High-flow nasal cannula versus standard oxygen therapy assisting sedation during endoscopic retrograde cholangiopancreatography in high risk cases (OTHER): study protocol of a randomised multicentric trial.

Endoscopic retrograde cholangiopancreatography (ERCP) is an increasingly common intervention in the treatment of pancreaticobiliary disorders. Patients are often elderly with complex co-morbidities. While monitored anaesthesia care with sedation is commonly used for most cases, few would require general anaesthesia with an endotracheal tube. Both low-flow and high-flow nasal cannulas (HFNC) are established ways of delivering supplemental oxygen, but it is unclear whether one technique is better than the other. HFNC seems a promising tool for advanced procedures but evidence to support its application in high-risk ERCP cases is limited. The rate of oxygen desaturation during endoscopy has been reported to be as high as 11%–50% and the method of oxygen delivery for ERCP merits further study. This is a prospective, randomised, multicentre trial comparing the efficacy of oxygen supplementation through HFNC versus low-flow nasal cannula during ERCP, in a cohort of patients at risk of adverse respiratory events. A total of 132 patients will be recruited across three sites and randomly assigned to either the low-flow or the HFNC group. The primary outcome is the proportion of patients experiencing hypoxia, defined by any event of SpO2 < 90%. The secondary outcomes include parameters centred on oxygenation, requirement of airway manoeuvres, successful completion of procedure, perioperative complications, patient satisfaction and cost analysis of the consumables. An intention-to-treat principle will be applied while analysing. The demand for ERCPs is likely to increase in the future with the aging population. Our study results may lead to improved outcomes and reduce airway-related complications in patients undergoing ERCPs. The results will be presented at national and international meetings and published in peer-reviewed journals. www.ANZCTR.org.au, CTRN12619000397112. Registered on 12 March 2019.