S1900 EGJ pH Mapping: A Novel Model for Esophageal pH Monitoring Not Preceded By Lower Esophageal Sphincter Manometry

Abstract

There are patients with reflux symptoms who have physiologic acid reflux and positive index symptom (PSI). By pH-multichannel intraluminal impedance (pH-MII) it is possible to detect abnormal non-acid gastro esophageal reflux, this reflux can explain the presence of symptoms and might allow us to classify the patients as carriers of gastroesophageal reflux disease, even if they have physiologic acid reflux. Our objective was to investigate characteristics of esophageal pH-MII in patients with physiologic acid reflux and PSI and to know how often non acid reflux is related to PIS. Cross-sectional study in adults whose results of pH-MII showed physiologic acid reflux and PSI.Divided into two groups: physiologic acid reflux and PSI and physiologic acid reflux and negative symptoms index (NSI).We analyzed DeMeester score, 24 hours acid exposure, total time of exposure to acid bolus, upright and recumbent exposure to acid bolus, total number of non-acid reflux events and, symptoms index for acid and non-acid reflux. For comparison between groups we used U Mann-Withney Test and for the analysis of proportions X2. Results:We included 50 patients. In group A there were 29 patients with a mean 24 hours acid exposure of 1.71% (0-5%), DeMeester score 5.2 (0.8-14.6). The total time of exposure to acid bolus, upright and recumbent exposures to acid bolus were 8 min (1%), 9.7min (1.7%) and 1.7 min (0.26%).In these patients total number of reflux events had a mean of 57.89 (16-182) of which, 24.04 (1-55) and 16 (1-160) were acid and nonacid respectively. In this group 62% (18) had PSI to acid reflux, 27.5% (8) PSI to non-acid reflux and, 10.3% (3) PSI to both. In group B there were 21 patients with a mean 24 hours acid exposure of 0.78% (0-3.6%), DeMeester Score 2.7 (0.8-11.8) and total number of reflux events of 32.2 (3-91) of which, 12.81 (150) and 12(0-77) were acid and nonacid respectively. The total time of exposure to acid bolus, upright and recumbent exposures to acid bolus were 3 min (0.41%), 3.5 min (0.67%), 0.6 (0.13%) respectively. In total there were 7 patients with more than 73 episodes of reflux in 24 hours, 4 in group A and 3 in group B respectively. When both groups were compared there were higher values of 24 hours acid exposure, DeMeester score, total and upright exposure to acid bolus in group A (p=0.002). Conclusions: We found that only in 27.5% of patients with physiologic acid reflux the presence of non acid reflux is related to symptoms.That means acid is still responsible for symptoms in the remaining patients.