Continuous 20-24 hr Esophageal pH-monitoring in infancy.

With the aid of a specially designed combination electrode for infants, 20-24 hr monitoring of esophageal pH was undertaken in 15 infants, aged 5 wk-11 mo. Results demonstrated that the reflux time pH less than or equal to 4 was valid for this age group as for adults, to differentiate between physiologic and pathologic reflux. A new parameter, that of clearance time, defined as normalization time required to return to initial pH, was introduced to improve pH assessment. Both parameters showed a highly significant correlation in relation to each other, and were consistently in accord with the clinical symptoms.