A Study On Esophageal Mean Nocturnal Baseline Impedance In The Diagnosis And Treatment Of Gastroesophageal Reflux Disease

Objective: the analysis on the variation characteristics of multichannel intraluminal esophageal mean nocturnal baseline impedance(MNBI)in patients with gastroesophageal reflux disease(GERD)during 24-hour multichannel intraluminal impedance and pH monitoring(24h MII-pH monitoring),the application of MNBI in the diagnosis and treatment of GERD was investigated.Methods: 383 patients who underwent 24 h MII-pH monitoring due to the suspected diagnosis of GERD from January 2016 to December 2018 met the inclusion criteria,all of who completed symptom assessment,proton pump inhibitor(PPI)efficacy evaluation,and gastroscopy.222 patient with definite GERD of them were grouped according to the internal and external esophageal symptoms,PPI efficacy,endoscopic esophagitis performance,reflux parameters and other characteristics,and analyzed the changes in esophageal MNBI of 3,5,7,9,15 and 17 cm above the loweresophageal sphincter(LES)(corresponding to channels Z6,Z5,Z4,Z3,Z2 and Z1).Moreover,161 non-GERD patients were used as controls to analyze the change characteristics of MNBI.Results:(1)The Z1-Z6 esophageal MNBI values of GERD patients were significantly lower than those of non-GERD patients(P<0.05).(2)The distal MNBI values in reflux esophagitis(RE)was significantly lower than in non-erosive reflux disease(NERD)patients(P<0.05);GERD patients with extraesophageal symptoms(EES)had significantly lower proximal MNBI values than those with typical reflux syndrome(TRS)(P<0.05);In GERD questionnaire(GredQ)and reflux symptom index(RSI),the more severe the symptom,the lower the corresponding MNBI values,and the differences were statistically significant(P<0.05).(3)Acid exposure time(AET)was significantly negatively correlated with distal MNBI values(r=-0.33,P<0.0001),and positively correlated with acid reflux times.Distal MNBI values were significantly negatively correlated with acid reflux times and weakly acid reflux times;while proximal MNBI values were significantly negatively correlated with weakly acid reflux times and had no relationship with acid reflux times.(4)Best cutoff values of proximal and distal esophageal MNBI were 1766.0? and 2375.6? for distinguishing GERD patients respectively,the corresponding sensitivity was 22.9% and 51.8%,and the specificity was 93.7% and 92.5%,respectively,there were no statistical differences in specificity,but distal MNBI value had a highersensitivity(P<0.05).Current diagnostic GERD parameters(AET;DeMeester score;number of reflux episodes)combined with MNBI could improve the diagnosis rate of GERD in 24 h MII-pH monitoring,especially the distal MNBI values,with a sensitivity of 85.6%.(5)Negative correlations were observed between the proximal and distal MNBI values and PPI efficacy(P<0.001).Conclusion: MNBI values in all esophageal channels of GERD patients was significantly lower than that of non-GERD patients.The proximal and distal MNBI values were decreased to different degrees with different clinical characteristics in patients with GERD.Distal MNBI values was significantly negatively correlated with AET.Dital MNBI values(2375.6 ?)combined with current diagnostic GERD parameters(AET;DeMeester score;number of reflux episodes)could obviously improve the diagnosis rate of GERD in 24 h MII-pH monitoring.The decline in the degree of esophageal MNBI could help predict PPI efficacy.