P3233 - Non-Acid Reflux Predominance in the Upright Position: A Consciousness State Analysis in Refractory GERD Patients Using Impedance-pH and Actigraphy Data

Catherine Chang, MD¹, Gengqing Song, MD², Ronnie Fass, MD^3
1University of Pittsburgh Medical Center, Pittsburgh, PA; ²MetroHealth Medical Center, Case Western Reserve University, Cleveland, OH; ³MetroHealth System, Case Western Reserve University, Cleveland, OH

Introduction: Analysis of gastroesophageal acid reflux traditionally relied on body position, yet recent studies show differences in reflux characteristics between recumbent-awake and recumbent-asleep periods, and the influence of consciousness. Non-acid reflux accounts for one-third of all reflux events, yet its relation to consciousness has not been evaluated. The purpose of this study was to determine the principal reflux characteristics of non-acid reflux during the upright, recumbent-awake, and recumbent-asleep periods in patients with refractory gastroesophageal reflux disease (GERD) on proton pump inhibitor (PPI) therapy.

Methods: Patients with documented GERD at baseline and persistent reflux symptoms despite PPI twice daily therapy were included. All subjects were at least 18 years old and underwent combined impedance-pH monitoring concomitantly with actigraphy. Parameters analyzed included: mean duration of sleep time (min); mean percentage total time pH < 4 (acidic), pH 4-6.9 (weakly acidic), and pH ≥7 (weakly alkaline); frequency of reflux events (per h); and mean duration of a reflux event (min). Student t-tests were used to analyze continuous variables, and a P-value of < 0.05 was inferred as clinically significant.

Results: Twelve subjects (11 female, mean age 57.8±10.7 years) were included. The percent total time pH ≥7 was significantly higher in the upright period (11.23±19.40, P< 0.05) compared to the recumbent-awake period (1.52±4.72) with no significant difference between recumbent-awake and asleep periods (0.38±0.90, P=0.3). The mean number of weakly acidic reflux events per hour was significantly higher in the upright period (3.06±2.00, P< 0.01) compared to the recumbent-awake and recumbent-asleep periods (0.09±0.30 vs. 0.37±0.40, P=0.1). There were no weakly alkaline reflux events recorded during either recumbent-awake or asleep periods. The mean duration of weakly acidic reflux did not statistically differ among the three periods. Symptomatic non-acid reflux was reported in 25% of patients during the upright period.

Discussion: Weakly acidic and weakly alkaline reflux events primarily occur in upright periods, while being notably infrequent during recumbent-awake and asleep states. Our study provides valuable insight into the behavior of non-acid reflux in relation to varying states of consciousness, and highlights its predominance as an upright phenomenon less influenced by consciousness compared to acid reflux.


Disclosures:


Catherine Chang, MD¹, Gengqing Song, MD², Ronnie Fass, MD³. P3233 - Non-Acid Reflux Predominance in the Upright Position: A Consciousness State Analysis in Refractory GERD Patients Using Impedance-pH and Actigraphy Data, ACG 2023 Annual Scientific Meeting Abstracts. Vancouver, BC, Canada: American College of Gastroenterology.