Is the correction factor used in the breath test assessment of gastric emptying appropriate for use in infants?
OBJECTIVE
The gastric emptying breath test (GEBT) is now routinely used in many centers. Validation studies in adults have shown that although there is a linear correlation between the GEBT and scintigraphy, the GEBT overestimates gastric half emptying time (GEt1/2) by a constant of approximately 60 minutes because of postgastric processing. It is therefore conventional to apply a "correction factor" to the GEBT result. Because = no similar validation studies have been performed in infants, the aim of this study was to directly characterize the postgastric processing of 13C octanoic acid in infants to assess the suitability of the standard correction factor for use in infants.


METHODS
The pattern of breath 13CO2 excretion after separate infusion of 13C octanoic acid into either the stomach or the duodenum was measured in 13 healthy preterm infants (6 male, 7 female). The raw 13CO2 half excretion time after intragastric (GEt1/2 raw) and intraduodenal (DEt1/2 raw) administration of C octanoic acid was calculated, and the difference between GEt1/2 raw and DEt1/2 raw (i.e., GEt1/2 raw - DEt1/2 raw) was directly compared with GEt1/2 corrected, derived by applying the standard correction factor to GEt1/2 raw.


RESULTS
Values for GEt1/2 raw - DEt1/2 raw correlated significantly with GEt1/2 corrected.


CONCLUSIONS
Our results show that the standard correction factor is appropriate for performing the GEBT in preterm infants.
Omari
Taher I
TI
Centre for Paediatric and Adolescent Gastroenterology, Women's and Children's Hospital and Department of Paediatrics, University of Adelaide, Adelaide, South Australia. taher.omari@adelaide.edu.au
Symonds
Erin
E
Davidson
Geoffrey P
GP
Butler
Ross N
RN
D019540:Area Under Curve; D001944:Breath Tests / Q000379:methods*; D002210:Caprylates; D002247:Carbon Isotopes; D005069:Evaluation Studies as Topic; D005260:Female; D005746:Gastric Emptying / Q000502:physiology*; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature / Q000502:physiology*; D008297:Male; D008433:Mathematics; D012016:Reference Values; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D002210:Caprylates; D002247:Carbon Isotopes