For children with severe obstruction, nebulised adrenaline in a dose of mL/kg of a 1% solution or 4 mL of the 1:1000 preparation reduces subglottic oedema and appears to decrease the need for intubation, although the effect lasts only a few hours. Adrenaline may be given either as the racemic or L-adrenaline form. Any child, whether in a general practice setting or hospitalised, should receive adrenaline if they have marked stridor at rest with soft tissue recession. Due to the early dramatic and prolonged reduction in symptoms achieved by steroids, it is now rare to have to repeat nebulised adrenaline after the first hour.
We identified 19 eligible studies (3459 individuals), all observational; 13 studies (1917 individuals) were suitable for inclusion in the meta-analysis of mortality . Of these, 12 studied patients infected with 2009 influenza A H1N1 virus (H1N1pdm09). Risk of bias was greatest in the 'comparability domain' of the Newcastle-Ottawa scale, consistent with potential confounding by indication. Data specific to mortality were of very low quality. Reported doses of corticosteroids used were high and indications for their use were not well reported. On meta-analysis , corticosteroid therapy was associated with increased mortality ( odds ratio ( OR ) , 95% confidence interval ( CI ) to ). Pooled subgroup analysis of adjusted estimates of mortality from four studies found a similar association ( OR , 95% CI to ). Three studies reported greater odds of hospital-acquired infection related to corticosteroid therapy ; all were unadjusted estimates and we graded the data as very low quality.
Caveats: In the Cochrane review, glucocorticoid has been shown to reduce the revisits and/or (re)admission rates and to decrease epinephrine use as a rescue therapy. The seven trials in the ED show the most benefit of glucocorticoid, where the absolute risk difference is 10% (NNT = 10). In the inpatient setting this absolute risk difference was % (NNT = 15). The % absolute benefit in need for readmission (NNT=11) is impressive, but this is based on a 21% overall rate of readmission in children in the control groups in this review. The actual benefit for a child will depend upon how often croup children are readmitted at baseline in one’s institution. The Cochrane authors note that in their group of studies the average readmission rate among institutions was roughly 12%, which would suggest an average NNT of 17.
The Cochrane review examined other outcome measures, such as length of stay and clinical severity. The cumulative length of stay was shortened by glucocorticoids by just over 11 hours in the combined inpatient (8 trials) and outpatient (1 trial) trials. Leipzig (1979) was the sole ED trial, however these study patients were admitted to the inpatient floors.
Finally, glucocorticoid treatment reduced clinical severity as measured by Westley scores. Children have a better clinical outcome according to the Westley score at the 6-hour and 12-hour mark (- and - points, respectively). A score reduction of 1 unit from baseline is deemed to be clinically significant.
Overall, the Cochrane review suggests that 5 patients would need to be treated with glucocorticoid for 1 patient to experience some measurable clinical benefit. The benefits are lower Westley score, fewer visits and/or (re)admission, decreased length of stay, or decreased usage of epinephrine as rescue therapy.