Evaluation of the 13C-aminopyrine breath test using nondispersive infrared spectrometry

Objective : the aim of the study was to assess the value of the 13C Aminopyrine Breath Test (ABT) when performed using the NonDispersive InfraRed Spectrometry (NDIRS), which is a simple and cheap alternative to the mass spectrometry. Methods : The results obtained by using the NDIRS method for performing the ABT were compared to the results obtained by a reference method, the 14C Aminopyrine Breath Test. For this purpose, in 32 patients admitted for various liver problems, an ABT was performed by using the 2 methods simultaneously. The repeatability of the results obtained at 120 minutes by the NIDRS method as compared to the 14C test was; assessed by the method of Bland and Altman. Results : The mean of difference between the results obtained by both methods at 120 minutes was 0.06 ± 0.46. The coefficient of repeatability between the two tests was 0.92 for a confidence interval of 95%. A good correlation (r = 0.93) was found between all individual results obtained in breath samples at different times of collection (30, 60, 90, 120 minutes), and between the results obtained at 120 minutes for both 13C and 14C tests (r = 0.94). Conclusion: The 13C ABT performed using NDIRS is a valid alternative to the 14C technique in routine clinical practice.