Acid Gastroesophageal Reflux in Symptomatic Infants Is Primarily a Function of Classic 2‐phase and pH‐only Acid Reflux Event Types

Abstract

BACKGROUND: Combined esophageal pH monitoring (EPM) and multichannel intraluminal impedance (MII) reveal 4 unique acid gastroesophageal reflux (AGER) types in infants: classic 2-phase, single-phase, pH-only events (POEs), and re-reflux episodes. The extent to which different AGER event types contribute to AGER frequency, acid reflux exposure time (ARET), and the number of episodes lasting 5 minutes or longer, has never been reported. In this study, EPM/MII was used to assess AGER in symptomatic infants on the basis of these 4 AGER types. MATERIALS AND METHODS: EPM/MII tracings from 12 symptomatic infants (<12 months old) were examined. Mean frequencies and durations of each AGER type, percentages of total ARET due to each AGER type, and percentages of different AGER types lasting 5 minutes or longer, were measured. RESULTS: Of 926 total AGER events, 23.1%, 6.3%, 69.2%, and 1.5% were classic 2-phase, single-phase, POEs, and re-reflux episodes, respectively. In 20.2 hours of combined ARET, 52.3%, 2.3%, 42.4%, and 3.0% occurred during classic 2-phase, single-phase, POEs, and re-reflux episodes, respectively. Classic 2-phase and POE events were both more frequent than single-phase (P = 0.002 and P < 0.0001) and re-reflux (P = 0.002 and P < 0.0001) episodes, respectively. Increasing numbers of AGER episodes were strongly correlated with POEs (P = 0.0001). Of the 35 total AGER episodes that lasted 5 minutes or longer, 94% were classic 2-phase episodes or POEs (57% and 37%, respectively). CONCLUSIONS: In symptomatic infants, total AGER episodes, total ARET, and AGER episodes lasting 5 minutes or longer are largely a function of classic 2-phase and pH-only AGER types.