24-hour esophageal pH monitoring in children with pathological acid gastroesophageal reflux: primary and secondary to food allergy. Part I. Intraesophageal pH values in distal channel; preliminary study and control studies--after 1, 2, 4 and 9 years of clinical observation as well as dietary and pharmacological treatment.

PURPOSE

Among 264 children suspected of GERD, acid gastroesophageal reflux (GER) was confirmed in 138 children on the basis of 24-hour pH monitoring.

AIMS OF THE STUDY

Comparative analysis of parameters of 24-hour intraesophageal pH monitoring (in distal channel--above cardia) in children with acid GER: primary and secondary to cow milk allergy and/or other food allergy (CMA/FA) diagnosed; comparison of examined values of pH monitoring parameters with regard to duration of the disease (preliminary study and prospective studies--after 1, 2, 4 and 9 years of clinical observation and/or conservative treatment).

MATERIAL AND METHODS

264 children suspected of GERD, of both sexes (140 boys--53.0% and 124 girls--47.0%), aged: 1.5-102 months; x = 20.78 +/- 17.23 months, were enrolled in the study. In order to differentiate acid GER: primary from secondary to CMA/FA in 138 (52.3%) children with GERD immunoallergological tests were performed. Positive result of oral food challenge test confirmed the allergy being the cause of GER. 138 children with pathological acid GER were qualified into two groups: 1 and 2. Group 1--76 patients (55.1%), aged: 4-102 months; x = 25.2 +/- 27.28 months, with pathological primary GER. Group 2--62 patients (44.9%), aged: 4-74 months, mean age x = 21.53+/- 17.79 months, with pathological GER secondary to CMA/FA.

RESULTS

Significant differentiation of the mean values of these parameters between preliminary study and control studies within groups was shown in the case of: number of episodes of acid GER and episodes of acid GER lasting more than 5 minutes, duration of the longest episode of acid GER, acid GER index: total and supine (distal channel). Statistical significance (p < 0.05) was higher in group 1, especially during prospective clinical observation and/or conservative treatment. At the same time significant differentiation of the mean values of: number of episodes of acid GER and episodes of acid GER lasting more than 5 minutes and mean values of acid GER index: total and supine was shown between the groups. Statistical significance (p < 0.05) was higher in group 2.

CONCLUSIONS

The preliminary study of examined children confirmed that values of pH monitoring in distal channel were comparable and did not contribute to differentiation of GER into primary (group 1) and secondary (group 2). During prospective clinical observation and/or clinical treatment the intensity of reflux in these groups was assessed on the basis of the number of episodes of acid GER and episodes of acid GER lasting more than 5 minutes in distal channel. Acid GER index: total and supine appeared to be important diagnostic parameter but only after the first year of dietary and pharmacological treatment.