Combined esophageal and gastric pH-metry in healthy volunteers. Influence of cable through LES and effect of misoprostol.

In order to evaluate whether combined esophageal and gastric pH-metry is feasible without interference due to the transcardial cable, four 24-hr ambulatory esophageal pH-metries were carried out in seven healthy volunteers in a randomized order. In two studies only one glass electrode was used. It was placed 5 cm above the lower esophageal sphincter. In the two other studies an additional electrode was placed in the corpus region 10 cm below the lower esophageal sphincter. In order to obtain a wide range of pH values, misoprostol (400 micrograms) was given at 9 AM and 9:15 PM in two studies. In the two other studies placebo was given. Misoprostol exerted only a weak and short-lasting effect on gastric acidity. The four measuring conditions did not differ with respect to medians of esophageal reflux time and duration of single reflux episodes, Kendall's coefficient of concordance yielded a high reproducibility for both variables (P less than 0.0025). Thus, combined esophageal and gastric pH-metry is feasible and highly reproducible.