Neonatal Fellow University of Connecticut School of Medicine Newington, Connecticut, United States
Background: Gastroesophageal reflux disease is common in the NICU. There are published guidelines outlining a stepwise approach to manage GERD, starting with non-pharmacologic strategies (feed modifications such as eliminating cow’s milk protein, thickening feeds, increasing feeding time, decreasing feed volume, etc.), followed by medications. Breast milk or formulae are subjected to such modifications, but the physicochemical changes (pH, viscosity, etc) that occur in the stomach after feeds with modifications are not well described Objective: Determine if there are significant differences in intensity and duration of gastric pH change after feeds with maternal breast milk and formula in preterm infants on gavage feeds Design/Methods: IRB-approved prospective pilot case-control study was done in two tertiary care NICUs. Stable preterm infants at 32 0/7-37 0/7 weeks PMA receiving bolus gavage feeds of maternal breast milk or preterm formula were included. Unstable infants, infants with gastrointestinal problems, and those on continuous feeds were excluded. A sample size of 30 subjects was estimated to provide an adequately powered study. 0.5 mL of gastric contents were collected from the feeding tube pre-, post-, and 1 hour following a gavage feed. pH was measured using Apera Instruments (Switzerland) LabSen 241-3SP probe and PH850 pH meter. Collection and pH measurement were repeated over 5 subsequent days. The baseline pH of the feed pre-gavage was also measured. After completing recruitment, we will report on the demographics of the two groups. Comparisons will be made of the time course of gastric pH changes from the beginning of one feed to the start of the next using paired t-tests and repeated measures ANOVA statistics. Change patterns in maternal breast milk feeds will be compared to preterm formula feeds using univariate analyses (unpaired t-tests or chi-square test), and confounding variables will be adjusted using propensity score matching of the subjects. All the statistical tests will be two-sided, and P-values < 5% will be considered statistically significant.
