A rabbit model of clinically relevant mucosal injury induced by nasogastric tube intubation

Mucosal injury is a common complication in nasogastric tube (NGT) intubation and causes continuous pain and secondary inflammation in clinical practice. We developed a New Zealand rabbit model to elucidate the occurrence and progression of the mucosal injury in NGT intubation. To simulate the clinical intubation procedure, the NGT was blindly inserted from the nose to the stomach. We first investigated the impact of the NGT size on the intubation success ratio in the rabbit. The high success rate of intubation made the NGT of Fr/Ch6 an appropriate choice. The degree of mucosal injury along with the prolonged intubation time was assessed via laryngoscopy. Hematoxylin and eosin staining was performed to evaluate the extent of mucosal injury and inflammatory cell infiltration. The expression levels of proinflammatory cytokines including interleukin-1β (IL-1β), interleukin-8 (IL-8) and interleukin-6 (IL-6) in the injured mucosa were further determined using the qPCR and immunofluorescence analysis. Inserting the NGT caused obvious mucosal injuries at the nasal concha and nasal septum of the rabbit. The nasal septum mucosa showed the most severe injury and was featured by apparent redness, ulcer bleeding and severe exfoliation of epithelial cells. The secondary inflammatory response including inflammatory cell infiltration and proinflammatory cytokines expression (IL-1β, IL-8, and IL-6) in nasal septum mucosa gradually aggravated with the increasing intubation time. Our model offers a valuable and reliable experimental platform for developing novel NGTs, advanced intubation techniques and effective clinical treatments.