Dexamethasone and bronchiolitis: A new look at an old therapy?
2002; Elsevier BV; Volume: 140; Issue: 1 Linguagem: Inglês
10.1067/mpd.2002.121691
ISSN1097-6833
Autores Tópico(s)Respiratory Support and Mechanisms
ResumoSee related article,p 27 . In this issue of The Journal, Schuh et al1Schuh S Coates AL Binnie R Allin T Goia C Corey M et al.Efficacy of oral dexamethasone in outpatients with acute bronchiolitis.J Pediatr. 2002; 140: 27-32Abstract Full Text Full Text PDF PubMed Scopus (139) Google Scholar challenge the widely, but not universally, held view that corticosteroids have no role in the treatment of previously well children with bronchiolitis. Few aspects of the treatment of infants with bronchiolitis have been studied as often or as well. First, corticosteroids are of unquestioned benefit for infants and young children with asthma and bronchopulmonary dysplasia, clinically similar wheezing illnesses. Second, while bronchiolitis, like asthma, is a common and apparently growing problem,2Shay DK Holman RC Newman RD Liu LL Stout JW Anderson LJ. Bornchiolitis-associated hospitalizations among US children, 1980-1996.JAMA. 1999; 282: 1440-1446Crossref PubMed Scopus (1173) Google Scholar the pediatrician's therapeutic armamentarium is remarkably thin. Ribavirin is available as specific treatment for infants with RSV (respiratory syncytial virus) infection, but its high cost and the absence of studies that address contentious issues of indications, environmental exposure of health care workers, potential side effects, and even efficacy, remain problematic. Some bronchodilators are of benefit to certain children with bronchiolitis, but they do not have a major effect on the overall course of the illness. The remaining treatments for infants with bronchiolitis are supportive. Physicians treating children with bronchiolitis and investigators studying its management need to recognize that an important subset of children with viral bronchiolitis, those with underlying airway diseases, benefit predictably from corticosteroid therapy. This is important because infants with underlying diseases like bronchopulmonary dysplasia or asthma may be at higher risk than previously well infants of developing respiratory failure with respiratory viral infections. A physician treating a child with bronchiolitis and respiratory compromise who also has underlying airway disease should strongly consider corticosteroid therapy regardless of the questionable efficacy of corticosteroids in previously well children with viral-associated wheezing. This issue may have influenced the conclusions of some studies of the efficacy of corticosteroids in bronchiolitis, including that of a recent meta-analysis by Garrison et al.3Garrison MM Christakis DA Harvey E Cummings P Davis RL. Systemic corticosteroids in infant bronchiolitis: a meta-analysis.Pediatrics. 2000; 105: e44Crossref PubMed Scopus (166) Google Scholar Several studies included in the meta-analysis that suggested that corticosteroid treatment is beneficial did not exclude children with previous episodes of wheezing. This problem, however, is not pertinent to the study of Schuh et al1Schuh S Coates AL Binnie R Allin T Goia C Corey M et al.Efficacy of oral dexamethasone in outpatients with acute bronchiolitis.J Pediatr. 2002; 140: 27-32Abstract Full Text Full Text PDF PubMed Scopus (139) Google Scholar, who did exclude such children. Schuh et al1Schuh S Coates AL Binnie R Allin T Goia C Corey M et al.Efficacy of oral dexamethasone in outpatients with acute bronchiolitis.J Pediatr. 2002; 140: 27-32Abstract Full Text Full Text PDF PubMed Scopus (139) Google Scholar found a benefit 4 hours after a single large dose of dexamethasone in 2 outcome variables: respiratory status as measured by a respiratory assessment change score (RACS) and hospitalization rate. Both parameters have strengths and weaknesses. The RACS is made on the basis of a clinical assessment tool that has previously been well validated. Hospitalization rate is a useful outcome variable because of the importance of bronchiolitis-associated hospitalization for the affected infant/family and for the health care system. Hospitalizations for RSV stress the family, challenge the resources of pediatric inpatient services during the yearly epidemic, and account for RSV's major economic cost to society. The likelihood that the statistically significant change in clinical status found was also clinically important is suggested by the associated decrease in the hospitalization rate. On the other hand, indications for hospitalization for infants with bronchiolitis are subjective and vary dramatically from area to area,4McConnochie KM Roghmann KJ Liptak GS. Hospitalization for lower respiratory tract illness in infants: variation in rates among counties in New York state and areas within Monroe County.J Pediatr. 1995; 126: 220-229Abstract Full Text Full Text PDF PubMed Scopus (61) Google Scholar physician to physician, and, potentially, with time through the epidemic. In fact, the clinical value of hospitalization for the majority of infants with RSV who do not have serious respiratory compromise is unclear. Most supportive therapies could be equally well provided at home and the risk of deterioration after hospitalization in most infants admitted is low.5Brooks AM McBride JT McConnochie KM Aviram M Long C Hall CB. Predicting deterioration in previously healthy infants hospitalized with respiratory syncytial virus infection.Pediatrics. 1999; 104: 463-467Crossref PubMed Scopus (67) Google Scholar Schuh et al1Schuh S Coates AL Binnie R Allin T Goia C Corey M et al.Efficacy of oral dexamethasone in outpatients with acute bronchiolitis.J Pediatr. 2002; 140: 27-32Abstract Full Text Full Text PDF PubMed Scopus (139) Google Scholar are to be congratulated for addressing an important aspect of bronchiolitis therapy with a welldesigned study. However, physicians should consider waiting before adding a single dose of dexamethasone to the routine treatment of previously well infants arriving at the emergency department with bronchiolitis. The authors present a number of possible explanations for the fact that they were able to demonstrate an effect of corticosteroid treatment, whereas many previous careful investigators have not. They treated infants upon arrival to the emergency department rather than somewhat later in their course, after admission. By enrolling outpatients, they probably studied a less severely affected population than studies that have enrolled inpatients. They used a larger dose of corticosteroid than many previous studies. However persuasive the findings of the present study, the thoughtful pediatrician would do well to maintain a healthy skepticism, particularly when the therapy of so many infants throughout the country and the world may be altered. Any change in therapy that affects so many patients demands careful consideration of potential side effects (even uncommon ones) and possible alternative explanations for experimental findings. The dose of dexamethasone used was large (1 mg/kg). Although the authors outline reasons that they chose this dose and that such a dose should be well tolerated, one wonders if the widespread use of this dose in the large population of infants that will meet criteria for treatment might result in an increased risk of serious bacterial superinfection in a small number of particularly susceptible individuals. Such a small risk might be justified if it were shown that early corticosteroid treatment prevented serious morbidity in children with bronchiolitis, but the majority of infants who require intensive care for RSV infection are already recognized as being critically ill when they arrive at the emergency department and so would not have been included in the present study.5Brooks AM McBride JT McConnochie KM Aviram M Long C Hall CB. Predicting deterioration in previously healthy infants hospitalized with respiratory syncytial virus infection.Pediatrics. 1999; 104: 463-467Crossref PubMed Scopus (67) Google Scholar There is a possibility that the effect of the dexamethasone observed was nonspecific. The authors argue that this treatment might have decreased airway edema within 4 hours. It is unlikely that there would be such an effect so soon. If resolution of airway edema was the mechanism, it would be surprising that such an effect would not also benefit infants later in their course, after admission. The antipyretic effect of corticosteroids needs to be taken into careful consideration by investigators planning to replicate the study of Schuh et al.1Schuh S Coates AL Binnie R Allin T Goia C Corey M et al.Efficacy of oral dexamethasone in outpatients with acute bronchiolitis.J Pediatr. 2002; 140: 27-32Abstract Full Text Full Text PDF PubMed Scopus (139) Google Scholar Nearly 60% of the corticosteroid treated patients were febrile at enrollment and dexamethasone is an antipyretic. Fever, through its effect on metabolic rate, increases minute ventilation. This is accomplished by an increase in respiratory rate, a component of the RACS, and an increase in respiratory effort as reflected in retractions, an important part of the Respiratory Disease Assessment Instrument. Dexamethasone might have benefitted the treated patients by decreasing fever rather than by affecting airway edema or some other specific aspect of airway obstruction. If so, alternative antipyretics would be preferred. Infants, their families, their physicians, and our health care system sorely need new and effective approaches to the management of bronchiolitis. Fortunately and unfortunately, there is no lack of patients available to researchers interested in investigating new (or old) therapies for this common illness. Studies to confirm the conclusions of Schuh et al1Schuh S Coates AL Binnie R Allin T Goia C Corey M et al.Efficacy of oral dexamethasone in outpatients with acute bronchiolitis.J Pediatr. 2002; 140: 27-32Abstract Full Text Full Text PDF PubMed Scopus (139) Google Scholar, that corticosteroids benefit previously well infants with bronchiolitis arriving at the emergency department, should be forthcoming. If a benefit of corticosteroid treatment in these infants is confirmed, further studies that document the absence of side effects in large numbers of patients and that define optimal dosing strategies should follow. Efficacy of oral dexamethasone in outpatients with acute bronchiolitisThe Journal of PediatricsVol. 140Issue 1PreviewObjective: To examine the efficacy of oral dexamethasone in acute bronchiolitis. Study design: A double-blind randomized, placebo-controlled trial involving 70 children <24 months old in the emergency department with Respiratory Disease Assessment Instrument ≥6. Each patient received either 1 dose of 1 mg/kg of oral dexamethasone or placebo and was assessed hourly for a 4-hour period. Repeated measures regression analysis evaluated a change in the Respiratory Assessment Change Score (RACS). Results: The 2 groups had similar baseline characteristics with Respiratory Disease Assessment Inventory of 9.4 ± 2.3 in the dexamethasone group (n = 36) and 10.0 ± 2.7 in the placebo group (n = 34). Full-Text PDF
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