Gastric acidity and gastroesophageal reflux patterns in patients with esophagitis

Abstract

Esophageal pH-metry is the test of choice for diagnosing gastroesophageal reflux. However, although it allows acid refluxes to be distinguished, it is of limited value for identifying alkaline or mixed (acid mixed with alkaline material) refluxes. To evaluate the ability of dual pH-metry to identify alkaline or mixed refluxes, the gastric acidity and gastroesophageal reflux pattern were evaluated simultaneously in 64 patients with mild-moderate esophagitis, in 28 patients with severe or complicated esophagitis, and in 20 healthy subjects. A dual esophageal gastric pH-probe allowed three different types of esophageal reflux to be distinguished: (a) acid refluxes, defined as a drop in esophageal pH to values < 4 together with a gastric pH < 4; (b) mixed refluxes, defined as a drop in esophageal pH from baseline to values >; 4 associated with rises in gastric pH to > 4 values; (c) alkaline refluxes, defined as a rise in esophageal pH to > 7 associated with a simultaneous increase in gastric pH to > 4. Gastric acidity was more significantly reduced in patients with severe or complicated esophagitis than it was in healthy subjects (P < 0.01). The reflux pattern in both mild-moderate and severe esophagitis was characterized by mainly acid refluxes and a marked increase in the time the esophagus mucosa was exposed to acid (P < 0.001). Pure alkaline refluxes were rare (< 1%) in both healthy subjects and esophagitis patients. The number of mixed refluxes was considerably higher in severe esophagitis patients than it was in either mild-moderate esophagitis patients or controls (P < 0.05). The finding of mixed refluxes in severe or complicated esophagitis suggests that biliary acids and/or pancreatic enzymes are involved in the pathogenesis of severe forms of esophagitis.