Pediatric Annals

Office Evaluation and Management of Pediatric Asthma

Jacob Hen, JR, MD

Abstract

Asthma is one of the most common chronic disorders encountered by the pediatrician, affecting m mas many as 11% of school-aged children in the United States. Pediatrie hyperreactive airway disease is the major cause of school absenteeism and often results in emotional stress for the patient and femily, financial burden for family and third party payers, and is still an occasional cause of death when patient, family, and/or physician fail to recognize the child at risk.1·2 Diagnosis relies on history, physical examination, X'ray studies, and pulmonary function testing. Optimal management requires a therapeutic and education plan involving both patient and parents as well as a thorough understanding by both physician and patient/family of the pathogenesis, pathophysiology, and clinical features of asthma. With current management, most asthmatic children can be expected to lead a healthy and active lifestyle with normal intellectual and emotional development.

EVALUATION OF THE ASTHMATIC PATIENT

History

A complete history is of utmost importance when evaluating a patient for asthma. Information to be obtained is summarized in Table 1. More complete details are available in a review by Leffert.3 While a characteristic history of recurrent wheezing is often obtained, occasionally the history is less obvious. Recurrent or nocturnal cough (cough variant asthma), exercise- related symptoms (exercise-induced bronchospasm), hyperinflation, right middle lobe syndrome, or recurrent infiltrates on chest x-ray may be the only signs or symptoms of asthma. One must keep in mind that coughing, wheezing, tachypnea, shortness of breath , and the chest x-ray findings listed above may be signs or symptoms of other diseases such as cystic fibrosi?, infections, congenital anomalies of the respiratory or cardiovascular system, foreign body aspiration, H type tracheoesophageal fistula, aspiration and/or gastroesophageal reflux.4

Physical Examination

A complete physical examination is also necessary and findings should be correlated with the history. In the stable or mild asthmatic patient, findings are often normal. Patients with chronic, severe asthma are often thin, short, and may have chest deformities (pectus carinatum, Harrison sulcus, increased AP diameter of the chest, elevated shoulders) suggesting long-standing hyperinflation of the lungs and poorly controlled small airway obstruction. The presence of a barrel chest has been associated with a poor prognosis.5 Clubbing of the nails is rare in asthma and should alert the pediatrician to extensively search for other problems.6 Wheezing on expiration and rales are common findings during periods of poor control. Occasionally, one encounters an abnormal chest exam in a patient who denies current symptoms, which can be explained by chronic adaptation to airway obstruction. Physical examination should include auscultation of the chest before and after coughing and exertion. If there is a productive cough usually found in children over 10 years of age) attempts should be made to examine sputum. A clear mucoid or pale yellow sputum is compatible with asthma, while a dark yellow or green sputum may indicate suppurative lung disease which requires appropriate cultures and further evaluation. Microscopic examination of sputum is not helpful unless infection or certain other diseases are suspected.

Chest X-Ravs

A recent chest x-ray (PA and lateral) and any previous x-rays should be reviewed on all asthmatic patients during their evaluation. Hyperinflation of the lungs (hyper luce ncy, flattening of the diaphragm, increase in AP diameter on the lateral view) is commonly present during acute asthma, however between acute symptoms the chest x-ray is often normal in mild asthmatic patients. Areas of atelectasis (often misinterpreted as pneumonia), increased linear markings and peribronchial thickening may also be seen. Occasionally in severe asthma, lobar atelectasis, pulmonary edema, or extrapulmonary air (pneumomediastinum, pneumothorax) are seen. The chest x-ray is most helprul to exclude other…

Asthma is one of the most common chronic disorders encountered by the pediatrician, affecting m mas many as 11% of school-aged children in the United States. Pediatrie hyperreactive airway disease is the major cause of school absenteeism and often results in emotional stress for the patient and femily, financial burden for family and third party payers, and is still an occasional cause of death when patient, family, and/or physician fail to recognize the child at risk.1·2 Diagnosis relies on history, physical examination, X'ray studies, and pulmonary function testing. Optimal management requires a therapeutic and education plan involving both patient and parents as well as a thorough understanding by both physician and patient/family of the pathogenesis, pathophysiology, and clinical features of asthma. With current management, most asthmatic children can be expected to lead a healthy and active lifestyle with normal intellectual and emotional development.

EVALUATION OF THE ASTHMATIC PATIENT

History

A complete history is of utmost importance when evaluating a patient for asthma. Information to be obtained is summarized in Table 1. More complete details are available in a review by Leffert.3 While a characteristic history of recurrent wheezing is often obtained, occasionally the history is less obvious. Recurrent or nocturnal cough (cough variant asthma), exercise- related symptoms (exercise-induced bronchospasm), hyperinflation, right middle lobe syndrome, or recurrent infiltrates on chest x-ray may be the only signs or symptoms of asthma. One must keep in mind that coughing, wheezing, tachypnea, shortness of breath , and the chest x-ray findings listed above may be signs or symptoms of other diseases such as cystic fibrosi?, infections, congenital anomalies of the respiratory or cardiovascular system, foreign body aspiration, H type tracheoesophageal fistula, aspiration and/or gastroesophageal reflux.4

Physical Examination

A complete physical examination is also necessary and findings should be correlated with the history. In the stable or mild asthmatic patient, findings are often normal. Patients with chronic, severe asthma are often thin, short, and may have chest deformities (pectus carinatum, Harrison sulcus, increased AP diameter of the chest, elevated shoulders) suggesting long-standing hyperinflation of the lungs and poorly controlled small airway obstruction. The presence of a barrel chest has been associated with a poor prognosis.5 Clubbing of the nails is rare in asthma and should alert the pediatrician to extensively search for other problems.6 Wheezing on expiration and rales are common findings during periods of poor control. Occasionally, one encounters an abnormal chest exam in a patient who denies current symptoms, which can be explained by chronic adaptation to airway obstruction. Physical examination should include auscultation of the chest before and after coughing and exertion. If there is a productive cough usually found in children over 10 years of age) attempts should be made to examine sputum. A clear mucoid or pale yellow sputum is compatible with asthma, while a dark yellow or green sputum may indicate suppurative lung disease which requires appropriate cultures and further evaluation. Microscopic examination of sputum is not helpful unless infection or certain other diseases are suspected.

Chest X-Ravs

A recent chest x-ray (PA and lateral) and any previous x-rays should be reviewed on all asthmatic patients during their evaluation. Hyperinflation of the lungs (hyper luce ncy, flattening of the diaphragm, increase in AP diameter on the lateral view) is commonly present during acute asthma, however between acute symptoms the chest x-ray is often normal in mild asthmatic patients. Areas of atelectasis (often misinterpreted as pneumonia), increased linear markings and peribronchial thickening may also be seen. Occasionally in severe asthma, lobar atelectasis, pulmonary edema, or extrapulmonary air (pneumomediastinum, pneumothorax) are seen. The chest x-ray is most helprul to exclude other serious diseases such as parenchymal lung disease, cardiac disease, congenital anomalies of the cardiovascular and respiratory systems, and foreign bodies. Once the initial chest x-rays are reviewed, there is little need to repeat them in the future unless focal findings on physical examination are suggestive of lobar atelectasis or consolidation, extrapulmonary air, or the patient has severe symptoms and signs suggestive of respiratory failure.

Table

TABLE IASTHMA HISTORY

TABLE I

ASTHMA HISTORY

Pulmonary Function Testing

Pulmonary Function Tests (PFTs) are helpful as a diagnostic tool to confirm the presence of asthma. In addition, during long-term management, PFTs can provide objective data on the degree of airway obstruction present, to determine response to therapy, and permit therapeutic changes to be made. One may encounter a patient without current symptoms and abnormal PFTs, so-called "silent asthma."7 In daily office or clinic practice, the measurement of Peak Expiratory Flow Rate (PEFR) with a Mini Wright Peak Flow Meter is recommended at every visit. Although PEFR is effort dependent and measures only large airway flow, good results can be obtained from cooperative children as young as 5 years of age. Pulsus paradoxus, a measure of airway obstruction, should be measured at every visit.8 With practice it is easy to measure on patients at any age and requires only a sphygmomanometer and stethoscope. Hospital PFT laboratories familiar with testing children can perform more sophisticated testing on most children by 6 years of age. Flow volume curves and spirometry (pre- and post-exercise and bronchodilator challenge) are useful during initial evaluation and subsequent follow-up.9 While PFTs are compared to "standards" for height and sex, it is most useful to compare results to the patient's previous and "best" results. An important goal for every patient is to achieve as normal a PFT as possible.

Other Tests

Unless the history, physical examination, chest xrays, and PFTs suggest a problem other than hyperreactive airways, there is little to be gained by further testing. 10 The role of allergy testing is presently not clearly defined since the place for hyposensitization in childhood asthma is fairly limited.1,10

MANAGEMENT

Since no two asthmatic patients are the same and asthma changes as the child grows, at the onset of therapy it is important to individualize a therapeutic plan and goals, discuss them with the family, and review them on a regular basis. Education, self-management skills, environmental control, drug therapy, and exercise are the cornerstones of pediatrie asthma management today.

Education/Self'Management

By today's standards, treatment of childhood asthma is suboptimal and may even fail unless the patient (when old enough), family, and school personnel are educated about asthma, including self-management skills. The costs of asthma care, morbidity, and even mortality can be significantly reduced, compliance improved, and all other aspects of asthma care made easier for the pediatrician, parent, and patient when early asthma education takes place.

Environmental Control

Simple measures of environmental control can be helpful for most asthmatic patients. If specific precipitating factors can be identified by history, they should be avoided if possible. Unless history reveals that symptoms occur after eating a particular food, there is little benefit from a restricted diet. The role of cow's milk in asthma is unclear at present. There is no evidence that removing cow's milk products from the diet will affect the course or prognosis of asthma in most children; those with true cow's milk allergy will have a clear-cut response to its ingestion. Measures to reduce house dust, control humidity (air conditioner in summer, humidifier in winter), and reduce airborne irritants are helpful but should not enslave the family. Electrostatic air purifiers have little beneficial effect.

Exposure to woodburning stoves, fireplaces, kerosene heaters, hobbies that produce noxious fumes, and ingestion of aspirin, aspirin-containing compounds, tartrazine food colors, and metabisulfites (food preservatives) should be avoided. Passive exposure to tobacco smoke and older teenagers' smoking should be discouraged. When choosing a job, the patient should consider exposure to airway irritants and working environment. Allergy to pets is a relatively unimportant cause of asthma in children. Occasionally, children do develop symptoms after contact with a pet and then avoidance is necessary. Removal of a long-owned pet is usually unnecessary unless there is a definite relationship between exposure and symptoms. It makes sense to recommend that families not purchase new pets or replace present ones, and keep pets out of the patient's bedroom (and preferably out of the house) to cut down on house dust.

Immunotherapy

The role of immunotherapy in the treatment of childhood asthma remains controversial. Hyposensitization may help those patients who are sensitive to one or two specific allergens (especially with concomitant allergic rhinitis) where avoidance of these allergens is not possible, however childhood asthma is rarely characterized by this pattern. Further studies are needed to determine if immunotherapy has a place in the long-term management of childhood asthma and whether it can favorably influence prognosis and outcome.1,10

Physiotherapy /Exercise

Relaxation and breathing exercises may help children during periods of symptoms (eg, during sports) breathe more easily and reduce anxiety. Poor posture should be corrected. Regular exercise in the form of gym class, swimming and interval phase sports is recommended for all asthmatic patients to improve physical fitness, instill confidence, and promote socialization. Exercise-induced bronchospasm can be controlled to even allow participation in varsity level sports. Parents and school teachers should be encouraged to allow a normal lifestyle with as few restrictions as possible; excuses from gym class should be avoided.

Psychotherapy

With the proper initial education of patient, parents, and school teachers at an early age, many potential psycho-emotional problems can be avoided. Often the pediatrician can play a major role here by allaying anxiety within the family. Many of the emotional problems seen are the result of asthma rather than the cause of it. Occasionally counseling, family therapy, psychotherapy, or behavior modification therapy are indicated. Rarely a "parentectomy" (sending the child to a long-term care, education, se If- management facility away from the family environment) is indicated.

Diary Card

With difficult to control asthma or inadequate history, it may be helpful for patient/family to maintain a home diary card to record symptoms, medications, activity, and PEFR (Figure 1). Assessment of drug compliance is quite important; from 50% to 80% of children and/or parents do not use asthma drugs as they were prescribed. ' Use of such a diary card requires a reliable recorder of data.

Figure 1. Asthma Home Diary.

Figure 1. Asthma Home Diary.

Drug Therapy

The major groups of drugs currently used in asthma management are xanthenes, sympathomimetics, cromolyn sodium, and corticosteroids. The use of bronchodilators in infants, especially those less than I year of age is controversial due to the belief that infants are unresponsive to such therapy. The currently available data are crude and limited because of the inability to easily perform objective PFTs at this age. Despite this, some infants with wheezing do respond to xanthenes and/or sympathomimetics and it is generally recommended that infants with asthmatic symptoms and signs be given an adequate trial of bronchodilator therapy when supportive measures fail.10

1. Sympathomimetic agents - With the recent development of newer and safer drugs, beta 2 adrenergic agents have replaced theophylline and the older sympathomimetic agents as the drugs of choice for acute and chronic asthma therapy. The newer drugs (albuterol, bitolterol, metaproterenol, terbutaline) have a longer duration of action, increased dosing interval, and fewer side effects (alpha and beta 1 effects) when compared to the older, less selective drugs (adrenaline, ephedrine sulfate, isoproterenol). No one drug currently available is superior in all respects. These drugs result in bronchodilitation by stimulating airway smooth muscle beta 2 receptors which increases Cyclic AMP (CAMP) and alters calcium flux across the cell membrane. Other actions include stimulation of mast cell membrane beta receptors (inhibition of mediator release) and increased mucociliary transport. Improvement in symptoms and PFT is dose -dependent, occurs shortly after administration, and is maximal at 2 hours for the newer drugs. The maximum, safe dose is dependent on side effects: tremor with the newer agents; tachycardia, palpitations, hypertension with the older agents. With prolonged use, tolerance may occur. Initial concerns over increased deaths in patients using beta 2 agonists have not been substantiated.11

Table

TABLE 2RECOMMENDED PEDIATRIC DOSAGE SCHEDULE FOR SELECTED BETAADRENERGIC BRONCHODILATORS CURRENTLYAVAILABLE IN THE UNITED STATES

TABLE 2

RECOMMENDED PEDIATRIC DOSAGE SCHEDULE FOR SELECTED BETAADRENERGIC BRONCHODILATORS CURRENTLYAVAILABLE IN THE UNITED STATES

Administration: The beta adrenergic agents may be administered by the inhaled, oral, or patenterai route. Products, dosages, and routes of administration for the agents currently available in the United States are summarized in Table 2. The inhaled route is the preferred method of administration since the drug is delivered directly to the target organ, the onset of action is more rapid, the dose is smaller, and the side effects are less frequently seen when compared to the oral route. For older children, teenagers, and adults, the metered dose inhaler (MDl) is recommended for ease of use and convenience, especially for those patients who manage their own asthma and participate in sports. Young children may benefit from spacer devices used with beta 2 agonist MDI.12 For infants and uncooperative children, adolescents, and adults, the use of a home compressed air driven nebulizer with a face mask has gained recent popularity (Figure 2). Normal saline or cromolyn sodium can be used to dilute the beta 2 agonist to a final volume of 2 ml (which takes approximately 20 minutes to nebulize). This method of delivery does not require much patient coordination or cooperation and can be used in crying and dyspneic patients as well. In the stable patient, there is no difference in response to drug administration by MDI or nebulizer. For patients at any age with acute, severe symptoms nebulization is the preferred route. Whatever delivery system is chosen, proper education and supervision in their use is required.

2, Cromolyn sodium is a prophylactic drug rather than a bronchodilator; it prevents the lung from reacting to whatever stimulus triggers the asthma (irritant, allergen, exercise, cold air, etc.).13 This drug inhibits calcium flux across mast cell membranes and prevents mediator release. In addition, it may block irritant receptors in the lung. Cromolyn sodium is not active orally or parenterally, thus it must be administered by inhalation. Children as young as 6 years can be taught to use the powder form in a spinhaler while the 2% solution can be given to younger children and infants by use of a home nebulizer. It is the safest asthma drug on the market with good patient/family acceptance and almost no side effects. Occasionally the powder may cause coughing. When this occurs one should consider trying the nebulizer form.

Figure 2. Use of a home compressed air driven nebulizer with face mask has gained popularity and is well-accepted by infants and children. Photograph supplied by DeVilbis, Somerset. Pennsylvania.

Figure 2. Use of a home compressed air driven nebulizer with face mask has gained popularity and is well-accepted by infants and children. Photograph supplied by DeVilbis, Somerset. Pennsylvania.

Administration: For optimal protection, cromolyn sodium must be used daily. To begin treatment, 20 mg (one capsule of powder, one vial of liquid) is inhaled 4 times a day for a trial period of no less than 12 weeks. With clinical improvement, the dose can often be reduced to 2 or 3 times a day. It is advisable to inhale a beta 2 agonist via MDI prior to using the spinhaler or to mix the cromolyn with a beta 2 agonist when using a nebulizer for maximal lung penetration.

Patients with perennial asthma should use cromolyn sodium continuously while patients with seasonal asthma may do well with use only during periods of trouble. Beneficial effects, seen in 60% to 80% of all patients, include: reduction in symptoms, acute attacks and hospitalization, need for concomitant steroid or theophylline therapy, improvement in PFTs, and an improvement in exercise ability and lifestyle. The duration of treatment is dependent on the individual. Because of the high rate of spontaneous improvement in childhood asthma, if the patient is improved when cromolyn sodium is used, treatment should be stopped after 1 year to see if symptoms recur. The long-term use of cromolyn sodium appears to be safe. Cromolyn sodium need not be stopped during acute exacerbations of asthma and can be given by nebulizer in place of spinhaler until symptoms resolve.

Table

TABLE 3FACTORS WHICH ALTER THEOPHYLUNE CLEARANCE

TABLE 3

FACTORS WHICH ALTER THEOPHYLUNE CLEARANCE

3. Theophylline has been used for many years to treat asthma. Newer information on its pharmacokinetics and mechanisms of action as well as newer product formulations have increased its safety and efficacy. Oral theophylline is indicated when asthma is not controlled by beta 2 agonists and cromolyn sodium. The dosage form used should be one of the sustained release preparations rather than the unpalatable liquid or "combination" preparations. Theophylline was once thought to be a bronchodilator by inhibiting phosphodiesterase and increasing airway smooth muscle CAMP. It now appears that its actions are the rseult of multiorgan adenosine receptor stimulation. Theophylline is a central respiratory stimulant, it improves respiratory muscle contractility and prevents respiratory muscle fatigue, has a positive inotropic cardiac effect, produces pulmonary and systernie vasodilatation, as a diuretic may reduce lung water and improve lung compliance, and may prevent the release of mast cell mediators. 10

A therapeutic serum theophylline level is defined to be 10 to 20 fig/ml. With levels above 7 µg/ml pulmonary function usually improves. At levels above 20 µg/ml most patients experience side effects. Up to 30% of patients often with subtherapeutic levels are unable to take theophylline because of undesirable side effects (vomiting, hyperactivity, insomnia) that may not be dose-related.10 In addition to individual variation of theophylline clearance, there are many factors that alter clearance (Table 3). Theophylline clearance is markedly reduced in infants less than 1 year of age and adults. Suggested dosing regimens should be used as guidelines and dose and dosing interval adjusted by measuring serum levels at reliable laboratories. Maximum age-specific dosage requirements to maintain a peak serum level at 14 µg/ml are listed in Table 4, however in general when starting theophylline it is wise to use two-thirds of this total daily dose.

After four or five drug half-lives, steady state serum theophylline concentrations can be attained. Both peak and trough levels should then be measured to determine proper dose and dosing intervals. With the newer sustained release preparations, most infants and children can be dosed 3 times per day while teenagers and adults can be dosed twice a day. The new "once a day" preparations have not proven useful in pediatrics. Recent data suggest that the absorption of each of the sustained release preparations may vary; one should be familiar with the preparation being used and its pharmacokinetics. H After initial individualization of dosing requirements and intervals, peak serum levels should be measured in we 11- control led patients to assure that toxic levels are not present, while for poorly controlled patients trough levels are important to ensure that the dose, dosing interval and theophylline formulation are optimal. Because of potential side effects, beta 2 agonists are preferred over theophylline in asthmatic infants less than 1 year of age.

4. Corticosteroide - Steroids are valuable in the treatment of severe, chronic asthma. They inhibit inflammatory responses induced by chemical, mechanical, or immunologie stimuli, inhibit the release of prostaglandins and vasoactive substances, potentiate stimulation of CAMP synthesis, and increase mucociliary clearance.15 Steroids can be administered by the inhaled, oral, or parenteral route. Few patients require daily steroids and even the most severe cases can often be adequately managed by low dose, alternate day, morning prednisone which reduces many of the side effects. When needed for acute symptoms, short "bursts" of less than 2 weeks of daily prednisone are usually uncomplicated by adverse side effects in patients who are not on chronic steroids. Patients on corticosteroide for more than 1 year should have ophthalmologic screening for cataracts (reversible with discontinuation of steroids) and receive calcium supplementation in their diet to prevent bone demineralization. The use of inhaled steroids has enabled many patients to come off oral steroids, however major drawbacks include side effects with large, frequent doses and limited pediatrie usage to patients old enough to use MDIs with or without spacers (the only form available).12 Alternate day, low dose, morning prednisone is still recommended for the severe chronic infant or young child unable to use an MDI. Cortícosteroids are reserved for the patient who is poorly controlled with beta 2 agonists, cromolyn sodium, and theophylline and should never be used as the only medication in asthma.

5. Anticholinergic agents - The importance of vagai influences in asthma has recently been emphasized and has renewed interest in anticholinergic agents to control asthma. Currently, the only available agent in the United States is nebulized atropine (0.05 to 0.1 mg/kg/dose) which is recommended only for inpatient asthma treatment. Recent studies have failed to show any side effects of such therapy. 16 We will see newer anticholinergic agents used for asthma treatment in the future. There may be an important place for these drugs in the treatment of the steroiddependent patient and those with exercise -induced bronchospasm.10

6. Antihistamines, once thought to be contraindicated in asthma because of their drying effect on respiratory secretions, can safely be used but have no prophylactic or therapeutic effect on asthma. When used alone or in combination with decongestants, they may improve hay fever and allergic rhinitis and thus reduce mouth breathing (especially during exercise) and may indirectly help asthma. With the recent introduction of nasal and ophthalmoiogic cromolyn sodium, the usefulness of antihistamines for hay fever and rhinitis may be limited.

Table

TABLE 4MAXIMUM MEAN AGE-SPECIFIC DOSAGE REQUIREMENTS TO MAINTAIN A PEAK SERUM THEOPHYLUNE LEVEL OF 14 µß/ML WHEN STARTING THERAPY USE 2/3 OF THIS DOSE

TABLE 4

MAXIMUM MEAN AGE-SPECIFIC DOSAGE REQUIREMENTS TO MAINTAIN A PEAK SERUM THEOPHYLUNE LEVEL OF 14 µß/ML WHEN STARTING THERAPY USE 2/3 OF THIS DOSE

Table

TABLE 5DRUG THERAPY IN VARIOUS PATTERNS OF ASTHMA

TABLE 5

DRUG THERAPY IN VARIOUS PATTERNS OF ASTHMA

7. Antibiotics are rarely necessary in the management of asthma. They are most commonly prescribed during acute symptoms for "bronchitis" and when infiltrates are seen on chest x-ray. In reality, the bronchitic cough seen in asthma is most often due to increased mucous production (part of asthma) and the infiltrates represent atelectasis, not pneumonia. In the majority of asthmatic children, infection does trigger acute asthma, however it is usually viral in nature. One point to remember when prescribing erythromycin is that it decreases theophylline clearance.

8. Expectorants and mucolytìc agents - These agents have never been proven helpful in asthma. Potassium iodide may suppress thyroid function when taken chronically. The only proven way to loosen pulmonary secretions is to provide humidification of ambient air and ensure adequate systemic hydration by taking oral fluids.

9. Cough suppressants - The only effective cough suppressants are narcotic sedatives. When an asthmatic patient coughs, it often signals poor asthma control, post-nasal drip, or an upper respiratory tract infection. All cough suppressants are con tra indicated in asthma because of their respiratory center depression which may mask early signs of hypoxemia (irritability, lethargy) and depress respiratory drive. In addition, barbiturates may alter theophylline clearance.

PATTERNS OF MANAGEMENT

In general, treatment must be individualized to the patient. One should try to achieve the maximum control of symptoms and normalization of PFTs with the safest and least number of medications. By gathering data from the history, physical examination, and PFTs, one can separate patients into treatment groups according to disease severity (Table 5).1,10

Mild Episodic Asthma: 70% to 75% of asthmatic children make up this group. Acute symptoms occur every few months, often precipitated by viral respiratory infections, and the child is symptom-free (with normal or near normal PFTs) for extended periods of time between episodes. Also included in this group are patients with cough variant asthma and exerciseinduced bronchospasm. When beta 2 agonist therapy alone fails to control symptoms, most patients can be well-controlled by the addition of chronic, prophylactic inhaled cromolyn sodium.

Frequent Episodic Asthma: 20% to 25% of asthmatic children comprise this group. These patients have acute symptoms every 4 to 6 weeks (if not properly managed) and often have lesser, more frequent symptoms as well. PFTs may remain abnormal until proper control is achieved. Most of these patients will require chronic, prophylactic inhaled cromolyn sodium and daily beta 2 agonist therapy. Intermittent theophylline is indicated for acute symptoms. Occasionally a short course of steroid therapy is required for the more difficult to control patients. If there is a seasonal pattern to the asthma, there may be times when less intensive therapy may be adequate to control symptoms.

Chronic Severe Asthma: 1% to 5% of asthmatic children are in the group which is characterized by the presence of daily symptoms, limitation of physical activity and exercise, severely abnormal PFTs at initial evaluation, and evidence of chronic hyperinflation on physical examination. Initially these patients require aggressive, intensive management to control their disease which includes inhaled beta 2 agonists, cromolyn sodium and theophylline. If this therapy proves inadequate, corticosteroids (oral for severe and young patients, inhaled for older patients) should be started. Acute symptoms should be controlled by more frequent use of inhaled beta 2 agonists and/or a short course (5 to 7 days) of high dose, daily prednisone (1 to 2 mg/kg) given in the morning. Very few of these patients require chronic, daily prednisone, but if they do, every effort should be made to put the patient on alternate day corticosteroide and if the patient is old enough to use inhaled steroids when the asthma is under control. The use of cromolyn sodium often has a steroid sparing effect. Once symptoms are controlled and PFTs normalized, it may be possible to reduce the numbers of medications one at a time to the point where the patient is well-controlled on beta 2 agonists and cromolyn sodium. If there is a seasonal pattern to the asthma, there may be times when less intensive therapy may be adequate.

REFERENCES

1. Landau U: Outpatient evaluation and management of asthma. RrduirrCimNoithAm 1979; 26:581-601.

2. Strunk RC, Mrazek DA, Fuhrmann GSW. et al: Physiologie and psychological characteristics associated with deaths due to asthma in childhood A case controlled study. JAMA 1985; 254:1193-1198.

3. Leffcn F: The management of chronic asthma. J JWwrr 198Oi 97:875-885.

4. Williams HE, Phelan PD: RejfmaiorjIDnesi m Children. Melbourne, Bloctwell. 1975. pp 106-115.

5. Martin AJ1 Landau LI, Phelan PD: The effect on growth of childhood asthma. AcM ftdutr Stand 198 1; 70:683-688.

6. Warig WW: Tfa history arriphysicaf examination, in Kendig EL, Chemicl V(eds): Disorders of Ar Resprraun-j Trocí m Children, ed 4. Philadelphia, WB Saunders Co. , 1983, pp 67-68.

7. Cooper DM. Cuti E, Lev ison H: Occult pulmonary abnormalities in asymptomatic asthmatic children. Chest 1977; 71:361-364.

8. Galant SP, GroncyCE, Shaw KC: The value of pulsus paradoxus in assessing the child with status asthmaticus. ftdtnncj 1978; 61:46-51.

9. Tauuig LM, Lernen R]: Interpretation of pulmonary function tests in children, m Sackner MA (ed): Lung Biology in Health and Distase: Diagnostic Techniques in Pulmonary Discole. New York, Marcel Dekker. Inc.. 1981.

10. Isles A. Levison H: Treatment of childhood asthma. I RespDû (suppl). August 198!; 60-71.

11. Ebsition Statement: Adverse effects and complications of treatment with beta-adrenenjic agonist drugs. Committee on Drugs. American Academy of Allergy and Immunology. } ABerflr CIm Jmmunul 1985; 75:443-449.

12. König P: Spacer devices used with metered dose inhalers: Breakthrough or gimmick. Chest 1985; 88:276-284.

13. Bernstein IL: Cromolyn sodium. Chest (suppl) 1985; 87:68-73.

14. Hendeles L, Xfeinberget M: Theophylline product and dosing interval seleciion for chronic asthma. ) AUn0 CIm inominal 1985; 76:285-291.

15. Siegel SC: Overview of corticosteroitj therapy. J Allergy Ciin immuto! I9SS; 76:112-320.

16. Cavanaugh MG, Cooper DM: Inhaled atropine sulfate: Dose response charac teilst ics. Am Rev Resptr Du 1976; 1 14:517-524.

TABLE I

ASTHMA HISTORY

TABLE 2

RECOMMENDED PEDIATRIC DOSAGE SCHEDULE FOR SELECTED BETAADRENERGIC BRONCHODILATORS CURRENTLYAVAILABLE IN THE UNITED STATES

TABLE 3

FACTORS WHICH ALTER THEOPHYLUNE CLEARANCE

TABLE 4

MAXIMUM MEAN AGE-SPECIFIC DOSAGE REQUIREMENTS TO MAINTAIN A PEAK SERUM THEOPHYLUNE LEVEL OF 14 µß/ML WHEN STARTING THERAPY USE 2/3 OF THIS DOSE

TABLE 5

DRUG THERAPY IN VARIOUS PATTERNS OF ASTHMA

10.3928/0090-4481-19860201-09

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