Abstract
PURPOSE: The KidZ Health Castle Formula (KHC-F) was developed to improve the positioning of multichannel intraluminal impedance-pH probes (MII-pH). We hypothesized that the updated formula KHC-Fv2 would performs better than the original formula. This study aimed to evaluate the reliability of KHC-Fv2. METHODS: A prospective cohort study was conducted to assess MII-pH probe positioning in patients aged 1 month to 18 years. Margins of error within 1 cm above or below the target position, as determined using KHC-Fv2 and compared with fluoroscopy, were accepted. RESULTS: Eighty-four children were included in the study. The mean difference between the KHC-Fv2 and target positions was +0.25 cm cranially. The KHC-Fv2 insertion length fell within the accepted difference of ±1 cm of the target position in 67.9% of the children. This percentage increased in infants under 1 year of age (79.5%) or shorter than 100 cm (74.0%) in height. CONCLUSION: KHC-Fv2 demonstrated strong agreement with correct positioning and significantly reduced the need for a second radiologic control after probe repositioning, particularly in infants or children shorter than 100 cm.