Continuous Gastric pH Monitoring in Children Facilitates Better Understanding of Gastroesophageal Reflux Disease: A Prospective Observational Study

<b>Objectives:</b> Gastroesophageal reflux disease (GERD) is commonly encountered in adults and children. A subset of patients with GERD are refractory to acid suppressants, implicating other factors in the refluxate. Duodenogastric reflux (DGR) produces similar symptoms through reflux of non-acidic duodenal content and the cytotoxic effect of bile in the esophageal mucosa. Various methods have been utilized to detect DGR using a Bilitec device or Hepatobiliary scintigraphy, amongst the most common, each with their own limitations. We aimed to use combined multichannel intraluminal impedance and pH (MII-pH) monitoring with an additional gastric pH sensor to collect information about acidic and non-acidic gastroesophageal refluxes and to assess whether continuous gastric pH measurement in children provides indirect evidence of DGR for better understanding of the symptoms. <b>Methods:</b> From 2022 through 2023, clinically symptomatic pediatric patients scheduled for esophagogastroduodenoscopy (EGD) and MII-pH at Arnold Palmer Hospital for Children in the United States were included (n = 26). Exclusions included patients taking acid suppressants prior to the start of this study. The data were analyzed for subjects completing at least 18 h of the study protocol. <b>Results:</b> Subjects with a normal pH impedance (n = 5) showed a median non-meal gastric pH of 1.8. Subjects with an abnormal pH impedance (n = 21) showed a median non-meal gastric pH of 2.2. Of the 26 subjects enrolled, the duration of non-meal gastric pH 4.0-7.0 was positively correlated with non-acidic gastroesophageal refluxes. Although all acidic reflux events occurred at gastric pH < 4.0, there was no correlation between the duration of non-meal gastric pH < 4.0 and impedance changes or reflux index. <b>Conclusions:</b> The results showed daily variability in the non-meal gastric pH of pediatric patients and a statistically significant correlation between its duration at pH 4.0 to 7.0 and non-acidic refluxes suggestive of the implication of DGR. Further research is required to assess this association with gastroesophageal reflux and dyspeptic symptoms to investigate the diagnostic tools and therapeutic interventions, including the role of prokinetics and surface protective agents for DGR.