Reproducibility and physiological characteristics of 24-hour ambulatory esophangeal manometry/pH-metry

To assess the reproducibility and physiological characteristics of ambulatory esophageal manometry/pH-metry.

Ten healthy volunteers were studied on two separate occasions (2 wk apart) using the Synectics Microdigitrapper System. The pH recording failed in one subject; thus, pH data were analyzed in nine, and motility measurements in all 10 subjects.

A high degree of reproducibility was established for the five pH and seven manometry variables assessed. Using the paired t test and Wilcoxon signed rank test to compare the two sets of data, all p values were >0.05. Narrow 95% confidence intervals containing the zero measures were also obtained on the differences of the data from both sessions for all variables. Better correlation coefficients were obtained for the motility parameters than for the pH parameters. As would be expected, reflux occurred more often in the upright than in the supine position. Furthermore, esophageal contractions were of higher amplitude and longer duration in the distal esophagus, and the frequency of propulsive contractions sequences was higher during meals and in the upright position than in the supine position.

This study demonstrates the reproducibility of ambulatory esophageal manometry/pH-metry, suggesting that this technology may be useful in assessing the effect of pharmacological intervention on esophageal motor function.