Introduction: High-flow nasal cannula (HFNC) is a non-invasive form of respiratory support used increasingly in bronchiolitis. HFNC provides a variable amount of positive pressure similar to continuous positive airway pressure (CPAP). The positive pressure in CPAP can distend and loosen oesophageal sphincter pressure leading to increased reflux. It is unclear if HFNC causes a similar action. Feeding tubes are used to provide nutrition and hydration to patients that are unable to safely take oral feedings. If there is increased reflux from HFNC, this would increase the risk of aspiration. Our institution places nasoduodenal tubes (NDT) to eliminate this risk. The purpose of the study is to infer if there is a difference between NDT and nasogastric tube (NGT) feeding with regard to length of respiratory support, number of emesis, number of chest X-rays and readmission/emergency room revisit rates., Methods and Analysis: Patients with bronchiolitis, on high-flow nasal cannula, and whose primary physicians have decided on feeding tube for nutrition/hydration will be approached for consent and enrolment. Patients will be randomised to NGT or NDT in variable block sizes and stratified into low- and high-risk groups. Outcomes will be analysed by both a frequentist and Bayesian statistical approach., Ethics and Dissemination: The trial was approved by local institutional review board. Every attempt will be made to reduce to an absolute minimum the interval between completion of data collection and release of study results through appropriate dissemination mediums including abstracts, poster presentations and journal publications., Trial Registration Number: NCT03346850; Pre-results., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2018. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)