13C-octanoic acid breath test (13C-OABT) is a method that has recently been used for monitoring of gastric emptying. The study was performed to investigate of gastric emptying in premature infants. Methods: The 13C-OABT was performed in 23 stable preterm newborns born between the 31st and 37th weeks of gestation (mean 34.4, SD 1.5). Birth weight was 1400-2680 (mean 2094, SD 329) grams. 13C-primed breast milk (the test meal) was prepared by adding 13C-octanoic acid to pasteurized breast milk so that the resulting concentration was 1 microlitre 13C-octanoic acid per 1ml of milk. The representation of 13C and 12C in the expired air samples was examined by mass spectrometry. Results were expressed as delta over baseline and related to the international standard of Pee Dee Belemnite Limestone. The mathematical method of assessing T1/2E consisted of modeling the process of elimination by using the incomplete gamma function. The curves were determined by the half-life of elimination of 13CO2 (T1/2E) and characterized by the shape of the elimination curve. Results: A total of 62 13C-OABT were analyzed in 23 premature newborns. The mean and standard deviation and the median of T1/2GE calculated from all three tests were 52.7 (SD 28.6) and 46.9 min respectively. Intraindividual coefficient of variation was 0.23-33.56% (mean 10.6 %). Conclusions: 13C-OABT is a method used for the examination of gastric emptying which can be applied also in preterm neonates.

        Key words: 13C-octanoic acid breath test; premature infants; gastric emptying