Outcomes of endoscopy and novel pH-impedance parameters in children: is there a correlation?

Objectives: Discordance exists between outcomes of endoscopy, multichannel intraluminal impedance monitoring (pH-MII), MII baselines, and gastroesophageal reflux symptoms. The aim of the present study was to determine the association between endoscopy, pH-MII and MII baselines, in children with gastroesophageal reflux symptoms.

Methods: Endoscopies were graded for reflux esophagitis (RE). Biopsies of the distal esophagus were assessed for signs suggestive of esophagitis. Reflux index (RI), symptom association probability (SAP), number of reflux episodes, and mean baseline values were calculated. pH-MII was considered positive in children when RI was ≥ 3% and/or SAP was ≥ 95% and for infants when RI was ≥ 10% and/or SAP was ≥ 95%. Baselines were manually calculated and compared with an automated analysis. For MII baselines, patients were divided in 3 groups: normal endoscopy and negative overall pH-MII; normal endoscopy and an overall positive pH-MII; and RE.

Results: A total of 26 children and 14 infants were included, median age: 26.5 months (2 months-16.2 years). Thirteen (32.5%) had RE. A significant negative association was found for RI and MII baselines (P = 0.009) and between SAP and RE (P = 0.039, odds ratio 1.018). MII baseline values were predictive for neither conventional pH-MII parameters nor RE. Manual analysis and automated calculation of MII baselines showed a perfect correlation. Distal MII baselines were significantly lower in children with a positive overall pH-MII outcome compared with the proximal esophagus (P = 0.049). No significant changes were found in baselines among the different groups 1 to 3.

Conclusions: Acid-related parameters are significantly related to MII baselines. A perfect correlation between manual- and automated analysis of MII baselines was found. Large prospective studies are needed to confirm the exact role of endoscopy and MII baselines.