Gum Chewing, Added to Conventional Feeding, Reduces Risk of Post-Operative Ileus after Elective Hip and Knee Arthroplasty Procedures in Elderly Population: A Protocol for a Parallel Design, Open-Label, Randomized Controlled Trial.

Introduction: Postoperative ileus (poi) is defined as a temporary cessation of bowel movement after a surgical procedure. Cessation of bowel movement not only leads to disturbing constipation but also may lead to nausea, loss of appetite, and food intolerance. Literature reports "sham feeding" (gum-chewing) effect as an increase in chewing and saliva which enhances the gastric emptying and overall motility of gut as a cephalic phase of digestion. Therefore, we aim to assess the effect of adding gum-chewing to the conventional postoperative feeding regimen on restoring postoperative bowel function and length of stay in hospital of patients undergoing elective hip arthroplasty.

Methods and analysis: This is a single-center, open-label, parallel design, superiority randomized-controlled trial with 2 treatment arms. The primary and secondary outcomes will be the time interval in hours from the end of surgery until the passage of flatus and the time interval in hours from the end of surgery until the passage of stool. Statistical analysis will be done using STATA software. Length of stay will be calculated by Kaplan-Meier analysis, with unadjusted comparison of groups by Mantel-Cox log rank test. Risk ratios for the time-to-become ileus free and time-to-discharge from hospital will be calculated by Cox regression modeling. P value as 0.05 or less will be taken as significant.

Ethics and dissemination: This protocol is exempted from Ethical review at this stage however all the required approvals will be taken from the ethical review committee before starting the study. Informed consent will be taken form the patient to enroll him/her in the study. Results of the study will be disseminated to the study participants, public health, and clinical professionals. The results would also be published in a reputable international journal.

Trial registration: This trial is registered on clinicaltrials.gov with ID: NCT04489875.

Highlights: Cessation of bowel movement not only leads to disturbing constipation but also may lead to nausea, loss of appetite, and food intolerance.These patients tend to have more pain scores and dissatisfaction with the surgical management and team.The "sham feeding" (gum-chewing) effect causes an increase in chewing and saliva formation and therefore enhances the gastric emptying and overall motility of gut as a cephalic phase of digestion even in non-gastro or colorectal surgeries.We hypothesize that there is an association between gum chewing and the relief from postoperative ileus in hip arthroplasty patients.