DEMONSTRATION OF All ADEQUATE BARRIER TO GASTROESOPHAGEAL REFLUX IN THE NEWBORN AND PRETERM INFANT

Abstract

Previous investigators have stated that newborn and preterm infants have an incompetent lower esophageal sphincter (LES) and are therefore susceptible to gastroesophageal reflux (GER) and aspiration pneumonia. We tested this hypothesis by comparing 5 “healthy” preterm and 10 fullterm infants to 10 infants under 1 yr. age with GER. GER was defined by free reflux of barium on barium swallow roentgcnograms, or the persistence of acidic fluid (pH 4) in the lower esophagus following gastric infusion on 0.1N HCL in a dose of 173 cc/m2 body surface area. LES pressure gradients were measured by withdrawing a single lumen side opening catheter perfused with H2O at 1.3 cc/min. from the stomach into the esophagus. Pressure gradients across the LES were as follows: All normal preterm and fullterm neonates exhibited LES pressure gradients strikingly higher than infants with GER (p<0.001). Our data suggest that infants with LES pressure gradients of less than 25 mmHg may be at risk for GER, and that healthy preterm and fullterm neonates have a competent lower esophageal sphincter.