ISSN:0257-2753    

DOI:10.1159/000171235

出版商:S. Karger AG    

年代:1990

数据来源: Karger

摘要:

The most often used methods for the measurement of intragastric acidity are repeated mostly hourly aspirations of gastric contents or continuous pH measuring with an electrode. Intragastric pH, volume of aspirated gastric juice and total acid secretion have been tested over relatively short periods of time (2-12 h) and through an entire 24-hour period. Nearly every clinical antiulcer drug which neutralizes acidity or inhibits acid secretion has been investigated with this method. pH monitoring with the gastric aspiration procedure is a reliable and reproducible method. There is a remarkable global agreement in the results. While pH electrodes provide an alternative means of measuring pH, they have the disadvantage of not allowing measurement of volume and/or acid secretion.

ISSN:0257-2753    

DOI:10.1159/000171273

出版商:S. Karger AG    

年代:1990

数据来源: Karger

摘要:

The Royal Free Hospital protocol for simultaneous measurement of 24-hour intragastric acidity and plasma gastrin concentration is described in detail. The methods of analysing such data are discussed, with recommendations for a standard four-way analysis: median hourly 24-hour intragastric acidity or pH, or plasma gastrin concentration; integrated 24-hour intragastric acidity, or plasma gastrin concentration; analysis of integrated values according to meal-related intervals; and quantification of the percentage of time in a 24-hour period that intragastric pH is greater than 3.

ISSN:0257-2753    

DOI:10.1159/000171287

出版商:S. Karger AG    

年代:1990

数据来源: Karger

ISSN:0257-2753    

DOI:10.1159/000171236

出版商:S. Karger AG    

年代:1990

数据来源: Karger

摘要:

When a pH electrode is applied intragastrically for long-term pH metry, problems may occur which are related to the specific conditions of gastric juice and to the possible difference between the temperature of buffer solutions and the body temperature. The fact that pH electrodes measure the activity of the hydrogen ion instead of its concentration may, in concentrated solutions (i.e. pH < 2), lead to an error that is even compounded if other ions are present in high concentrations. This error normally does not influence comparisons between measurements obtained under the same conditions. It is, however, important to check which correction procedures are provided for the particular devices being used when comparing results obtained by different research groups. Calibration of the electrode at a temperature differing from body temperature may result in an important error. Complete correction for this error may be achieved for glass electrodes by a modified version of the Nernst equation; for monocrystalline antimony electrodes an empirically derived formula is available allowing for partial correction. In general, all types of electrodes should be calibrated using two different buffer solutions (one with a pH value between 6 and 8 and another with a pH of 2 or less) and the double-point interpolation method.

ISSN:0257-2753    

DOI:10.1159/000171275

出版商:S. Karger AG    

年代:1990

数据来源: Karger

ISSN:0257-2753    

DOI:10.1159/000171237

出版商:S. Karger AG    

年代:1990

数据来源: Karger

摘要:

Hourly averaged data from continuous intraluminal pH recording were compared with the point aspiration in five 24-hour studies performed on healthy volunteers. Two different electrode positions were compared simultaneously with aspiration. The correlation was performed using the median from the whole hour’s recording of the electrode against the aspiration point. There was a significant correlation between both electrodes and aspiration (p < 0.001), although both electrodes read consistently lower than aspiration: electrode A (gastric antrum), median pH = 1.4; electrode B (gastric body), pH = 1.9; aspiration, pH = 2.3. These findings show that data reported in clinical trials using different recording techniques are not directly comparable and must be interpreted appropriately. The position of the electrode may also be importan

ISSN:0257-2753    

DOI:10.1159/000171277

出版商:S. Karger AG    

年代:1990

数据来源: Karger

ISSN:0257-2753    

DOI:10.1159/000171238

出版商:S. Karger AG    

年代:1990

数据来源: Karger

摘要:

Based upon the results of in vitro studies, antimony electrodes are generally considered to have inferior electrochemical properties when compared with glass electrodes. Since a direct comparison in man is lacking, a 24-hour ambulatory intragastric pH recording was performed in 10 healthy male subjects simultaneously using glass and antimony electrodes. In the first set of experiments (when both electrodes were calibrated in buffers of pH 7 and 1 at 37 °C: beaker calibration) significantly lower pH recordings during fasting periods were registered with the antimony electrode. This difference could be corrected by a modified calibration, using the external skin reference electrode of the antimony electrode (finger calibration). In the second series of experiments (performed after finger calibration) comparable recordings of 24-hour intragastric pH could be obtained with antimony and glass electrodes in the same subjects. The reason for statistically insignificant differences of pH recordings with both electrodes in the early hours of the morning remains uncertain. The drift of glass and antimony electrodes did not differ. It is concluded from these data that, after adequate calibration, inferior electrochemical properties of antimony electrodes do not influence intragastric pH recordings in man

ISSN:0257-2753    

DOI:10.1159/000171278

出版商:S. Karger AG    

年代:1990

数据来源: Karger

ISSN:0257-2753    

DOI:10.1159/000171239

出版商:S. Karger AG    

年代:1990

数据来源: Karger