[Indications and limitations of 24-hour gastric pH-metry. Personal experience]

After a brief introduction regarding 24-hours gastric pH monitoring and a description of the instruments used, indications and the analysis of findings, the authors report their personal experience based on the study of 4 groups of subjects (healthy, hyersecretory, hyposecretory, dyspeptic). The analysis of pH-metries observed in these subjects show that 24-hour monitoring of gastric pH is a reliable method for assessing hypersecretion or hyposecretion of gastric acidity, whereas it is only of relative importance in essential dyspepsia. The authors therefore indicate the parameters to be taken into account in the evaluation of pH-metry findings in hypersecretory patients: 1) the percentage time of which pH is less than 1 (mean value 46.20 +/- 28.2);2) the pH pattern assessed according to the circadian rhythm which shows a prandial and post-prandial tamponade which is lower than normal with a rapid return of pH to extremely low values; 3) the visual graphic assessment for an overall judgement of pH patterns; and in hyposecretory patients: 1) the percentage time for which pH is higher than 7 (mean value 47.92 +/- 52.08); 2) enhanced pH levels ranging between 0 and 4 (mean percentage 9.67 divided by 27.08); 3) pH values at times 0, 1, 2, 3 which confirm hyposecretion in the meal causes a marked and long-lasting tamponade with pH levels above 6-7. Even in these cases the visual graphic assessment is important for an overall definition of 24-hour ph patterns.