Wagner-Nelson method for analysing the atypical double-peaked [13CO2] excretion curve in the [13C]-octanoate gastric emptying breath test in humans.
1. In the [(13)C]-octanoic acid breath test, the time versus pulmonary [(13)CO(2)] excretion rate curve is analysed using mathematical curve-fitting techniques to calculate gastric emptying parameters. Thus, the goodness-of-fit highly influences the accuracy of the breath test. However, a double-peaked [(13)CO(2)] excretion curve, which occasionally develops owing to the presence of an interval of quiescent gastric emptying (the plateau phase), is likely to be fitted poorly. 2. In pharmacokinetics, the Wagner-Nelson method has been used to describe precisely the absorption kinetics of orally administered drugs and its reliability is independent of the nature of gastric emptying. A recent study has shown the potential of the Wagner-Nelson method to generate a realistic gastric emptying flow curve from [(13)CO(2)] excretion data. In the present report, we have demonstrated that the Wagner-Nelson method can visualize the plateau emptying phase responsible for the cases of double peaks. 3. Wagner-Nelson analysis applied to the breath test described precisely the characteristic emptying pattern of the two emptying phases being interrupted by the plateau phase. Conventional analysis for the breath test failed to detect the plateau phase. 4. The Wagner-Nelson method is a useful tool for analysing atypical double-peaking [(13)CO(2)] excretion curves.
Sanaka
Masaki
M
Department of Internal Medicine, School of Medicine, Teikyo University, Tokyo, Japan.
Yamamoto
Takatsugu
T
Tsutsumi
Hiroko
H
Abe
Koichiro
K
Kuyama
Yasushi
Y
D000328:Adult; D001944:Breath Tests / Q000379:methods*; D002210:Caprylates / Q000008:administration & dosage / Q000493:pharmacokinetics*; D002245:Carbon Dioxide / Q000032:analysis* / Q000378:metabolism; D002247:Carbon Isotopes; D005746:Gastric Emptying / Q000502:physiology*; D006801:Humans; D007408:Intestinal Absorption; D008875:Middle Aged; D008954:Models, Biological
D002210:Caprylates; D002247:Carbon Isotopes; D002245:Carbon Dioxide; C031492:octanoic acid