Gastric Emptying in Prematures of Isocaloric Feedings with Differing Osmolalities

Abstract

SummaryThe role of osmolar load in the regulation of gastric emptying time was studied in 10 healthy premature infants. Two isocaloric infant feedings of similar composition with mean osmolalities of 279 and 448 mOsm/kg were compared. Emptying was studied over 120 min by the double sampling marker dilution technique and by a single aspiration of the feediig at 30 min. Similar gastric emptying times were noted for both formulas with approximately half of the initial gastric contents remaining at 30 min. The secretory response to the two meals during the first 30 min after feeding was compared by measuring the secretions present in the stomach during that time. The mean secretory response to the feedings did not differ significantly and was less than 2.5 ml in both cases. In general, a biphasic pattern of gastric emptying with a rapid early emptying phase was noted with both feedings. This study, therefore, provides evidence that when isocaloric feedines with-similar combsition are used. osmolar load does not davva . " significant role 6 the regulation of gastric emptying in premature infants. This study also demonstrates that differences in osmolality do not significantly affect the secretory response to a meal in the stomach of the premature infant. SpeculationBy developing a better understanding of the factors which regulate gastric emptying time in infancy, a physiologic basis for dealing with clinical problems such as gastroesophageal reflux or inadequate gastric emptying by premature infants may be developed. These patients could benefit from infant formulas which are n"tritionally sound but empty more rapidly than formulas currently available. The present data indicate that osmolar load is not an important ?onsideration in the feediig of these patients. The role of other factors such as the specific constituents of a feeding or its caloric density remain to be determined.The manner in which an infant empties food from his stomach can have a significant effect on his nutrition and health. Infants with gastroesophageal (GE) reflux, severe enough to cause failure to thrive or recurrent pulmonary disease, have delayed gastric emptying compared with infants with mild GE reflux (1 1). Problems in nutritional support can occur when residual volumes from previous feedings limit the amount offered to a premature infant. A better understanding of the factors which control gastric emptying might improve the methods of dealing with these problems.Studies in adults and infants have demonstrated that the type of food offered can significantly effect emptying. Hunt and Stubbs (17) analyzed a number of studies in adults and concluded that the caloric density of a meal was the major determinant in the regulation of gastric emptying. Despite this conclusion, Cave11 (6) demonstrated in premature infants that an adapted cow's milk formula emptied significantly more slowly than human milk even though the feedings were isocaloric. Therefore, in infancy factors other than caloric density appear to play a role in regulating gastri...

Quantitative and Qualitative Study of Gastric Lipolysis in Premature Infants: Do MCT-Enriched Infant Formulas Improve Fat Digestion?

“…This assumption was adopted in some previous studies in which GE was calculated from the changes in total gastric volume with time. A halfemptying time of around 30 min was thus obtained in experiments with various milks (8,20). Using total gastric volume as the sole basis, the mean half-emptying time was found to be 86 around 25 min in our experiments.…”

Effects of Hypoxemia on Gastrointestinal Blood Flow and Gastric Emptying in the Newborn Piglet

“…Hyperosmolar feedings lead to greater stimulation of endogenous secretions, intraluminal water diffusion (35), and mucosal damage (36). However, osmolalities 5448 mOsmol/kg have not been associated with significant changes in gastric emptying (37), and 5 1000 mOsmol/kg have not been associated with intestinal hyperemia (38). Changes produced with a dextrose meal may not be reflective of the response to a milk feeding (17,39), since unanesthetized hypoxemic piglets given a milk feeding demonstrate a greater ability to maintain GI O2 consumption (40).…”

Gastric emptying in preterm infants.

“…The daily median (range) feed volume was 167 (150-235) ml/kg/day given at two, three, or four hourly intervals. The median (range) feed volume was 21 (13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29) mllkg. Feeds were administered by nasogastric tube over a median (range) period of 6 (3-12) minutes.…”