PH monitoring in the distal and proximal esophagus in symptomatic infants

Background: Standard distal esophageal pH monitoring data are sometimes wit hin normal ranges in children with clinically suspected gastroesophageal re flux disease. Therefore, the authors hypothesized that the amount of acid r eflux reaching the proximal esophagus may be greater in some subgroups of p atients than in healthy controls or in other subgroups of patients. Methods: The parameters of 24-hour pH monitoring in the proximal part of th e esophagus were analyzed in 120 symptomatic infants in who the reflux para meters in the lower esophagus were clearly within normal ranges (reflux ind ex < 5.0%). The infants were classified into four patient groups: excessive regurgitation (n = 41); inconsolable crying (n = 31), apparent life- threa tening event (ALTE) (n = 18), and chronic respiratory disorders (n = 30). T he control group consisted also of 120 infants. The following parameters we re calculated: reflux index, the number of reflux episodes, the number of r eflux episodes lasting longer than 5 minutes, the duration of the longest r eflux episode, and the acid clearance time (ACT, duration of reflux episode s divided by number of reflux episodes). Results: The patients with chronic respiratory disorders were significantly older than the patients in the other groups and the controls. In the dista l esophagus, there was no statistically significant difference between the reflux parameters. As could be expected, every parameter was statistically (paired t test, Wilcoxon signed-rank test) significantly smaller in the pro ximal than in the distal esophagus, except for the ACT in infants who prese nted with inconsolable crying. In the proximal esophagus, there was no stat istically significant difference between the different patient subgroups or controls: except for the number of reflux episodes in the group with chron ic respiratory disorders and the group with inconsolable crying. applying o ne-way analysis of variance. As determined by applying the Mann-Whitney tes t, the number of reflux episodes in the upper esophagus was significantly h igher in the group with chronic respiratory disorders than in the other pat ient groups and controls. Therefore, the authors' data do not support the h ypothesis that reflux reaching the proximal esophagus is a frequent cause o f ALTE. However, the data may suggest that the number of reflux episodes re aching the proximal esophagus in children with chronic respiratory disorder s and with distal pH monitoring data within normal ranges may be increased. Whether this finding reflects reality or a statistical coincidence: or is influenced by the older age of this patient group, needs further evaluation . Conclusions: In theory, dual simultaneous esophageal pH monitoring in the d istal and proximal esophagus may increase the diagnostic accuracy of pH mon itoring in infants. Our results do not support a substantial advantage of a systematic application of this new technique. especially not in infants pr esenting with ALTE, excessive regurgitation, or inconsolable crying. In the subgroup of patients with chronic respiratory disorders, more data are nee ded before conclusions can be determined and recommendations can be made.