These findings suggest that baseline impedance is related to esophageal acid exposure and could be a marker of reflux-induced changes to the esophageal mucosa.

MII-pH recording is a promising procedure needing further validation and development to increase its additional benefit over conventional investigation techniques. The added value of the technique regards mainly clinical circumstances in which nonacid or weakly acid reflux may be relevant such as persisting symptoms during antireflux treatment with proton pump inhibitors and feeding-related reflux; and assessing specific discontinuous symptoms thought to be associated with gastroesophageal reflux; and research.

Interobserver agreement in combined pH-multichannel intraluminal impedance analysis in experts is moderate; only 42% of GER episodes were detected by the majority of observers. Detection of total GER numbers is more consistent. Considering these poor outcomes, AA seems favorable compared with manual analysis because of its reproducibility. However, the lower specificity rate suggests the need for refinement of AA before widespread use can be advocated.

No abstract

Background

Esophageal multichannel intraluminal impedance (MII) allows measurement of the conductivity of adjacent contents. During esophageal rest, raw impedance levels may represent mucosal integrity. We assessed the influence of proton pump inhibitors (PPIs) on presumed mucosal integrity by reanalyzing raw MII levels of 21 pH-MII tracings from infants with gastroesophageal reflux (GER) disease before and after esomeprazole treatment. Median (interquartile range) esophageal MII increased during treatment, 938 (652-1304) versus 1885 (1360-2183) Ohm, P < 0.0001. Patients with lower MII levels demonstrated a larger increase on therapy: Spearman r2 = 0.28, P = 0.014. No correlation with standard GER parameters was observed. In conclusion, PPI therapy increases MII levels in infants with symptomatic GER disease.

No abstract

"Symptomatic gastroesophageal reflux disease" implies disease causation for distressing infant symptoms. In infants with symptoms attributed to GER, LLP produced a significant reduction in total GER, but did not result in a significant improvement in symptoms other than vomiting; however, automated analysis appeared to identify infants with GER-associated crying symptoms who responded to positioning therapy. This is an important new insight for future research.