Special Feature: Pediatric Asthma 2002: Concerns, Controversies, and Creative Options
Special Feature
Pediatric Asthma 2002: Concerns, Controversies, and Creative Options
By Michael W. Felz, MD
Asthma is childhood’s most common chronic disease, affecting 5 million patients younger than age 18. Admissions for reactive airway disease have increased sharply for children younger than age 4, especially among African-Americans, and asthma deaths have doubled in recent decades. Asthma is a major cause of school absenteeism. Despite novel new therapeutic agents for asthma, and extensive insights into pathologic and immunologic aspects of the disease, cases are mounting and emergency department (ED) visits by children represent up to 10% of total census.1 Why these troubling trends? Where is current research leading?
Concerns
Asthma is a challenging diagnosis to confirm, with features that may vary between symptomatic episodes.2 Characteristics include reversible inflammatory airway obstruction manifesting as dyspnea, wheeze, cough, abnormal pulmonary function tests (PFTs), and tendency to recurrence. Common triggers are viral infection, allergen exposure, atopy, passive smoking, and exercise. Physical evaluation may be difficult due to young age, limited air movement, inability to perform PFTs adequately, and inconsistent physician (and parental) perception of severity of airflow compromise.3 A recent survey of 571 Massachusetts pediatricians illustrates considerable disagreement (60% consensus) over combinations of factors for diagnosing asthma, and only 10% identified PFTs as necessary.4 Even with the availability of National Institutes of Health (NIH) practice guidelines updated in 1997, physicians and parents often are deficient in compliance, with large gaps in assessment tools and medication usage.5 Inertia of previous practice, and lack of recent training, have been prominent in failure of adherence to guidelines.6 Fewer than than two-thirds of surveyed pediatric ED physicians employ peak expiratory flow rate (PEFR) in evaluating children, and only 50% suggested home PEFR monitoring after discharge.7 The advent of leukotriene (LT) inhibitors has met with mixed acceptance, despite evidence that these agents are moderately effective as first-line therapy for "young, wheezy preschoolers."8
Controversies
While ß2-agonists and systemic steroids are of proven value in acute asthma attacks, the data on maintenance medications—such as inhaled corticosteroids (ICS), cromolyn, nedocromil, long-acting ß2-agonists (LABA), and LT modifiers—are sorely limited in small children. Only theophylline has a labeled indication for children younger than age 2, whereas cromolyn and one LT modifier, montelukast, are indicated at age 2, and ICS and salmeterol (LABA) at ages 4-6.9 Clinicians must weigh desired benefits on airway dynamics against a myriad of side effects from agents with diverse mechanisms of action, and medication choices are far from standardized.10 There even is controversy over whether use of a metered dose inhaler with spacer is as efficacious as nebulizer therapy in the pediatric ED, although equal benefit has been demonstrated previously.11,12 Even in regions of high ß2-agonist usage by physicians, ICS prescribing in children falls far short of national guidelines.13 Some experts boldly claim that allergists, not pediatricians, provide better care for asthmatic children and are more cost effective.14 In 1528 severely asthmatic children requiring intensive care unit (ICU) admission, usage of mechanical ventilation and invasive monitoring varied widely by institution and level of hypercarbia, emphasizing lack of uniformity even among academic centers.15 The bottom line is that, for both out- and in-patients with asthma, significant heterogeneity exists among primary care and specialist physicians making key therapeutic decisions.
Creative Options
What evidence-based interventions for asthma are wise in the pediatric ED? One group showed that oral dexamethasone (0.6 mg/kg/d × 2 doses) was superior to prednisone (2 mg/kg STAT, then 1 mg/kg/d × 4 more days), with better compliance, less vomiting, and reduced school absence.16 This provides a shorter, more tolerable, two-dose regimen for asthmatic children in the office or ED, and may keep them in school more. Mixing medication with pudding, chocolate syrup, or applesauce seemed to improve children’s cooperation. For children with troublesome side effects from nebulized ß2-agonists, it is noteworthy that, compared to racemic albuterol 2.5 mg, the R-isomer levalbuterol (Xopenex) 0.16-1.25 mg was shown equally effective in increasing forced expiratory volume in one second (FEV1) in 43 children ages 3-11, but tremor and tachycardia were less frequent.17 Levalbuterol may, therefore, prove attractive if side effects limit compliance to traditional nebulizer therapy. In 182 Dutch infants and children ages 0-3 years who required nebulizer therapy, the novel "Babyhaler" device demonstrated 93% ease-of-handling scores among both parents and practitioners.18 This mask-valve-chamber tool resembles spacer devices widely employed in American EDs for administration of bronchodilators or maintenance medications to very young children.
In what ways can physicians keep children out of the ED? In a persuasive study of 11,195 asthmatic children ages 3-15 years in three urban areas, those prescribed daily controller medication (ICS, cromolyn, or nedocromil) had a relative risk of needing an ED visit of 0.4 (95% confidence interval [CI]: 0.3-0.5) and of hospitalization of 0.4 (95% CI: 0.3-0.6) over a one-year follow-up period.19 This information should prove useful at time of discharge for "frequent flyers" in the ED or inpatient ward. Within the ED, addition of a nebulized anticholinergic, ipratropium (250 mcg), to a common regimen of nebulized albuterol (2.5 mg) and oral prednisone (2 mg/kg) in 427 asthmatic children resulted in a 28-minute (13%) reduction in treatment time and required fewer albuterol doses (3 vs 4) compared to placebo.20 This lends credence to the "triple therapy" approach, which is becoming more standard, and rightfully so, in some centers. The impact of magnesium therapy recently was analyzed from five adult and two pediatric randomized trials involving 668 patients, concluding that this promising therapy demonstrated non-significant benefits in most patients. Only in severe exacerbations were admissions reduced (OR = 0.10) and PEFR improved (52 L/min).21 This data must be evaluated in light of a recent trial in 30 children ages 6-18 years with asthma refractory to ß2-agonists and intravenous steroids. In this small cohort, intravenous magnesium 40 mg/kg resulted in significantly improved asthma scores vs. placebo. Of note, eight of 16 treated patients (50%) were discharged home, while all 14 placebo recipients required admission.22 Perhaps single dose magnesium could play a beneficial role as a rapid, safe, and effective adjunct to traditional asthma therapy in the ED.
Not to be overlooked is reduction in home tobacco exposure, which has been shown to lower recurrent ED visits (OR = 0.32) among minority children of smoking parents.23 Likewise, clinicians must be reminded that gastroesophageal reflux disease (GERD) is common among asthmatic children and can trigger pulmonary symptoms that respond to anti-reflux therapy.24 Such patients often have been misdiagnosed as having "steroid-resistant" asthma.25 And, last but not least, an old standby, theophylline, of dubious benefit in mild asthma, recently has been demonstrated to hasten recovery from severe status asthmaticus among 47 children in a St. Louis pediatric intensive care unit (PICU), with more pronounced effects among intubated patients.26
Conclusion
Pediatric asthma remains an unsolved challenge today, with frustration, confusion, and heartbreak galore for families and physicians. Despite a panorama of proven therapies, preventive strategies, and novel new interventions, symptomatic children, school absenteeism, ED visits, hospital and PICU admissions, and death are far too frequent. As one researcher observed, we seem to be in the midst of "an epidemic in the absence of infection."27 ED staff need frequent updates on late-breaking research into this baffling syndrome—one which seems able to defy the aggregate efforts of monumental medical experts.28 I am convinced from my own practice, and from this review, that the wheezy child may not be the easy child in the ED.
Dr. Felz, Associate Professor, Department of Family Medicine, Medical College of Georgia, Augusta, is on the Editorial Board of Emergency Medicine Alert.
References
1. Busse WW, et al. Asthma. N Engl J Med 2001;344:350-362.
2. Szefler SJ. Challenges in assessing outcomes for pediatric asthma. J Allerg Clin Immunol 2001;107: S456-S464.
3. Naspitz CK, et al. Barriers to measuring and achieving optimal outcomes in pediatric asthma. J Allerg Clin Immunol 2001;107:S482-S484.
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5. Diette GB, et al. Consistency of care with national guidelines for children with asthma in managed care. J Pediatr 2001;138:59-64.
6. Cabana MD, et al. Barriers pediatricians face when using asthma practice guidelines. Arch Pediatr Adolesc Med 2000;154:685-693.
7. Mahabee-Gittens EM, et al. Are pediatric ED physicians blowing off peak expiratory flows? Am J Emerg Med 2000;18:352-353.
8. Bisgaard H, et al. Leukotriene modifiers in pediatric asthma management. Pediatrics 2001;107:381-390.
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11. Tien I, et al. Metered dose inhaler: The emergency department orphan. Arch Ped Adolesc Med 2001;155: 1335-1339.
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13. Goodman DC, et al. Has asthma medication use in children become more frequent, more appropriate, or both? Pediatrics 1999;104:187-194.
14. Welch MJ. Who should take care of the child with asthma? The pediatrician or the allergist? J Asthma 1998; 35:1-5.
15. Roberts JS, et al. Acute severe asthma: Differences in therapies and outcomes among pediatric intensive care units. Crit Care Med 2002;30:581-585.
16. Querishi F, et al. Comparative efficacy of oral dexamethasone versus oral prednisone in acute pediatric asthma. J Pediatr 2001;139:20-26.
17. Gawchik SM, et al. The safety and efficacy of nebulized levalbuterol compared with racemic albuterol and placebo in the treatment of asthma in pediatric patients. J Allerg Clin Immunol 1999;103:615-621.
18. Hendriks H, et al. Handling of a spacer (Babyhaler) for inhalation therapy in 0-3 year old children. J Asthma 1998;35:297-304.
19. Adams RJ, et al. Impact of inhaled anti-inflammatory therapy on hospitalization and emergency department visits for children with asthma. Pediatrics 2001;107: 706-711.
20. Zorc JJ, et al. Ipratropium bromide added to asthma treatment in the pediatric emergency department. Pediatrics 1999;103:748-752.
21. Rowe BH, et al. Intravenous magnesium sulfate treatment for acute asthma in the emergency department: A systematic review of the literature. Ann Emerg Med 2000;36:181-190.
22. Ciarallo L, et al. Higher dose intravenous magnesium therapy for children with moderate to severe acute asthma. Arch Pediatr Adolesc Med 2000;154:979-983.
23. Wilson SR, et al. A controlled trial of an environmental tobacco smoke reduction intervention in low income children with asthma. Chest 2001;120:1709-1722.
24. Goldenhersh MJ, et al. Asthma and gastroesophageal reflux in infants and children. Immunol Allerg Clin N Am 2001;21:439-448.
25. Spahn JD, et al. Steroid resistant asthma. Immunol Allerg Clin N Am 2001;21:569-588.
26. Ream RS, et al. Efficacy of IV theophylline in children with severe status asthmaticus. Chest 2001;119: 1480-1488.
27. Altemeier WA III. Asthma: Something is wrong. Pediatr Ann 1999;28:14-15.
28. Baren JM, et al. Contemporary approach to the emergency department management of pediatric asthma. Emerg Med Clin N Am 2002;20:115-138.
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