Analyses of the relationship between a "number of reflux episodes' exceeding 70 and the pH index in neurologically impaired children by evaluating esophageal combined pH-multichannel intraluminal impedance measurements

Background: The present study aimed to evaluate the characteristics associated with a number of reflux episodes (NoRE) of 70 by comparing the clinical and multichannel intraluminal impedance pH measurements (pH/MII) and pH index (pHI) in neurologically impaired (NI) children.Patients and methods: NI children (1-16 years of age) in whom pH/MII had been measured for GERD study were enrolled in this study. All children were divided into NoRE>70 or 70 and pHI>4.0 or 4.0, >5.0 or 5.0 or >7.0 or 7.0. In addition, the NI children with pHI>4.0,>5.0 and>7.0 were subdivided into NoRE>70 and70 groups. The clinical and pH/MII measurements were compared between each of the two groups. The cutoff values of pHI and baseline impedance (BI) (Z6) were calculated to discriminate NoRE>70 and70.Results: A total of 61 NI children were enrolled in this study. There was a significant difference in the acid-related parameters, the NoRE (nonacid) and BI between NoRE>70 and70, acid-related parameters and BI between pHI>4.0 and4.0,>5.0 and 5.0 and >7.0 and 7.0 groups. Furthermore, a significant difference was still observed in the BI between NoRE >70 and 70 groups among patients with pHI >4.0,>5.0 or>7.0. The cutoff values of pHI and BI (Z6) for discriminating NoRE >70 and 70 were 9.2 and 1049, respectively.Conclusion: The present study indicates that NoRE 70 corresponds to GERD in which patients suffer severe acid exposure with pH of around 9% and esophageal mucosal damage with low BI value in NI children.