Is the 13C-acetate breath test a valid procedure to analyse gastric emptying in children?

Scintigraphy is regarded as the "gold standard" procedure in measuring gastric emptying (GE) rates. 13C-acetate breath test (ABT), which already has been validated in adults, is a noninvasive and nonradioactive alternative method. The aim of the current study was to validate ABT against technetium Tc 99m scintigraphy in children affected by delayed GE.

Sixty children were recruited and divided into 2 groups: group A, 30 healthy controls; group B, 30 patients with gastroesophageal reflux, and scintigraphy-documented DGE (15 neurologically impaired). After an overnight fast, all of them underwent ABT using 25 to 150 mg 13C-acetate. Breath samples were obtained at baseline and then every 10 minutes for 2 hours. The 13CO2 to 12CO2 ratio in breath samples was analysed by isotope ratio mass spectrometry. Data are expressed as follows: time of peak 13C exhalation (tP13CO2b) and half emptying time in ABT (t(1/2b)), and scintigraphy half emptying time (t(1/2s)).

In controls tP13CO2b was 37 +/- 13 minutes and t(1/2b) 74 +/- 12 minutes. In patients tP13CO2b and t(1/2b) were, respectively, 65 +/- 26 minutes and 104 +/- 18 minutes t(1/2s) was 91 +/- 21 minutes. In group B tP13CO2b and t(1/2b) were delayed significantly compared with controls, respectively, P < .03 and P < .01. In group B significant correlation between t(1/2s) and t(1/2b) was noted (r1 = 0.97). A close correlation was also observed between t(1/2s) and tP13CO2b (r2 = 0.95).

The 13C ABT is an easy, reliable, and less expensive procedure for measuring GE, and its results closely correlate with those of scintigraphy in a paediatric population.