Dexamethasone in bronchiolitis: a randomised controlled trial

Summary

Background

Although corticosteroids are commonly prescribed in the treatment of bronchiolitis, there is no evidence on the efficacy of these drugs in this disorder. We designed a randomised, double-blind, prospective study to assess the efficacy of dexamethasone in infants with bronchiolitis who require hospital management.

Methods

Infants younger than 12 months who had been admitted to hospital for an initial episode of wheezing, were randomly allocated intramuscular dexamethasone (1 mg/kg daily) or placebo, every 24 h for three doses. We excluded infants who were younger than 4 weeks, who required admission to the intensive care unit, or who had a history of congenital heart disease, mechanical ventilation, or supplemental oxygen use. We assessed infants on admission and every 12 h thereafter—vital signs were taken, severity of accessory muscle use and wheezing were measured by a clinical severity score, and pulse oximetry in room air was done. Our primary endpoints were the time to resolution of symptoms—defined as the number of assessments needed to reach oxygen saturation of more than 95% while receiving no supplemetal oxygen, an accessory muscle score of 0, a wheeze score of 0 or 1, and resumption of normal feeding—and duration of oxygen therapy. Follow-up assessments were made 10–14 days after discharge by telephone. We used a proportional-hazards model for our survival analysis.

Findings

197 infants presented with bronchiolitis that required inpatient management. 75 were not enrolled (31 no consent, 28 no approach made, 16 transferred elsewhere). Of the 122 enrolled, four were excluded (clinical deterioration, diagnosis of cystic fibrosis, previous intubation, did not receive all study treatment). There were no differences between the dexamethasone (n=65) and placebo-treated infants in demographic factors, exposure to tobacco smoke, duration of illness, presence of respiratory syncytial virus (RSV) antigen, respiratory rate, or severity score. More dexamethasone-treated patients had an initial oxygen saturation of 95% or less (51 [79%] dexamethasone vs 31 [59%] placebo, p=0·02). There were no differences in duration of oxygen therapy (p=0·74) or time to resolution of symptoms (p=0·22). Stratification for presence of RSV antigen or family history of atopy did not affect the results.

Interpretation

Our findings do not support the use of dexamethasone in the treatment of bronchiolitis in infants.

Introduction

Bronchiolitis is an infection of the lower respiratory tract that occurs during the first 12 months of life and is characterised by wheezing. Bronchiolitis is most commonly associated with respiratory syncytial virus (RSV) and is the most frequent cause of hospital admission for infants during the winter months.¹ The disorder has several clinical and pathophysiological similarities to asthma, and since many infants with bronchiolitis wheeze, even after recovery,2, 3, 4 many clinicians use conventional asthma therapy for infants with bronchiolitis.

Corticosteroids are effective anti-inflammatory drugs for the treatment of asthma.⁵ Their usefulness in bronchiolitis has also been investigated, but previous trials have been limited by differences in definitions of bronchiolitis, lack of specific exclusion criteria, reliance on subjective assessments, and lack of objective measurements of hypoxaemia.6, 7, 8 Although there is no convincing evidence on the safety and efficacy of corticosteroids, physicians commonly prescribe these drugs in the treatment of bronchiolitis.9, 10 Review of medical records at our institution showed that 47% of previously healthy children, aged younger than 12 months, who were admitted with a diagnosis of bronchiolitis had been prescribed corticosteroids.

The aim of our prospective, randomised, double-blind study was to assess the efficacy and safety of corticosteroids in the treatment of bronchiolitis while addressing the shortcomings of previous studies.