Reflux episodes detected by impedance in patients on and off esomeprazole: a randomised double-blinded placebo-controlled crossover study
Dr F. J. Moawad, Gastroenterology Service, Department of Medicine, Walter Reed National Military Medical Center, 8901 Wisconsin Ave., Bethesda, MD 20889, USA.
Combined with 24-h pH monitoring, the use of impedance is the most sensitive method available for detecting oesophageal reflux. Normal values for impedance have been previously established in healthy controls studied on and off proton pump inhibitors (PPI).
To determine the effects of PPIs on the total number of reflux episodes in the distal oesophagus measured by impedance in patients with and without gastro-oesophageal reflux disease (GERD).
In this prospective randomised double-blinded placebo controlled crossover study, all patients underwent two 24-h pH with impedance studies at least 2 weeks apart. Based on a randomisation scheme, patients received either 40 mg of esomeprazole twice daily for 1 week or identical capsule placebo for 1 week, then all patients were crossed over to the other treatment arm. GERD was defined by the validated Johnson–DeMeester score. Reflux by impedance was defined as a 50% decrease from baseline in retrograde movement of liquid between two impedance sites.
Sixty-three patients were enrolled and 41 patients completed the study [mean age 52 ± 12 years, 42% (17/41) men, 56% (23/41) Caucasian and 34% (14/41) African American]. Overall, there was no significant decrease in the total number of distal impedance episodes with esomeprazole compared with placebo (mean change 6.1 ± 22, P = 0.100). When analysed separately by GERD status, among GERD-positive patients, there was a significant decrease in distal impedance episodes while on esomeprazole compared with placebo (mean change −16 ± 22, P = 0.023), but not in GERD-negative patients (mean change −0.35 ± 20, P = 0.872).
Esomeprazole decreases significantly the number of reflux episodes detected by impedance, but only in patients with GERD.