Variability of the 13C-acetate breath test for gastric emptying of liquids in healthy children.
OBJECTIVE
Scintigraphy is considered as the "gold standard" for measuring gastric emptying (GE). The C-acetate breath test (C-ABT) offers an attractive alternative to measure GE of liquids as it is nonradioactive. The aim of this study was to assess the variability of the C-ABT for GE of liquids in healthy children using nondispersive infrared spectrometry (NDIRS).


METHODS
The C-ABT was repeated at least 2 times in 21 healthy children (6 girls and 15 boys), aged between 6.2 and 16.4 years, 2 to 7 days apart. After an overnight fast, a standardized milk drink, labeled with 50 or 100 mg C-acetate according to weight, was administered. Breath samples were taken before feeding, at 5-minute intervals for the first 40 minutes and at 10-minute intervals for the following 140 minutes after feeding. Breath samples were analyzed using NDIRS, and C recovery was used to calculate values for gastric half-emptying time (t1/2), time of peak C exhalation, or gastric lag phase (tlag) and gastric emptying coefficient (GEC). Intraindividual variabilities of the parameters t1/2, tlag, and GEC were expressed as coefficient of intrasubject variation (CV).


RESULTS
The median CV of t1/2 was 8.3% (CV range, 1.6%-16.2%; t1/2 interindividual range, 65-112 minutes; and t1/2 intraindividual range, 4-33 minutes). The median CV of tlag was 16.6% (CV range, 2.0%-26.6%; tlag interindividual range, 31-76 minutes; and tlag intraindividual range, 1-35 minutes). The median CV of GEC was 4.3% (CV range, 0.8%-15.7%; GEC interindividual range, 3.81-4.89; GEC intraindividual range, 0.08-1.31). The CVs of t1/2, tlag, and GEC were independent of age, sex, weight, height, and measured values of t1/2, tlag, and GEC.


CONCLUSIONS
The C-ABT using NDIRS is an easy, noninvasive, and nonradioactive procedure with a large intraindividual variation for measuring GE of liquids in healthy children, but comparable to the variation reported with other techniques.
Hauser
B
B
Department of Paediatrics, Academisch Ziekenhuis, Vrije Universiteit Brussels, Brussels, Belgium. bruno.hauser@az.vub.ac.be
De Schepper
J
J
Caveliers
V
V
Salvatore
S
S
Salvatoni
A
A
Vandenplas
Y
Y
D000293:Adolescent; D001835:Body Weight / Q000502:physiology; D001944:Breath Tests / Q000379:methods*; D002247:Carbon Isotopes / Q000032:analysis; D002648:Child; D004305:Dose-Response Relationship, Drug; D005260:Female; D005746:Gastric Emptying; D006801:Humans; D008297:Male; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013055:Spectrophotometry, Infrared / Q000379:methods* / Q000592:standards*
D002247:Carbon Isotopes