Role of the Multichannel Intraluminal Impedance Technique in Infants and Children

Abstract

Recently, multichannel intraluminal impedance (MII) was added to the repertoire of tests available to study esophageal (patho)physiology in children. MII has since been used in 2 major areas. First, it has been used as a diagnostic test for gastroesophageal reflux disease (GERD). The main advantage over traditional pH monitoring is its ability to detect both acid and nonacid gastroesophageal reflux (GER) and to discern between liquid and gas GER.Although feasible with multiple pH sensors, the MII technique routinely detects the proximal extent of a GER episode. When a pH sensor is added to the MII-catheter, important information about the acidity of a GER event can be gathered.The second area in which the role of MII has been investigated is that of esophageal function testing. Manometry classically reveals information about esophageal pressure patterns and sphincter function, but does not inform us about bolus flow. MII not only detects the presence of esophageal flow but also adds information on the direction of flow, duration of bolus presence, completeness of bolus clearance, and composition of a bolus.The combination of MII with manometry enables determination of the relationship between esophageal pressures and flow and, therefore, enhances evaluation of esophageal function in terms of assessment of mechanisms of esophageal volume clearance. In addition, this technique will improve our understanding of (patho)physiological mechanisms in pediatric GERD and other esophageal motility disorders.

Involvement of autonomic nervous activity changes in gastroesophageal reflux in neonates during sleep and wakefulness

“…The frequency of GER events observed in the present study was quite similar to that reported by van Wijk et al [20] in neonates with frequent regurgitation as detected by MII-pH monitoring (between 1.6 and 6 GER events per hour). The RI recorded in the present study (4%) is lower than the "abnormal" threshold of 7%…”

Esophageal impedance baselines in infants before and after placebo and proton pump inhibitor therapy

“…Esophageal multichannel intraluminal impedance is used for the detection of gastroesophageal reflux (GER) episodes in infants, children and adults (1)(2)(3). This is a technique to measure esophageal flow represented by changes in conductivity of adjacent contents between multiple electrode pairs on a catheter (4).…”

Detection of gastroesophageal reflux in children with cerebral palsy using combined multichannel intraluminal impedance-ph procedure

“…Multiple intraluminal impedance technique is based on the ionic concentrations of the luminal contents 6,10 . Bolus with no ionic contents, such as gas (air), results in a rise in impedance but relatively high ionic contents such as refluxate results in a drop in impedance.…”

“…This method detects reflux in the pH below 4, but GER episodes of weak acidity are not detected with this method. Neonates, infants and neurologically impaired children tend to have weak acid reflux because of the frequent feeding and neutralization of the gastric content following milk or formula [6][7][8] . Therefore, it is not possible to detect all reflux episodes with pH monitoring.…”