PURPOSE: The aim of this study was to evaluate bolus transit during esophageal swallow (ES) and gastroesophageal reflux (GER) events and to investigate the relationship between the characteristics of ES and GER events in a population of term and preterm newborns with symptoms of gastroesophageal reflux disease (GERD). METHODS: The study population consisted of term and preterm newborns referred to combined multichannel intraluminal impedance (MII) and pH monitoring for GERD symptoms. The frequency and characteristics of ES and GER events were assessed by two independent investigators. Statistical significance was set at p<0.05. RESULTS: Fifty-four newborns (23 preterm) were included in the analyses. Median bolus head advancing time corrected for esophageal length (BHATc) was shorter during mealtime than during the postprandial period (median, interquartile range): 0.20 (0.15-0.29) s/cm vs. 0.47 (0.39-0.64) s/cm, p<0.001. Median bolus presence time (BPT) was prolonged during mealtime: 4.71(3.49-6.27) s vs. 2.66 (1.82-3.73) s, p<0.001. Higher BHATc (p=0.03) and prolonged BPT (p<0.001) were observed in preterm newborns during the postprandial period. A significant positive correlation between BHATc and bolus clearance time was also observed (rho=0.33, p=0.016). CONCLUSION: The analysis of ES and GER events at the same time by MII provides useful information to better understand the physiopathology of GERD. In particular, the analysis of BHATc during the postprandial period could help clinicians identify newborns with prolonged esophageal clearance time due to impaired esophageal motility, which could allow for more accurate recommendations regarding further tests and treatment.
Electric Impedance* ; Gastroesophageal Reflux* ; Head ; Humans ; Hydrogen-Ion Concentration ; Infant, Newborn* ; Meals ; Postprandial Period ; Premature Birth ; Research Personnel

Background/Aims: Combined multichannel intraluminal impedance and pH monitoring (MII/pH) is considered the most accurate test to detect gastroesophageal reflux (GER), however lacking reference values. We aim to determine reference values for the pediatric population and to correlate these values with age and postprandial/fasting period. Methods: We evaluated MII/pH traces from patients (newborns, infants, and children) admitted to 3 Italian hospitals and who underwent MII/ pH for suspected GER disease. Patients with MII/pH traces that showed significant symptom-reflux associations and/or a pathological reflux index (> 6% for newborns and infants, > 3% for children) were excluded. Traces were analysed in their entirety, and in the postprandial period (first hour after a meal) and the fasting period (the following hours before the next meal) separately. Results: A total of 195 patients (46 newborns, 83 infants, and 66 children) were included. Age positively correlated with frequency of acidic GER events (r = 0.37, P < 0.05) and negatively associated with weakly acidic GER events (r = 0.46, P < 0.05). Conclusions This study describes the distribution of MII/pH values in a pediatric population with normally acidic GER exposure and no significant association between GER events and symptoms. These MII/pH values may be used as reference values in clinical practice for a corrected GER disease diagnosis in the pediatric population.