Normal saline for children with bronchiolitis: study protocol for a randomised controlled non-inferiority trial.

INTRODUCTION: Bronchiolitis is one of the most common reasons for hospital admissions in early childhood. As supportive treatment, some treatment guidelines suggest using nasal irrigation with normal saline (NS) to facilitate clearance of mucus from the airways. In addition, most paediatric departments in Denmark use nebulised NS for the same purpose, which can mainly be administered as inpatient care. However, no studies have ever directly tested the effect of saline in children with bronchiolitis. METHODS AND ANALYSIS: The study is an investigator-initiated, multicentre, open-label, randomised, controlled non-inferiority trial and will be performed at six paediatric departments in eastern Denmark. We plan to include 300 children aged 0-12 months admitted to hospital with bronchiolitis. Participating children are randomised 1:1:1 to nebulised NS, nasal irrigation with NS or no saline therapy. All other treatment will be given according to standard guidelines.The primary outcome is duration of hospitalisation, analysed according to intention-to-treat analysis using linear regression and Cox regression analysis. By including at least 249 children, we can prove non-inferiority with a limit of 12 hours admission, alpha 2.5% and a power of 80%. Secondary outcomes are need for respiratory support with nasal continuous positive airway pressure or high-flow oxygen therapy and requirement of fluid supplements (either by nasogastric tube or intravenous). ETHICS AND DISSEMINATION: This study may inform current practice for supportive treatment of children with bronchiolitis. First, if NS is found to be helpful, it may be implemented into global guidelines. If no effect of NS is found, we can stop spending resources on an ineffective treatment. Second, if NS is effective, but nasal irrigation is non-inferior to nebulisation, it may reduce the workload of nurses, and possible duration of hospitalisation because the treatment can be delivered by the parents at home. TRIAL REGISTRATION NUMBER: NCT05902702.