Submitted to: Journal of Pediatrics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/12/2006
Publication Date: 10/20/2006
Citation: Ramirez, A., Wong, W.W., Shulman, R.J. 2006. Factors regulating gastric emptying in preterm infants. Journal of Pediatrics. 149(4):475-479. Interpretive Summary: Preterm infants have a lot of difficulty tolerating feedings but it is not clear what factors contribute to this. To understand better how the stomach works in preterm infants and whether this relates to feeding intolerance, preterm infants underwent testing with different variations of feedings to test whether the concentration, volume, or the amount of nutrients affect how the stomach empties. Unlike adults, none of these factors in isolation affected stomach emptying. However, when changes in concentration and volume were combined, stomach emptying was affected. This may explain why preterm infants do better with half strength feedings given in larger volumes than more concentrated feedings.
Technical Abstract: OBJECTIVES: To determine whether osmolality, volume, or energy density affects gastric emptying rate (GE); whether simultaneously decreasing osmolality and increasing volume accelerates GE; and whether GE is related to any clinical and/or demographic characteristics. STUDY DESIGN: GE was measured using the (13)C-octanoic acid breath test in 17 infants of 25 to 30 weeks gestation in a tertiary care children's hospital. In study 1, the independent effects of osmolality, volume, and nutrient density were evaluated in 10 infants. In study 2, the combined effects of decreasing osmolality and increasing volume were evaluated in 7 infants. Results from all infants were used to investigate the relationships between clinical and demographic characteristics and GE. The statistical analysis comprised analysis of covariance, the (paired) Student t-test, the 1-sample Wilcoxon test, and regression analysis. RESULTS: Mean (+/- standard deviation) age was 27.7 +/- 14.6 days in study 1 and 34.1 +/- 14.0 days in study 2. Altering osmolality, volume, or energy density did not change GE, but simultaneously decreasing osmolality and increasing feeding volume accelerated GE by 18% versus standard feeding. GE correlated with gestational age at birth. CONCLUSIONS: Unlike in adults, in preterm infants osmolality, volume, or energy density individually do not affect GE. Reducing osmolality and increasing feeding volume increases GE. GE is related to gestational age at birth even at age 1 month.