Comparison of the gastric emptying results among the 13C-octanoic acid breath tests, scintigraphy, and acetaminophen method

Abstract

The 13C-octanoic acid breath test has been thought to be one of the most important methods in gastric emptying, because it is non-invasive and needs no special device. In this study, we evaluated the gastric emptying results between the 13C-octanoic acid breath tests, scintigraphy, and acetaminophen method. Ten patients with non-ulcer dyspepsia and 4 healthy volunteers were studied. For the test meal, we used scrambled egg, white bread, and 150 ml water and into the scrambled egg, 100 mg of 13C-octanoic acid, 37 MBq 99mTc-DTPA, and 20 mg/kg body weight of acetaminophen were mixed. After eating, breath samples and scanning scintigraphic information was obtained up to 8 and 2 hours, respectively. Blood sample was obtained 45 minutes after eating and the concentration of serum acetaminophen were measured. Previously, a positive correlation between the half emptying time (t1/2) determined by breath test and scintigraphy, was reported by Ghoos et al.(1993) (y=1.12x+66.1, R2=0.79, p<0.0001) and in this study a positive correlation was found (y =0.76x +113, R2=0.29, p=0.047). There was a negative correlation between the t, 12 determined by scintigraphy and the concentration of serum acetaminophen (y=-0.12x+15.9, R2=0.40, p=0.013). In case of that 13CO2 excretion of breath test was remained, even 8 hours after eating, t1/2 and lag phase determined by breath test were more delayed than actual state. In case of that 13CO2 excretion curve in early phase was drawn like sigmoid curve, t1/2 determined by breath test were more delayed than actual state. In case of that 13CO2 excretion curve had two peak-points, there was no problem. In conclusion the 13C octanoic acid breath test is a promising and reliable method for measuring gastric emptying.