title: Validity of 13C octanoic acid breath test for measurement of solid meal gastric emptying time in children.
abstract: OBJECTIVE
  It is important to establish a physiologic range of gastric emptying (GE) in children. Gastric emptying time measured with (99)Tc-labeled solid meal (GE(Tc)) is the gold standard. Large-scale studies with GE(Tc) are ideal but not feasible because of radiation exposure. The (13)C-labeled octanoic acid breath test (GE(13C)) does not involve radiation and is suitable for large studies. The aim of this study was to validate GE(13C) with GE(Tc) and to explore whether GE(13C) could be used to establish a physiologic range of GE in children.
  
  
  METHODS
  Twenty-five healthy children underwent simultaneous GE(Tc) and GE(13C) using a standardized solid test meal. The time taken for the stomach to empty half its content (T(1/2)(13C)) and solid lag phase (lag(13C)) for GE(13C) were computed from the fractional excretion of (13)C in expired air. T(1/2)(13C) and lag(13C) were compared with corresponding values obtained by GE(Tc).
  
  
  RESULTS
  Correlation coefficient between T(1/2)(13C) and T(1/2)(Tc) was 0.69 (P < .01; r = 0.92 if 3 outliers were omitted). Correlation coefficient between lag(13C) and lag(Tc) was 0.39 (P < .05). There was good agreement between the methods by the Bland Altman method.
  
  
  CONCLUSIONS
  There is good agreement between GE(13C) and GE(Tc). GE(13C) can be safely used to establish the reference range of GE in healthy children.
authors.affiliation: Department of Paediatric Surgery, Leicester Royal Infirmary, LE1 5WW Leicester, UK.
authors.forename: B
authors.initials: B
authors.lastname: Eradi
authors.forename: J
authors.initials: J
authors.lastname: Wright
authors.forename: Nicola J
authors.initials: NJ
authors.lastname: Gibbons
authors.forename: P Elaine
authors.initials: PE
authors.lastname: Blackshaw
authors.forename: Alan C
authors.initials: AC
authors.lastname: Perkins
authors.forename: Jennifer
authors.initials: J
authors.lastname: Wakefield
authors.forename: J
authors.initials: J
authors.lastname: Sithole
authors.forename: Shailinder Jit
authors.initials: SJ
authors.lastname: Singh
mesh_terms: D001944:Breath Tests; D002210:Caprylates; D002250:Carbon Radioisotopes; D002648:Child; D002675:Child, Preschool; D005746:Gastric Emptying / Q000502:physiology*; D006801:Humans; D019275:Radiopharmaceuticals; D013667:Technetium; D013997:Time Factors
chemical_list: D002210:Caprylates; D002250:Carbon Radioisotopes; D019275:Radiopharmaceuticals; D013667:Technetium; C031492:octanoic acid