Indications for 24-hour gastric pH monitoring with single and multiple probes in clinical research and practice

Abstract

The methodology of prolonged gastric pH monitoring has not yet been standardized with regard to the number and position of pH probes. Twenty-seven healthy volunteers and 11 patients affected by nonulcer dyspepsia have been submitted to 24-hr ambulatory simultaneous pH monitoring of the distal esophagus, fundus, and antrum. Fundic and antral pH profiles have been compared and causes of pH variations (pH > 4) identified. Both in healthy volunteers and dyspeptic patients, percentile curves of fundic and antral pH were statistically different in more than one of the daily periods considered (24-hr, postprandial, interdigestive, nocturnal). Percent time of duodenogastric reflux is significantly higher in the antrum than in the fundus in both groups. Modalities of gastric alkalinization secondary to food or duodenogastric reflux were different for the fundus and for the antrum both in healthy and dyspeptic subjects and between the two groups. These differences suggest that single and multiple pH monitoring of the stomach have different indications, and the position of the probes should vary according to the purpose of the test.

The surgical treatment of the intrathoracic migration of the gastro-oesophageal junction and of short oesophagus in gastro-oesophageal reflux disease1

“…Oesophageal manometry was performed according to our standard [11,16]. Since 1990 after performing the standard recording in the supine position according to the slow pullthrough technique, a second recording was performed in the sitting position, in order to favour the descent of the g -o junction with gravity).…”

“…The relationship between the LES (intrinsic component) and the diaphragmatic pinchcock (extrinsic components of the high pressure zone of the distal oesophagus) was assessed in both positions. Oesophageal or oesophago-gastric pH recording was performed according to techniques previously described [16].…”

Clinical relevance of esophageal and gastric pH measurements in patients with gastro-esophageal reflux disease (GERD)

“…As a consequence, some investigators claim that studies relying on a single intragastric pH electrode to quantitate gastric acidity are inaccurate 64 and that accurate measurement of gastric pH requires simultaneous recording from both the antrum and fundus 68 . The percentage time of duodenal reflux is also significantly higher in the antrum than in the fundus 69 . Again there is, therefore, some controversy as to whether a single intragastric probe pH monitoring is a reliable measure of duodenal reflux 68 .…”

“…Again there is, therefore, some controversy as to whether a single intragastric probe pH monitoring is a reliable measure of duodenal reflux 68 . Some researchers advocate the use of two probes, one in the fundus and the other in the antrum, to improve the accuracy of recordings 69 . The ingestion of food also affects gastric pH, resulting in an increase in pH that is greater in the fundus than the antrum 70 .…”

A functional study of the esophagus in patients with non-cardiac chest pain and dysphagia

“…A significant esophageal alkaline shift was defined as having occurred if the pH exceeded 4 (although this is an arbitrary value, it has been the most frequently used threshold value for identification of alkaline change). Total, upright and supine per cent times were calculated for oesophageal pH <4, gastric pH >4 and gastric bilirubin >0.14 (17)(18)(19)(20).…”