title: Usefulness of combined gastric and esophageal pH monitoring in detecting gastroesophageal alkaline and mixed reflux.
abstract: 96 patients with 'typical' symptoms of gastroesophageal reflux were studied by means of combined gastric and esophageal pH monitoring. The aim was to assess the incidence of 'alkaline' and 'mixed' gastroesophageal reflux episodes as well as 'acid' reflux and their reciprocal relationship with esophagitis. 'Alkaline' gastroesophageal reflux was defined whenever the pH in the esophagus rose above 7, but only when there was a simultaneous or immediately previous rise of gastric pH to similar alkaline values resulting from duodenogastric reflux. 'Mixed' gastroesophageal reflux was defined whenever the pH in the esophagus dropped to 5.5-4.5, but only when there was a simultaneous or immediately previous rise of gastric pH above 4 related to duodenogastric reflux. Our data suggest that 'alkaline' gastroesophageal reflux is a rare phenomenon while 'mixed' gastroesophageal reflux episodes are present in 21% of these patients. 87% of patients with mixed reflux had esophagitis. Until analytical studies of refluxed material are available to clarify its composition, combined gastric and esophageal pH monitoring seems a useful test to correctly interpret the 'alkaline' and 'mixed' gastroesophageal reflux.
mesh_terms: D004942:Esophagitis, Peptic / Q000175:diagnosis*; D004947:Esophagus / Q000503:physiopathology; D005260:Female; D005745:Gastric Acidity Determination; D005764:Gastroesophageal Reflux / Q000175:diagnosis*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008875:Middle Aged