Effects of thickened feeding on gastroesophageal reflux in infants: a placebo-controlled crossover study using intraluminal impedance.

OBJECTIVE Thickening of formula feedings is part of the therapeutic approach for gastroesophageal reflux (GER) in infants. However, its mechanism of action, especially regarding the occurrence of nonacid (pH >4) GER, has not yet been clearly described. The aim of this randomized, placebo-controlled crossover study was to examine the influence of formula thickened with carob (St. John's bread) bean gum on acid and nonacid GER. METHODS Infants with recurrent regurgitation and without other symptoms were fed alternately (A-B-A-B-A-B) with thickened (A) and nonthickened (B) but otherwise identical formula. Documentation of GER episodes during the study was performed by simultaneous intraesophageal impedance measurement (intraluminal electrical impedance; IMP) and pH monitoring. The IMP technique is able to detect bolus movements inside a luminal organ. The use of multiple measuring segments on a single catheter allowed the analysis of direction, height, and duration of the bolus transport. Continuous videorecording and visual surveillance of regurgitation frequency and amount resulted in a severity score. RESULTS Fourteen infants (42 +/- 32 days old) were examined during 6 feeding intervals each for a total measuring time of 342 hours. A total of 1183 GER episodes and 83 episodes of regurgitation were registered. Regurgitation frequency (15 vs 68 episodes) and amount (severity score 0.6 vs 1.8) were significantly lower after feedings with thickened formula. The difference regarding the occurrence of GER documented by IMP was also pronounced (536 vs 647 episodes). Although not statistically significant, maximal height reached by the refluxate in the esophagus was decreased after thickened feedings. Mean GER duration and the frequency of acid (pH <4) GER were not altered. CONCLUSIONS Thickened feeding has a significant effect on the reduction of regurgitation frequency and amount in otherwise healthy infants. This effect is caused by a reduction in the number of nonacid (pH >4) GER episodes, but also because of a decrease of mean reflux height reached in the esophagus. However, the occurrence of acid GER is not reduced. The combination of IMP and pH monitoring allows the complete registration and description of these GER episodes. Thickening of formula feedings with carob bean gum is an efficient therapy for uncomplicated GER in infants.