D0200 - The Use of Mean Nocturnal Baseline Impedance for Aiding in Reflux Disease Diagnosis and Etiology Evaluation

Carter Edmunds, BS¹, Steven Clayton, MD, FACG², Chaewon Jeong, BS^1
1Wake Forest University School of Medicine, Winston-Salem, NC; ²Atrium Health Wake Forest Baptist, Winston-Salem, NC

Introduction: Traditional parameters for reflux disease evaluation are often limited in their diagnostic value when evaluating the etiology of the reflux. We used a novel parameter, mean nocturnal baseline impedance (MNBI), to determine if this value can help further characterize the reflux disease. The aim of our study was to determine if the MNBI value could be used to delineate the diagnosis of pathological GERD from functional heartburn in patients with possible non-erosive reflux disease (NERD) and to evaluate how well the MNBI value correlates with erosive reflux disease (ERD) vs NERD.

Methods: We performed a retrospective study at a tertiary care, academic center in North Carolina of patients with gastroesophageal reflux symptoms who underwent an esophagogastroduodenoscopy (EGD) and 24 h multichannel intraluminal impedance-pH (MII-pH) testing from January 2018 to October 2021. Reviewers blindly analyzed EGD and MII-pH findings of 73 patients with confirmed ERD and 527 patients with non-erosive reflux disease evaluating for MNBI value, esophageal acid exposure time (AET), number of total reflux events, and the response to PPI therapy.

Results: The major findings of our study were that patients with normal total AET were more likely to have a normal MNBI value (p< 0.0001), with an abnormal MNBI value cutoff of 2.292 (kOhm), than pH-positive NERD patients as shown in Tables 1a-1b and 1e-1f. Additionally, an abnormal MNBI value helped predict which patients were pH-positive patients with erosive esophagitis when either total AET cutoff criteria were used (p< 0.0001) as shown in Table 1c-1d. In addition, patients with an abnormal MNBI value were more likely to be pH-positive NERD patients (p< 0.0001).

Discussion: Using the MNBI value increased the ability to determine if a patient with non-erosive reflux symptoms were more likely experiencing symptoms due to pathological GERD vs functional heartburn. This is due to patients with normal AET being more likely to have a normal MNBI value than patients with pH-positive NERD. These findings are consistent with previous findings from Frazzono, Savarino, etc. study and the study by Martinucci, de Bartoli, etc. Additionally, our results further confirmed previous studies that patients with ERD were more likely to have pH-positive ERD with an abnormal MNBI, which is reassuring for these characteristics to remain consistent. From these results, there is evidence that using MNBI enables us to better consistently diagnose and characterize GERD.



Disclosures:


Carter Edmunds, BS¹, Steven Clayton, MD, FACG², Chaewon Jeong, BS¹. D0200 - The Use of Mean Nocturnal Baseline Impedance for Aiding in Reflux Disease Diagnosis and Etiology Evaluation, ACG 2022 Annual Scientific Meeting Abstracts. Charlotte, NC: American College of Gastroenterology.