Relationship between gastro-oesophageal reflux and gastric activity in newborns assessed by combined intraluminal impedance, pH metry and epigastric impedance

The pathogenesis of gastro-oesophageal reflux disease (GORD) is complex and multifactorial. A motility disorder resulting from immaturity of the gastro-oesophageal tract may be involved. We have combined multichannel intraluminal impedance (MII) and pH monitoring with epigastric impedance (EGI) to evaluate the activity of this tract in neonates with suspected GORD. Multichannel intraluminal impedance, pH and EGI were followed for 3 h in 30 newborns displaying apparent life-threatening events and signs of GORD. Simultaneous application of MII and pH monitoring identifies reflux episodes and illustrates their duration, height and pH. Episodes detected by MII were placed on the EGI curve and the contemporaneous gastric filling state and emptying velocity were calculated. During the total measuring time, 248 reflux episodes were revealed. An inverse correlation was evident for reflux frequency and gastric emptying velocity (r(2) = 0.94; P < 0.001), and between acid refluxes and the gastric filling state (r(2) = 0.95; P < 0.001), whereas a positive correlation was found between the reflux level and the gastric filling state (r(2) = 0.52; P < 0.05). Simultaneous MII, pH and EGI monitoring provided new information on the relationship between refluxes and gastric activity. Data suggest that gastric emptying patterns influence the frequency, level and pH of reflux episodes.