[Impedance-pH analysis in gastroesophageal reflux monitoring]

Abstract

Gastroesophageal reflux is defined as regurgitation of the stomach contents into the esophagus due to transient or persistent failure of the lower esophageal sphincter. The measurement of impedance is a new technique used to diagnose gastroesophageal reflux. This technique is devoid of restrictions connected with classical esophageal pH-metry. Multichannel intraluminal impedance depends on changes in resistance to alternating current between two metal ring electrodes (impedance measuring segment) generated by the presence of bolus within that segment. The impedance measuring segments are located at 3, 5, 7, 9 cm (distal esophagus) and at 15 and 17 cm (proximal esophagus) over the proximal margin of the lower esophageal sphincter. The technique allows for classification of gastroesophageal reflux incidents as acid, weakly acidic and non-acid, assessment of reflux contents as liquid, gas or gas-liquid and the height of reflux regurgitation into the esophagus. The usefulness of pH-impedance analysis is still difficult due to the lack of normal values in children.