PurposeTo determine whether erythromycin is non-inferior to metoclopramide in facilitating post-pyloric placement of self-propelled spiral nasoenteric tubes (NETs) in critically ill patients.MethodsA prospective, multicenter, open-label, parallel, and non-inferiority randomized controlled trial was conducted comparing erythromycin with metoclopramide in facilitating post-pyloric placement of spiral NETs in critically ill patients admitted to intensive care units (ICUs) of eight tertiary hospitals in China. The primary outcome was procedure success defined as post-pyloric placement (spiral NETs reached the first portion of the duodenum or beyond confirmed by abdominal radiography 24 h after tube insertion).ResultsA total of 5688 patients were admitted to the ICUs. Of these, in 355 patients there was a plan to insert a nasoenteric feeding tube, of whom 332 were randomized, with 167 patients assigned to the erythromycin group and 165 patients assigned to the metoclopramide group. The success rate of post-pyloric placement was 57.5% (96/167) in the erythromycin group, as compared with 50.3% (83/165) in the metoclopramide group (a difference of 7.2%, 95% CI − 3.5% to 17.9%), in the intention-to-treat analysis, not including the prespecified margin of − 10% for non-inferiority. The success rates of post-D1 (reaching the second portion of the duodenum or beyond), post-D2 (reaching the third portion of the duodenum or beyond), post-D3 (reaching the fourth portion of the duodenum or beyond), and proximal jejunum placement and the incidence of any adverse events were not significantly different between the groups.ConclusionsErythromycin is non-inferior to metoclopramide in facilitating post-pyloric placement of spiral NETs in critically ill patients. The success rates of post-D1, post-D2, post-D3, and proximal jejunum placement were not significantly different.