Correlation of gastric emptying at one and two hours following formula feeding

The acquisition of gastric emptying (GE) data by scintigraphy has become an important component of the evaluation of the pediatric patient for gastroesophageal reflux (GER). Delay of GE can contribute to ongoing gastric distension and hence increase propensity to reflux. Generally, only 1 h GE is determined during scintigraphy. Infants with GER have variable patterns of symptoms: some have spitting, vomiting, choking, and/or apparent life-threatening events in the immediate post-prandial period only, whereas in others symptoms persist until the time of next feeding. It is not clear whether differential rates of GE contribute towards such disparity of symptoms. We performed this prospective study to determine the correlation between GE at 1 h or 2 h, respectively, and for 2 h following a feeding in 27 infants under one year of age, who were referred for evaluation of GER. Continuous scintigraphy was performed for 2 h following a formula feeding. Gastric emptying at 1 h was calculated as percent of original dose emptied by 60 min; GE at 2 h was calculated as percent of isotope remaining in the stomach at 60 min which was emptied by 120 min. The median GE between 0 to 60 min was 36% (95% CI 26.0-42.0) and median GE of the residual formula between 60 to 120 min was 45% (95% CI 34.3-51.3). The correlation coefficient of GE, at 1 h with total GE over 2 h was 0.75 and of GE during the 2nd h with total GE over 2 h was 0.76. We conclude that routine determination of GE for 2 h continuously does not appear to offer clinically significant additional information.