse of inhaled short-acting beta-2 agonists, over- or misuse of long-acting beta-2 agonists, nonadherence to anti-inflammatory medications, failure to produce a timely and sustained response, poor tolerance to physical activity, missing school or work for asthmatic reasons, or emergency rom visits due to asthma.

In an emergency room situation, specialized drugs are often required. One such medication is glucocorticoid named methylprednisolone. It is used when the sufferer is not responding to beta-2 agonists. It restores the body’s response to the agonists. It usually takes about four to six hours to work. Other emergency asthmatic drugs include ipratropium, aminophylline, adrenergics by the names of epinephrine and terbutaline, magnesium, ketamine, or halothane in one to two percent strengths.

Inhaled medications are preferred over oral ones. The patient, however, must use the inhaler correctly for the medication to be properly administered. Spacers are recommended for children using inhalers. The inhaler should be held upright, cap removed, and shaken. One should hold the head back slightly and breath out. Medication is optimally released about one or two inches from the mouth and breathed in slowly over three to five seconds. Breathe should be held for about ten seconds to keep medication in the lungs. Over-the-counter asthma inhalers contain epinephrine, an extremely weak and short-acting bronchodialator. Dry powder inhalers work a bit differently. With one of these, it is important to close the mouth tightly over the opening and breathe in quickly.

Injecting asthma suffers with antibodies to fight their own immune cells may be their greatest hope in alleviating asthma symptoms. The inflamation in asthmatic attacks is mediated by the immune cells called the eosinophil. The eosinophil are, in turn, controlled by the CD4 T-lymphocyte. Keliximab is a genetically engineered monoclonal antibody that acts against the CD4 T-lymphocytes to treat asthmatics.

Asthma is a common, inconvenient, and sometimes deadly disease. It is, however, completely treatable. Because asthma is a genetic disorder, there no known cure as of now. The best hopes for a cure lie in the area of genetic therapy for those who suffer from it, and slight genetic manipulation to prevent the future generations from suffering this disorder.


__

[search] [notes] [papers] [articles] [zine] [links] [forum] [chat] [about] [disclaimer] [main]