Call Us Now
+91********35Enquiry Us
**********artha@gmail.com
Call Us Now
+91********35Enquiry Us
**********artha@gmail.com
| Category | Lung Disease |
The word asthma originates from an ancient Greek word meaning panting. Essentially, asthma is an inability to breathe properly. When any person inhales, the air travels through the following structures:
Asthma is a chronic condition in which these airways undergo changes when stimulated by allergens or other environmental triggers. Such changes appear to be two specific responses:
These actions in the airway cause patients to cough, wheeze, and experience shortness of breath (dyspnea), the classic symptoms of asthma.
In the hyperreactive response, smooth muscles in the airways constrict and narrow excessively in response to inhaled allergens or other irritants. It should be noted that the airways in everyone's lungs respond by constricting when exposed to allergens or irritants. There are major differences, however, in the hyperreactive response that occurs in people with asthma:
The hyperreactive stage is followed by the inflammatory response, which generally contributes to asthma in the following way:
Inflammation appears to be present in the lungs of all patients with asthma, even those with mild cases, and plays a key role in all forms of the disease.
Asthma occurs in about five million American children and each year about 200,000 are hospitalized. It is the most common chronic childhood illness. About half of all cases of asthma develop before the age of 10 and about 80% develop symptoms before age five.
The mechanisms that cause asthma are complex and vary among population groups and even individuals. For example, asthma in children is highly associated with allergies. However, only a minority of children with allergies has asthma, and not all cases of asthma can be explained by allergic response. Other factors, such as genetics or environmental conditions are likely to be involved in the development of asthma. Most likely several genes are involved that make a child susceptible to environmental triggers, not only allergens, but also possibly infections, dietary patterns, or air pollution. Physical factors, particularly having smaller lungs, affect the chances for later asthma.
From 1980 to 1994, asthma increased 160% in American children younger than 4 years and has also dramatically risen worldwide. Experts are puzzling over the cause of this phenomenon. Among the causes and factors that are suspects in the dramatic rise in asthma in children are the following:
Asthma and allergies often coexist, and the allergic response plays a strong role in childhood asthma. About 70% to 85% of children with asthma have allergies, with the risk being higher from seasonal allergies (e.g. hay fever) than perennial allergies (e.g., indoor allergies). (It should noted, however, that allergies are very common, and studies report that only 1% to 20% of children with allergic rhinitis actually develop asthma.)
An asthma attack can be induced or aggravated by direct irritants to the lungs. Studies indicate that the more indoor allergens a child is allergic to, the higher the risk for severe asthma. Important irritants or allergens include the following:
The Allergic Response. The allergic process, called atopy, and its connection to asthma are not completely understood. It involves various airborne allergens or other triggers that set off a cascade of events in the immune system leading to inflammation and hyperreactivity in the airways. One description is as follows:
Over the course of years the repetition of the inflammatory events involved in asthma can cause irreversible structural and functional changes in the airways, a process called remodeling. The remodeled airways are persistently narrow and can cause chronic asthma. Researchers are trying to determine how this process occurs:
Interleukins. Some researchers are looking at potent immune factors, including interleukins 11 and 13. They have been linked to a number of processes possibly involved in remodeling, including, overgrowth of cells in the smooth muscles that line the airways and scarring in the airways.
Growth Factors. Compounds known as vascular endothelial growth factor (VEGF) have been observed in the airways of asthma patients. VEGF is a powerful promoter of cell growth in blood vessel linings and some researchers believe they may be major factor in remodeling.
About one-third of all persons with asthma share this condition with another member of their immediate family. Asthma may be more likely to be passed to children from the mother than from the father. Both allergies and asthma are strongly associated with hereditary factors and they share certain genetic markers, but they are not always inherited together.
Research, then, on the genetics of these conditions is confusing and difficult. Of some significant promise, researchers have identified a gene (ADAM33), which has been linked to asthma. The gene regulates one of the enzymes called metalloproteases, which are involved with the smooth muscle in the airway. A mutation of this gene, then, could play a role in airway changes that occur after inflammation.
The role of early childhood respiratory and intestinal infections is very complex. Viral respiratory infections certainly worsen existing asthma but the most common ones are unlikely to be causes of childhood asthma. In fact, early respiratory and intestinal infections may offer some protection against asthma.
Early Respiratory Infections as Causes of Asthma. Studies have found little evidence to suggest that most respiratory infections are important causes of asthma in children, except in certain cases. An important exception is the respiratory syncytial virus (RSV), which has been implicated in the development of asthma. RSV is the major viral cause of infant pneumonia. (Other respiratory infections may play an important role in many instances of adult-onset asthma.)
Common Respiratory Infections Worsen Asthma. It should be noted that even if the most common respiratory viruses, especially those that cause colds and flus, do not cause asthma in children, they can worsen asthma in children who have it.Rhinovirus, or the common cold virus, for example, has been reported to be the most common infectious agent associated with asthma attacks. In one study, it was associated with 61% of asthma exacerbations in children. Some research suggests that colds promote inflammation in patients with existing asthma and increase the intensity of airway responsiveness for weeks.
The Hygiene Theory: Early Infections as Protection Against Asthma. An increasingly important theory blames the dramatic increase in asthma on the reductions in childhood infections that have occurred with modern hygiene and antibiotic use. The basic theory rests on the idea that infections stimulate production of specific immune factors called TH1 cells. As these cells build up, they replace other immune factors called TH2 cells, which react to allergens--a less serious threat to the body. Without infections to stimulate the production of the TH1 infection fighters, then the TH2 allergen fighters are not replaced and they persist at high levels, making the growing child more susceptible to allergies and asthma.
A number of different studies support this theory:
The standard vaccinations against serious childhood infections, according to important studies in 2002 and 2003, pose no risk for asthma. One of the studies even reported some lower risk for asthma and allergies in the second and third years after vaccinations. Infections killed thousands of children every year before immunization became widespread. Asthma, although serious, is rarely fatal in children. No one should stop giving their children vaccinations against childhood killers.
GERD. At least half of asthmatic patients also have gastroesophageal reflux disease (GERD), the cause of heartburn. It is not entirely clear which condition causes the other or whether they are both due to common factors.
Some theories for the causal connection between GERD and asthma are as follows:
GERD is sometimes hard to detect and might be suspected as a contributor in the following asthmatic patients:
Treating GERD symptoms with anti-acid agents resolves asthma in some (but not all) patients who share both conditions. [ See Well-Connected, Report #85, Heartburn and Gastroesophageal Reflux Disease.]
Sinusitis. Almost half of children and adults with allergic asthma have sinus abnormalities, and in various studies, between 17% and 30% of asthmatic patients develop true sinusitis. The presence of sinusitis, however, does not appear to increase the severity of asthma.
Parental Migraines and Childhood Asthma. Some studies have reported a link between childhood asthma and parental migraines, with one small 2000 study suggesting that children are about five times more likely to develop asthma if their parents have a history of migraines.
Exercise-induced asthma (EIA) is a limited form of asthma in which exercise triggers coughing, wheezing, or shortness of breath. [ See Box Exercise-Induced Asthma (EIA).]
About 10% of asthmatic adults and some fewer children have aspirin-induced asthma (AIA). With this condition, asthma gets worse when patients take aspirin. Aspirin is one of the drugs known as nonsteroidal anti-inflammatory drugs (NSAIDs). Although aspirin is used to reduce inflammation in other disorders, it appears to have the opposite effect in many asthma cases. It is not wholly known why this occurs. AIA often develops after a viral infection. It is a particularly severe asthmatic condition and is associated with up to 25% of asthma-related hospitalizations. In about 5% of cases, aspirin is responsible for a syndrome that involves multiple attacks of asthma, sinusitis, and nasal congestion. Such patients also often have polyps (small benign growths) in the nasal passages.
Patients with aspirin-induced asthma (AIA) should avoid aspirin and most likely NSAIDs, including ibuprofen (Advil) and naproxen (Aleve).
Acetaminophen (e.g., Tylenol) has been the traditional alternative for relief of minor pain for patients who are aspirin-sensitive. Unfortunately, recent evidence has muddied these recommendations. In fact, some asthmatic episodes have been linked to high consumption of acetaminophen among adults. And a study of children with asthma reported that those who took ibuprofen were less likely to be hospitalized for asthma than those taking acetaminophen. This is of particular concern, since acetaminophen is the pain reliever of choice in small children.
Asthma occurs primarily at night (called nocturnal asthma) in as many as 75% of asthma patients. Attacks often occur between 2 and 4 A.M. Factors that might play role in nocturnal asthma may include one or more of the following:
Some experts believe that nocturnal asthma may actually be a unique form of asthma with its own specific biologic mechanisms that occur only at night and which reduce natural steroid hormones (which block inflammation).
Exercise-Induced Asthma (EIA)Exercise-induced asthma (EIA) is a limited form of asthma in which exercise triggers coughing, wheezing, or shortness of breath. This condition generally occurs in children and young adults, most often during intense exercise in cold dry air. Symptoms are generally most intense about 10 minutes after exercising and then gradually resolve. EIA is triggered only by exercise and is distinct from ordinary allergic asthma in that it does not produce a long duration of airway activity, as allergic asthma does. (It should be noted that some people have both forms of asthma.) People who only have EIA do not appear to require long-term maintenance therapy. A study of military recruits with EIA also reported that the condition does not hinder a person's overall physical performance. Medications Cromolyn, a mild anti-inflammatory agent, or short-acting beta2 agonists have been the treatments of choice for preventing EIA. Newer approaches for people who work out regularly include pretreatment with long-acting beta2 agonists, such as salmeterol (Serevent) or the regular use of inhaled corticosteroids. Hints for Reducing EIA EIA occurs only after exercise and is more likely to occur with regular paced activities in cold, dry air. The following are some suggestions for reducing its impact:
|
Asthma is the third major cause of hospitalization in children under age 15. The condition can be very serious in children, particularly those younger than five, because their airways are very narrow.
The severity of asthma is graded using the following categories: mild intermittent and mild, moderate, and severe persistent. [ See Table Classification of Asthma Severity and Preferred Maintenance Treatments under What Are the General Guidelines for Treating Asthma?] A patient in any of these categories, even mild intermittent, can still experience a severe and even life-threatening attack. In fact, according to one report, 30% of asthma deaths occur in patients with mild asthma.
Asthma is rarely fatal in children, with only 176 asthma deaths reported in 1999 in children under age 15. (About 444 fatalities occurred in people between ages 15 and 34.) But even these low numbers are unacceptable, since asthma deaths are largely preventable.
Factors associated with an increased risk of death from asthma in children include the following:
African-American children have more than six times the death rate of Caucasian-Americans in the age groups of four and under and 15 to 24 years. Hispanic children also have a higher risk. A 2002 study suggested that these children tend to be given inferior treatments compared to Caucasian children.
The following signs and symptoms may indicate a life-threatening situation:
Asthma often progresses very slowly to a serious condition or may develop to a fatal or near-fatal attack within a few minutes. It is very difficult to predict when an attack will become very serious. It should be noted that early symptoms or lack thereof do not always reflect the ultimate severity of an attack. In fact, some studies suggest that people at high risk for fatal or near-fatal asthma attacks are those with poor awareness of their own reduced ability to breathe and who are therefore slow in seeking help. Monitoring peak flow rates is, therefore, an important management component, since it provides a more accurate assessment of lung function than symptoms alone.
In a 2003 study, researchers followed people with asthma for longer than 30 years. About a third of children had outgrown their asthma in adulthood. In general, the more severe the childhood asthma, the greater the likelihood that it would persist. For example, only 23% of children who experienced wheezy bronchitis (wheezing during respiratory infections) suffered from frequent or persistent asthma in adulthood.
There is now some evidence that severe asthma can cause long-lasting damage and possibly permanent scarring in some patients. The risk for such injury is highest, however, when asthma strikes children in the first three to five years. Lung damage can also occur rapidly in asthmatic adults. There does not appear to be any significant risk for long-term lung damage for children who develop mild to moderate persistent asthma at age five to 12.Children adapt well to living with asthma, however, and even with severe asthma they can function as well as healthy children in virtually all areas of life.
Studies are mixed over the effects of emotional disorders on the severity of asthma. In fact, one indicated that parents of asthmatic children may suffer greater psychological stress than their children. A 2000 study, in fact, reported that having mild to moderate asthma does not significantly affect the psychological well being of most children aged 5 to 12. Teenagers and preteens have particular difficulty coping with what they perceive as the social stigma of asthma. Often they will deny their condition and refuse to comply with their drug regimen. Parents and older children should not hesitate to seek help from support groups, physicians, friends, or family members. Supporting programs in camp and school may help children to better manage their asthma and may even reduce hospitalization.
Although there have been few studies on the effects of asthma on schooling, a 2000 study reported that nocturnal (nighttime) asthma affected school attendance and performance in children and work attendance in their parents.
At this time, asthma affects about 5.3 million American children between the ages of 5 and 14, and some experts believe that about half of American children may be undiagnosed. Asthma has dramatically increased worldwide over the last few decades, in both developed and developing countries. From 1980 to 1994, asthma increased 160% in children younger than four years old and has risen dramatically in other countries as well. There is a wide variation in asthma incidence, however, ranging from over 50% among children in the Caroline Islands to virtually 0% in Papua New Guinea. The reasons for this wide variation are not yet known.
Among younger children, asthma develops twice as frequently in boys as in girls, but after puberty it may be more common in girls.
Urban Life. Urban life is strongly associated with a higher risk. Although poverty plays a significant role, urban life, in fact, has been associated with a higher risk for asthma in any income group and among both children and adults. In some urban areas, as many as 25% of children have asthma or show signs of wheezing. In fact, it may be greatly underdiagnosed in city children. A 1999 Chicago study reported almost a third of children in inner-city kindergartens had asthma symptoms without a diagnosis of the disorder; 10% had actually been diagnosed with asthma, mainly because their symptoms were severe.
Ethnicity. Since 1980, asthma rates have risen the most dramatically among African-American children, and they have significantly higher rates of asthma than Caucasian children. Hispanic children are also at higher risk. Both groups of minority children are more likely to have fatal asthma than Caucasian children.
Some studies indicate that the difference in risk exists simply because African-Americans and other minority groups are more likely to live in urban areas. Poverty and lack of access to health care may also play a role. However, Caucasian children who live in cities also face a high risk for asthma, and rural African-American children do not.
Urban life and socioeconomic factors, however, may not fully explain the ethnic disparity. For example, a 2000 study found that African-American children may have significantly higher levels of IgE than Caucasian children, suggesting a genetic susceptibility. (IgE are immune factors that play a critical role in asthma.)
Low Birth Weight. Infants of low birth weight are at higher risk for lung problems and asthma.
Winter Birth. One study suggests that children born in the winter are at greater risk for asthmatic allergies to cockroaches than children born at other times of the year.
Breast Feeding. Most studies on breastfeeding report some protection against wheezing and asthma in the first year of life. It should be noted that breastfeeding has many other benefits for the child as well.
Complications of Pregnancy. According to a 2000 study, complications of pregnancy, specifically those involving the mother's uterus (such as post-birth hemorrhage, pre-term contractions, insufficient placenta, and restricted growth of the uterus), are associated with an increased risk of childhood asthma. Another 2000 study also reported that delivery procedures such as Cesarean section, the use of vacuum extraction or forceps also raised the risk of childhood asthma.
In both adults and children, the incidence of obesity and asthma has been increasing in parallel over recent years. Studies report a strong association between the two conditions. Some experts suggest that excess weight pressing on the lungs may trigger the hyperreactive response in the airways typical of asthma. Others believe that asthma leads to obesity by inhibiting physical activity, although studies in 2000 and 2001 found no difference in activity levels between people with or without asthma. One 2000 study suggested that many obese people may be misdiagnosed as having asthma when in fact they are simply short of breath, possibly because of the increased effort required for breathing.
In any case, there is some evidence that losing weight can relieve asthma symptoms. Weight loss in anyone who is obese and has asthma or shortness of breath reduces airway obstruction and improves lung function. [ See Well-Connected Report #53 Weight Control and Diet.]
Damp Homes. Studies from different parts of the world reported that children who live in damp homes have a much higher risk for asthma.
Parental Migraines and Childhood Asthma. Some studies have reported a link between childhood asthma and parental migraines, with one small 2000 study suggesting that children are about five times more likely to develop asthma if their parents have a history of migraines.
Mental Health. Research indicates that poor mental health of parents and children are significant predictors of more severe symptoms in childhood asthma. A 2000 study, in fact, suggested that high stress levels can predict the onset and severity of asthma in children genetically at risk for asthma.
In children with asthmatic symptoms, it is particularly important to first consider as a possible cause inhaled foreign objects such as peanuts, viral infections such as croup, and bacterial infections, which may be accompanied by high fever and progress rapidly. Any child who has frequent coughing or respiratory infections should be checked for asthma.
The classic symptoms of an asthma attack are the following:
The end of an attack is often marked by a cough that produces a thick, stringy mucus. After an initial acute attack, inflammation persists for days to weeks, often without symptoms. (The inflammation itself must still be treated, however, because it usually causes relapse.)
The doctor will seriously consider a diagnosis of asthma if the child has a history of periodic attacks of shortness of breath, coughing, and wheezing, perhaps accompanied by tightness in the chest. The parent should describe the pattern of symptoms and possible precipitating factors, including the following:
A number of disorders may cause some or all of the symptoms of asthma: Panic disorder can coincide with asthma or be confused with it. Other diseases that must be considered during diagnosis are pneumonia, bronchitis, severe allergic reactions, psychosomatic illnesses, and certain rare disorders (such as tapeworm and trichomoniasis).
If symptoms and a patient's history are indicative of asthma, the physician will usually perform tests known as pulmonary function tests to confirm the diagnosis and determine the severity of the disease.
Using a spirometer, an instrument that measures the air taken into and exhaled from the lungs, the physician will determine several values:
1. Vital capacity (VC), which is the maximum volume of air that can be inhaled or exhaled.
2. Peak expiratory flow rate (PEFR), commonly called the peak flow rate, which is the maximum flow rate that can be generated during a forced exhalation.
3. Forced expiratory volume (FEV1), which is the maximum volume of air expired in one second.
If the airways are obstructed, then these measurements will fall. Depending on the results, the physician will take the following steps:
Another method for inducing airway resistance is to administer cold air. This test is very accurate for ruling out asthma, but it is not sensitive enough to accurately identify adults who actually are asthmatic.
The patient may be given skin or blood allergy tests, particularly if a specific allergen or occupational agent is suspected and available for testing. Allergy skin tests may be the best predictive test for allergic asthma, although they are not recommended for people with year-round asthma.
Tests that either rule out other diseases or obtain more information about the causes of asthma include the following:
Investigative measurements of certain chemicals in sputum or exhaled air that indicate airway inflammation. Such chemical markers include nitric oxide and hydrogen peroxide. For example, high levels of nitric oxide in exhaled air is proving to be a simple and noninvasive way of diagnosing asthma.
Treating an Acute Attack in the Hospital. An acute attack may require hospitalization. Laboratory tests, an electrocardiogram (ECG), and a chest x-ray are performed to determine lung function, oxygen levels, and other indications of severity or rule out other causes. Depending on the results, the following treatments may be given:
Of note, antibiotics are not useful for asthma attacks if there is no strong evidence of the presence of a bacterial infection. (Viral infections, most often colds and flus, are more likely to trigger an asthma attack. In such cases, antibiotics do not appear to be beneficial and may have adverse effects.)
Discharge and Relapse After Hospitalization. It typically takes about three to four hours to determine if a patient can be safely sent home or if they need to stay. Patients are generally discharged under the following circumstances:
Despite reasonable precautions, between 12% and 16% of patients relapse within two weeks. Receiving a steroid injection at discharge or taking an oral corticosteroid five to seven days after leaving the hospital can reduce this risk significantly.
Avoiding allergens, following appropriate drug treatments, and home monitoring are key elements in preventing dangerous asthma attacks and hospitalization. In addition, good communication between the physician and patients is a key factor in a successful management program. [ For information on lifestyle changes for managing asthma, see What Are Lifestyle Ways to Manage Asthma And Reduce the Allergic Response?]
A combination of medications is important and effective for both treating and preventing asthma attacks. Parents can greatly reduce the frequency and severity of their children's asthma attacks by understanding the difference between coping with asthma attacks and controlling the disease over time. According to a few studies, most parents do not discriminate between medications that provide rapid short-term relief and long-term symptom control. Medications for asthma are categorized by their ability to (1) relieve symptoms and (2) control inflammation and reduce the chances for long-term injury.
Asthma flare-ups are much more common in children who do not comply with the prescribed treatment. In spite of the importance of this two-pronged approach, a significant number of moderate or severely asthmatic patients overuse their inhaled beta-agonists and underuse their corticosteroid medications. Studies report that less than half of children with severe asthma take a daily anti-inflammatory, and only a third use a peak flow meter to monitor their disease. The situation is far worse in inner city children with asthma, a group at high risk for severe complication.
Classification of Asthma Severity and Preferred Maintenance Treatments |
|||
|
Classification |
Symptoms |
Lung Function |
Preferred Maintenance Treatment |
|
Mild intermittent |
General Symptoms: Occur twice a week or less. No symptoms and normal lung function between attacks. Attacks are brief (from a few hours to a few days) and may vary in intensity. Nighttime Symptoms: Occur twice a month or less. |
FEV 1 or PEF is 80% or more than predicted. PEF variability is less than 20%. |
Children five years and under: No daily medication.
Children over five and Adults: No daily medication. If severe attacks occur, oral, injected, or intravenous corticosteroids recommended. |
|
Mild Persistent |
General Symptoms: Occur more than twice a week, but less than once a day. Asthma attacks may be severe enough to affect activity. Nighttime Symptoms: More than twice a month. |
FEV 1 or PEF is 80% or more than predicted, PEF variability is between 20% and 30%. |
Children five years and under: Low-dose inhaled corticosteroids (with nebulizer, or MDI with holding chamber with or without face mask) Alternative: cromolyn or leukotriene-antagonist
Children over five and Adults: Low-dose corticosteroids. Alternative: cromolyn, leukotriene antagonist, nedocromil, or sustained release theophylline. |
|
Moderate Persistent |
General Symptoms: Symptoms occur daily that require use of inhaled short-acting beta2-agonists. Symptoms twice a week or more and may last for days. Asthma attacks twice a week or more and may be severe enough to affect activity. Nighttime Symptoms: More than once a week. |
FEV 1 or PEF is between 60% and 80% of predicted, PEF variability is more than 30%. |
All Age Groups: Low to medium-dose inhaled corticosteroids and long-acting beta2-agonists.
Alternative: Corticosteroids plus leukotriene antagonist or theophylline |
|
Severe Persistent |
General Symptoms: Continual symptoms. Limited physical activity. Frequent asthma attacks. Nighttime Symptoms: Frequent. |
FEV 1 or PEF is 60% or less than predicted, PEF variability is more than 30%. |
All Age Groups: High-dose inhaled corticosteroids and long-acting beta1-agonists plus (if needed) oral corticosteroids.
|
|
NOTE: An individual should be assigned to the most severe grade in which any feature occurs. The characteristics described are general and may overlap because asthma is highly variable. Many life-threatening situations have started in patients categorized with mild intermittent asthma. An individual's classification may also change over time. |
|||
|
Adapted from National Asthma Education and Prevention Program (National Heart, Lung, and Blood Institute) Second Expert Panel on the Management of Asthma. Expert panel reports 2: guidelines for the diagnosis and management of asthma. Bethesda, Md.: National Institutes of Health, 1997; publication no. 97-4051. Updated 2003: NAEPP Expert Panel Report. Guidelines for the Diagnosis and Management of Asthma. Update on Selected Topics 2002 |
|||
Most asthma drugs are inhaled using various forms of inhalers or nebulizers. Inhaled agents must be used regularly as prescribed and the patient carefully trained in their use in order for them to be effective and safe. Studies suggest that many children fail to use the devices properly, although newer devices are easier to use than others. The basic devices are the metered-dose inhaler (MDI), breath-actuated inhalers, dry powder inhalers, and nebulizers.
MDIs have used chlorofluorocarbons (CFCs) as their propellants, which are damaging to the environment. Over time CFS is being replaced with other propellants (e.g., hydrofluoroalkane) that are equally effective to CFCs, are environmentally safe, and do not chill the device as CFCs do. Devices that don't use propellants at all are also now available. [ see below].
Metered-Dose Inhaler. The standard device for administering any asthma medication has been the metered-dose inhaler (MDI). This device, particularly when used with a holding chamber, allows precise doses to be delivered directly to the lungs. MDI-delivered drugs must be used regularly as prescribed and the patient carefully trained in their use in order for them to be effective and safe. Some patients hold the MDI too close to their mouths, or even inside them. Others may exhale too forcefully before inhalation. The holding chamber, or spacer, allows the patient additional time to inhale the medication and so improves delivery. They vary, however, in their ability to deliver medication. For example, in one study the AiroChamber-Plus was more effective than the EasiVent in delivering an inhaled steroid. It should be noted that often MDIs continue to deliver propellant after the drug has been used up. Patients should track their medicine and throw the device away when the last dose has been administered. Nebulizers (not MDIs) are typically used in very small children, both at home and in the emergency room. However, recent studies suggest that with the use of a face mask and a spacer, the MDI is effective even for infants in the emergency room and may prove to be useable at home.
Breath-Actuated Inhalers. Breath-actuated rotary inhalers (e.g., Easi-Breathe and Autohaler) deliver the drug directly to the back of the throat as the user inhales. Their primary advantage over the MDI is their ease of use. They also do not use CFCs as propellants. In comparison studies, patients have been very successful with the breath-actuated inhalers. They are not recommended for children under eight years old.
Dry Powder Inhalers. Dry powder inhalers (DPIs) deliver a powdered form of beta2 agonists or corticosteroids directly into the lungs. They also do not use CFCs. Such devices include Rotahaler, Spinhaler, Turbohaler, Clickhaler, Easyhaler, Diskhaler, Discus, Twisthaler, Spiros, and others. DPIs are as effective as the older devices, and generally have a better taste and are easier to manage. They may differ among themselves, however, in their ability to deliver drugs into the airways. In one study, for example, the Turbohaler was easier to use than the Diskhaler and so achieved better delivery. The Discus is another effective DPI; it has a dose counter and protects against exhalation effects. More research is needed.
Humidity or extreme temperatures can affect their performance, so they should not be stored in humid places (e.g., bathroom cabinets) or locations subject to high temperatures (e.g., glove compartments during summer months).
Dry-powder may cause tooth erosion and children are advised to rinse their mouths out right after taking the drug and to brush twice a day with a fluoride toothpaste.
Other Hand-Held Inhalers. Respimat delivers a fine-mist spray that is created by forcing the liquid medication through nozzles. It does not use any propellant.
Nebulizers. A nebulizer is a machine that delivers a fine spray of medication-containing liquid. Nebulizers are often used for children younger than three years and sometimes for older children who have difficulty using the MDI. It takes five to 10 minutes to administer any medication using a nebulizer. And, because the spray is less targeted than with the inhaler, it must deliver large amounts of the drug. This increases the risk for toxicity and severe side effects. Nebulizers should not be used by children who can manage an inhaler. Their use has been associated with a higher rate of hospitalizations and longer duration of symptoms than inhalers. If children must use an albuterol nebulizer, parents should be sure that it does not contain the preservative benzalkonium, which actually narrows the airways.
Asthma triggers a vicious emotional-physical cycle:
Caregivers must first focus on alleviating their own anxiety, which can heighten a child's own fears. The next step is to help the child relax. One method for this is as follows:
This exercise both relaxes the child and discourages shallow, oxygen-poor breathing. Massaging the child in gentle circles on the chest is relaxing and may also loosen mucus.
Other recommendations include the following:
Many adults self-manage their asthma using daily monitoring of peak air flow with adjustments of the medications as needed. It involves the use of a peak flow meter, which measures peak expiratory flow rate (PEFR). Studies suggest, however, that for most children with asthma, an educational program is just as effective for managing the condition as monitoring. Most children, then, do not need to monitor their peak air flow on any regular basis.
Beta2-agonists do not reduce inflammation or airway responsiveness but serve as bronchodilators, relaxing and opening constricted airways during an acute asthma attack. A short-acting inhaled beta2-agonist, taken as needed, is often the only medication used by children with chronic mild asthma.
Specific short-acting beta2-agonists include the following:
Short-acting bronchodilators are generally administered through inhalation and are effective for three to six hours. They relieve the symptoms of acute attacks, but they do not control the underlying inflammation. If asthma continues to worsen with the use of these
Side Effects of Beta2-Agonists. Side effects of all beta2-agonists include the following:
Loss of Effectiveness and Overdose. There has been some concern that both short-acting beta2-agonists become less effective when taken regularly over time, increasing the risk for overuse. Over time some patients may become tolerant to many effects of short-acting beta2-agonists. The degree to which this affects the airways is uncertain. In some studies, the duration of action has declined but the peak effect appears to be preserved, making these drugs still useful for acute attacks. Regular use of long-acting beta2-agonists may increase the chances of a reduced effect from the short-acting forms.
Theophylline. Theophylline (Theo-Dur, Theolair, Slo-Phyllin, Slo-bid, Constant-T, Respbid) is a mild to moderate bronchodilator that has been used to treat childhood asthma for more than 30 years. It is useful for treating nocturnal asthma and may also have anti-inflammatory qualities even in low doses.
Available in tablet, liquid, and injectable forms, some theophylline sustained-release tablets and capsules have a long duration of action and can therefore be taken once or twice a day with good results.
It does have some problems, however. Side effects include changes in behavior, mood, and memory. If theophylline is not taken exactly as prescribed, an overdose can easily occur. Toxicity causes the following symptoms: nausea, vomiting, headache, insomnia, and, in rare cases, disturbances in heart rhythm and convulsions. A physician should be contacted immediately if any of these side effects occur.
The risks for these adverse effects are small if the drug is taken exactly as prescribed but the following precautions should be noted:
If a child is taking theophylline on an ongoing basis, the doctor should monitor the drug level at the start of therapy and at regular intervals thereafter.
Anticholinergic Agents. Inhaled ipratropium bromide (Atrovent) acts as a bronchodilator over time. Ipratropium bromide alone is only modestly beneficial for acute asthma attacks. In fact, the drug is not approved specifically for asthma. Some parents report benefit for treating wheezing in infants. It is also sometimes used in the emergency room to treat children with severe asthma to enhance the effects of intravenous beta2-agonists.
Corticosteroids, also called glucocorticoids or steroids, are powerful anti-inflammatory drugs. Steroids are not bronchodilators (that is, they do not relax the airways) and have little effect on symptoms. Instead, they work over time to reduce inflammation and prevent permanent injury in the lungs. Many studies have now shown that the use of inhaled corticosteroids in patients with moderate to severe asthma significantly reduce the rate of rehospitalizations and deaths from asthma. Nevertheless, they are still significantly underprescribed in the patients who need them most.
Inhaled Corticosteroids. Inhalation of corticosteroids makes it possible to provide effective local anti-inflammatory activity in the lungs with minimal systemic effects. (Oral steroids have considerable side effects.) They are currently recommended as the primary therapy under the following circumstances:
Examples of inhaled corticosteroids are the following (not all are available to children):
