Dosing of Steroids for Acute Asthma Given in the Emergency Department - a Pilot Randomised Feasibility Trial of Dexamethasone in Children

Asthma is the most common chronic condition to affect children, with approximately 1.1 million children treated for asthma in the UK. Hospital episode statistics confirm that emergency department (ED) attendances for exacerbations of asthma have risen over the past year, and accounts for a significant number of ED attendances and hospital admissions. Nearly 1000 children attended the ED at Sheffield Children's Hospital for asthma in 2022-23, with almost half requiring admission.

Steroids/glucocorticoids are first line treatments for acute exacerbations of asthma. The anti-inflammatory action of steroids reduces the airway oedema and secretions associated with acute asthma exacerbations, and their effects may be noted within two to four hours of administration. Traditionally, oral prednisolone has been the treatment used most widely. Prednisolone given orally is often vomited by the child and needs to be taken for 3-5 days. Dexamethasone is an alternative steroid which is better tolerated and due to its long duration of action can be used as a single dose given in the ED. Studies comparing prednisolone and Dexamethasone have demonstrated that Dexamethasone is non-inferior to Prednisolone in the treatment of asthma exacerbations (1,2). A systematic review found no differences between the two steroids in terms of hospital admission rates, time spent in the ED or relapse events, however children receiving Dexamethasone experienced lower noncompliance and vomiting rates. (3) Practically, use of dexamethasone allows simplification of treatment in EDs and improves flow as children do not have to wait for discharge medication. Treatment with Dexamethasone is more cost effective and treatment adherence is better.

In a survey of 37 UK EDs undertaken by the study team, 19 departments currently use Prednisolone, and 18 use Dexamethasone. Of the latter, 7 use 600 micrograms/kg and the other 11 use 300 micrograms/kg. The currently used dose at our institution is 600 micrograms/kg. The dose of dexamethasone used as oral treatment for exacerbations of asthma is not well established, as demonstrated by the survey and this reflects the studies which sought to compare Prednisolone with Dexamethasone which used different doses and routes. (4-6) While systemic steroids are an effective and safe treatment, there is a dose-dependent profile of side effects, hence the lowest effective dose should be used. This is even more important given concerns over side effects from even shorter courses of steroids as used in asthma (7). Dexamethasone is well established in the treatment of other acute paediatric respiratory conditions, such as croup, with evidence demonstrating that lower doses (150micrograms/kg) are safer, and equally as effective as higher doses (600 micrograms/kg) in this condition. (8, 9) The investigators hypothesise that using a lower dose of Dexamethasone (300 micrograms/kg) is not inferior to the 600 microgram/kg dose in the treatment of acute asthma. The effectiveness of treatment can be measured as length of stay in hospital or time to improvement in respiratory distress severity scores, however both of these can be subjective. Need for re-treatment with steroids is a pragmatic surrogate of efficacy of treatments as well as the need for further unscheduled medical care in children with asthma exacerbations. In our patient and parent involvement work for this study, parents have agreed that this outcome is important. They also want to be reassured that an effective dose is being given but are supportive of the study's objective and think it an important research question.

The investigators hypothesise that children treated with either dose of dexamethasone have a similar rate of retreatment with oral steroids (dexamethasone or prednisolone) for their asthma exacerbation.