Changes in gastric emptying in early postnatal life.

Abstract

To study the pattern of gastric emptying in very premature infants and to determine whether there are changes with postnatal age and the ability to tolerate feedings. Sequential ultrasound measurements of the gastric antral cross-sectional area were obtained in 32 infants (mean gestational age, 26 +/- 1 weeks) before and after feeding for 2 hours. Studies were carried out after initiation of feedings, when full feedings were received, and at 32 weeks. Infants classified as feeding intolerant (n = 9) were also studied when feedings were restarted. Gastric emptying was assessed by the time taken for antral cross-sectional area to reach maximal value and to decrease to half the maximal increment (half-antral clearance). Delayed antral distention was observed at the time of the initial study in both feeding-tolerant (8 of 23) and feeding-intolerant (8 of 9) infants; however, there were significant differences in times for maximal antral distention (p < 0.002) and half-antral clearance (p < 0.006) between the feeding-tolerant and feeding-intolerant infants. By the time of full feedings, the feeding-intolerant infants showed immediate gastric emptying but still had a longer half-antral clearance time (p < 0.01). By 32 weeks, all infants had immediate antral distention and a more mature curvilinear pattern of gastric emptying. Knowledge of these different patterns of gastric emptying in very premature infants may lead to the development of more rational feeding strategies.