title: Nondispersive infrared spectrometry for 13CO2/12CO2-measurements: a clinically feasible analyzer for stable isotope breath tests in gastroenterology.
abstract: BACKGROUND
  13C-urea breath tests have become clinical routine for the diagnosis of Helicobacter pylori infection and other isotope breath tests have been invented e.g. for gastric emptying or quantitative liver function testing. Recently, isotope-selective nondispersive infrared spectrometers (NDIRS) have been developed for the analysis of the 13CO2/12CO2-enrichment in breath. In this study, we prospectively tested the validity of a newly developed NDIRS in comparison to isotope ratio mass spectrometry (IRMS).
  
  
  METHODS
  142 patients with dyspeptic symptoms were tested for Helicobacter pylori infection using the 13C-urea breath test. The isotope ratio analysis of the breath samples was performed in duplicate both using IRMS and NDIRS.
  
  
  RESULTS
  The results of the baseline-corrected 13CO2-exhalation values between IRMS and NDIRS were in excellent agreement. The mean difference between both methods was 0.28 +/- 1.93 delta/1000. Evaluating the qualitative urea breath test results in reference to IRMS as the reference the NDIRS had a sensitivity of 97.8% and a specificity of 98.9%.
  
  
  CONCLUSIONS
  The isotope-selective nondispersive infrared spectroscopy is going to become a reliable, but low-cost and easy-to-operate alternative to expensive isotope ratio mass spectrometry in the analysis of 13C-breath tests.
authors.affiliation: Medical Department II, Johann Wolfgang Goethe University Frankfurt/Main.
authors.forename: B
authors.initials: B
authors.lastname: Braden
authors.forename: W F
authors.initials: WF
authors.lastname: Caspary
authors.forename: B
authors.initials: B
authors.lastname: Lembcke
mesh_terms: D000328:Adult; D001944:Breath Tests / Q000379:methods*; D002245:Carbon Dioxide / Q000032:analysis; D002247:Carbon Isotopes; D002250:Carbon Radioisotopes; D005260:Female; D016481:Helicobacter Infections / Q000175:diagnosis*; D016480:Helicobacter pylori; D006801:Humans; D016014:Linear Models; D008297:Male; D013058:Mass Spectrometry / Q000379:methods; D008875:Middle Aged; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D013055:Spectrophotometry, Infrared / Q000379:methods; D014508:Urea
chemical_list: D002247:Carbon Isotopes; D002250:Carbon Radioisotopes; D002245:Carbon Dioxide; D014508:Urea