Abstract
INTRODUCTION: . When the acid exposure time is inconclusive (4-6%), complementary findings such as the mean nocturnal basal impedance could collaborate in the diagnosis of the presence or absence of gastroesophageal reflux disease. In this study we consider the usefulness of mean nocturnal basal impedance in clinical practice for the diagnosis of gastroesophageal reflux disease. OBJECTIVES: . Our objectives were to compare mean nocturnal basal impedance in patients with suspected non-erosive reflux disease versus healthy controls and in patients with different levels of acid exposure time, to determine the association between mean nocturnal basal impedance and classical impedance-pH measurements, and explore the added diagnostic value of mean nocturnal basal impedance in the inconclusive area of acid exposure time. PATIENTS AND METHODS: . We conducted a prospective observational study in a tertiary care center in the Autonomous City of Buenos Aires, Argentina, between January 2017 and December 2018. Consecutive patients older than 18 years referred for typical symptoms of gastroesophageal reflux disease without proton pump inhibitors response were included. Patients older than 18 years of age referred consecutively for extraesophageal symptoms, in whom the presence of gastroesophageal reflux disease was ruled out, were considered the control group. All patients underwent upper digestive video endoscopy, high-resolution esophageal manometry and 24-hour ambulatory pH-impedance measurement, after discontinuing proton pump inhibitors for 4 weeks. RESULTS: . 59 patients with suspected non-erosive reflux disease refractory to proton pump inhibitors treatment and 17 controls were included. In patients with suspected non-erosive reflux disease, a significant difference was found in mean nocturnal basal impedance between the 3 acid exposure time groups analyzed. There was a moderate negative correlation between mean nocturnal basal impedance and acid exposure time, number of reflux episodes and hiatal hernia size. Of the 7 patients with inconclusive acid exposure time, 5 patients (71.4%) had a mean nocturnal basal impedance < 2292 Ohms and responded to a double dose of proton pump inhibitors. The remaining two patients with moderate negative correlation between > 2292 Ohms did not respond to double-dose proton pump inhibitors. CONCLUSION: . Our study reflects a real-world approach to the evaluation and management of gastroesophageal reflux disease. Our findings support the use of mean nocturnal basal impedance in clinical practice as a complementary element to add confidence in the evaluation of the presence of gastroesophageal reflux disease, especially when acid exposure time is inconclusive.