Background: The 13C-octanoic acid breath test has been used to measure gastric emptying in preterm infants, but the reproducibility of the test has not been evaluated in this population.
Methods: Fifty-six paired breath test analyses were performed on 28 healthy preterm infants 1 to 5 days apart using the same food type, volume, and energy content for each paired sample. Breath samples were taken before the feeding, at 5-minute intervals after feeding for 30 minutes, then each 15 minutes for 4 hours. Samples were analyzed using an isotope-ratio mass spectrometer, and 3C recovery was used to calculate values for gastric-emptying coefficient and gastric half-emptying time.
Results: There was no significant difference between test results on different days in the paired samples studied. gastric-emptying coefficients for the first and subsequent samples were 2.6+/-0.1 (mean+/-SEM) and 2.7+/-0.1, respectively, and half-emptying times were 44.5+/-3.7 minutes and 41.4+/-3.2 minutes.
Conclusion: The 13C-octanoic acid breath test is a reliable, noninvasive, and reproducible measure of gastric emptying in preterm infants that should have wide application for use in this population.