THE CLEARANCE OF GASTROESOPHAGEAL REFLUX IS INFLUENCED BY THE PRESENCE OF ACID REFLUX AND AGE

Abstract

Prolonged bolus contact time (BCT) and reduced clearance of gastroesophageal reflux (GER) are indicators of esophageal dysfunction. Aim: To investigate whether acid GER has an impact on the BCT/clearance of refluxate. Methods: 35 children (20M/15F, 2.5 wks-18.5 yr) underwent a 24 hr dual multichannel intraluminal impedance/pH studies. Children were divided into; group A (<2 yr, n = 20)and group B (>2 yr, n = 15). Each child was suspected of having GER-related symptoms. A pH study was considered abnormal or pH(+) if the pH was <4 for >6% in subjects >1 yr and >12% in subjects <1 yr old. BCT was defined as the duration (sec)of reflux in the most distal impedance channel. Clearance rates were expressed as mean BCT with confidence interval. Data were analyzed using analysis of variance. Results: pH studies were abnormal in 19 subjects (12 from group A, 7 from group B). Clearance of non-acid GER was more efficient in subjects with pH (+) in comparison to those with pH (−) {16.6[14.5, 19.1] vs 22.8[19.9, 26.1], p = .02} with no significant difference in the clearance of acid GER. The more efficient clearance of non-acid AGER in subjects with pH (+) was found in older children (p = 0.029), not in the younger group (p = .382). Among subjects with pH (+), older children had more effective clearance of GER than younger children {15.6[13.2, 18.5] vs 21.7[18.3, 25.7] p = .00059} and acid GER {16.1[12.8, 20.2] vs 24.5[19.5, 30.8] p = .00093}. In children with no evidence of abnormal acid reflux, there was no difference in the clearance of GER, acid GER and non acid GER between older and younger subjects. Conclusions: Older children with acid reflux tend to have more efficient volume clearance of GER and acid GER than younger ones. Regardless of age, volume clearance of non acid GER is more efficient in children with significant acidification of distal esophagus compared to control. In children younger than 2 years old, the presence or absence of acid reflux has no impact on the clearance of acid GER or non acid GER.