CLINICAL QUESTION: Are corticosteroids effective in the treatment of croup?
BACKGROUND: Croup (laryngotracheobronchitis) is a common upper respiratory illness in children. Although it is often self-limiting, croup can cause significant morbidity and be costly to health care systems because of frequent visits to physicians or emergency departments and hospitalizations. The customary therapy of humidified air has only anecdotal benefits, and the evidence for racemic epinephrine shows only temporary relief at best.
POPULATION STUDIED: The 24 trials in this analysis included children 4 months to 12 years of age (mean ages ranged from 13 to 45 months). The authors of 14 trials studied inpatients (1375 patients), and 10 were conducted in emergency departments (846 patients).
STUDY DESIGN AND VALIDITY: This was a well-executed meta-analysis in which the authors combined the results of 24 randomized controlled trials that examined the effectiveness of corticosteroids for children with croup. Ninety-seven studies were initially identified by searching MEDLINE (1966 to 1997), EMBASE (1974 to 1997), and The Cochrane Controlled Trials Register of The Cochrane Library, as well as by corresponding with the authors of trials published in the previous 5 years. Studies were selected if 2 reviewers independently judged that these randomized controlled trials compared a corticosteroid with placebo or an active control and used a clinically important outcome. Seventy-three trials were excluded from analysis for appropriate reasons. Two independent reviewers blinded to author and study location assessed the quality of included trials using a validated 5-point scale. Systemic dexamethasone (Decadron) and nebulized budesonide (Pulmicort) were the most commonly studied drugs.
OUTCOMES MEASURED: Scores on scales measuring severity of croup symptoms, use of additional interventions, length of stay in the emergency department or hospital, and hospitalization rates were the main outcomes evaluated in this analysis. The 17-point Westley Clinical Croup Scale was the most frequently used outcome measure (13 studies). Other nonvalidated scoring systems were used in 5 studies, while 6 studies did not report a clinical croup score. Trial effect sizes were used in the pooled analyses because of inconsistency in the reporting of croup scores.
RESULTS: A significantly greater decrease in croup symptoms was noted after 6 and 12 hours of treatment with corticosteroids compared with treatment with placebo or a nonsteroid control. At 6 hours, this difference resulted in an average 15% improvement in symptom scores (95% confidence interval [CI], 2%-28%) with a number needed to treat (NNT) of 7. At 12 hours, the difference was 21% (95% CI, 9%-33%) with an NNT of 5.
In this well-executed meta-analysis corticosteroids were shown to have a small but clinically important beneficial effect on croup symptoms. The most frequently studied agents were inhaled budesonide and systemic dexamethasone. The authors were unable to compare different corticosteroids, doses, and routes of administration. These results are similar to those of a meta-analysis performed 10 years ago.1 Treatment of 5 children with croup with steroids will result in symptom improvement in one of them within 12 hours (NNT = 5). Additionally, use of these drugs decreases the need for additional interventions and the length of stay in the emergency department or hospital. The size of the effect is small and is perhaps overestimated. However, the low cost and low risk of these drugs make them worth a try in the acute management of this common problem.