Normal Values Of24-hour Combined Esophageal Multichannel Intraluminal Impedance And PH Monitoring And The Study Of Its Affecting Factors

Background and objective:The technology of the24-Hour combined esophageal Multichannel IntraluminalImpedance and PH Monitoring can distinguish between acidic reflux, weakly acidicreflux and weakly alkaline reflux; distinguish the changes of reflux from swallow. Itcan monitor the height of reflux and distinguish between liquid reflux, gas reflux andmixed reflux. This technology can be mainly used for gastroesophageal reflux disease.With the improvement of gastroesophageal reflux disease incidence, this technologybecomes more and more usefully in clinical. But now the normal values of thistechnology is still in question. The objects of this study were to define the range ofthe normal values of the24-hour combined esophageal multichannel intraluminalimpedance and pH Monitoring technology and to investigate the influence of age、posture and gender.Method:Through the recruitment of selected asymptomatic volunteers, medicalexaminations were implemented under endoscopy and high resolution esophagealimpedance manometry. After the exclusion of organic disease and esophagealmotility disorders, the selected asymptomatic were all underwent by the technologyof the24-Hour combined esophageal multichannel intraluminal impedance and pHmonitoring. Acidic reflux times, weakly acidic reflux times, weakly alkaline refluxtimes, liquid reflux times, gas reflux and mixed reflux times, the median of bolusclearance time,the median of acid clearance time, the percent time of reflux-relatedacid exposure,and proximal extent reflux times were recorded. The median ofproximal bolus clearance time was also computedd. The influence of age and genderwere also analyzed.Results:Ninety-seven healthy volunteers were recruited, including38cases of male and 59cases of female. The total refluxes in this study were (median24（14-40-62）,52%of which were weakly acdic reflux (median13(7-19-32),43%were acdic reflux(median10（2-18-35）,5%were weakly alkaline reflux(median0（0-1-11）.52%ofreflux episodes were mixed reflux (median15（9-24-42）,32%were liquid reflux(median9（5-15-26）),16%were gas reflux (median5（2-8-13）).27%of refluxepisodes were proximal extent reflux (median5（2-10-22）,59%of which were acdicreflux (median2（0-7-16),39%were weakly acdic reflux (median2（1-4-11）,2%were weakly alkaline reflux (median0（0-0-2）.The acid clearance time were(median23（11-31-75）s, while reflux clearance time were10（7-13-19）s. Themedian of proximal bolus clearance time was6s.Acid clearance time is longer thanbolus cleaance time,which is about2.3times. Upright position was more than supinewithin all the reflux. Sex differences between male and female in the total number ofreflux episodes were evident in following indicators: the number of acidic reflux,weakly acidic reflux episodes, liquid reflux, mixed reflux, proximal reflux, proximalacid reflux, proximal weakly acidic reflux,reflux clearance time and reflux-relatedacid exposure. Esophageal impedance baseline value had no significant differencebetween male and female in this study. No significant difference of baselineimpedance has been observed between the age group under and above30-year-old.Conclusion:The normal range of the24-hour combined esophageal multichannelintraluminal impedance and pH monitoring were established through the study ofNinety-seven cases of healthy volunteers. The range of normal values is less than thestudy of previous studies, Significant difference of which has been observed betweendifferent gender and different postures. But no difference of esophageal impedancebaseline has been observed between the sex and age.