Tolerance and reliability of wireless pH monitoring in children

The purpose of this study was to determine whether the placement of a wireless capsule pH monitoring system improved the reproducibility and patient comfort of pH probe studies in children.

The records of 50 children who underwent wireless pH monitoring were retrospectively reviewed. Among this group, 44 children (27 males and 17 females) met inclusion criteria. The average age was 11.8 years, with a range from 6 years to 19 years. Each of these patients had a capsule placed 6 cm above the squamocolumnar junction and underwent pH telemetry for 2 days. In addition, 38 of the 44 families were contacted for follow-up to determine the tolerability of the catheter-free monitoring.

Data analysis revealed that the overall reproducibility of a single 24 hour period was 77%. Studies were considered reproducible if the reflux index was normal (pH <4 for less than 5% of study period) or abnormal on both study days. Using McNemar's exact test, we found no significant difference between the two days (P = 0.11). Ten of 44 patients had conflicting results on day 1 compared with results on day 2. The majority (68%) of patients reported some degree of discomfort during the study; however, this pain was generally mild. Ninety-five percent of parents would be willing to have their child undergo pH monitoring in the future with the wireless pH monitoring.

Catheter-free prolonged esophageal pH monitoring is feasible in children older than 6 years of age. A lack of consistent reproducibility in sequential 24 hour recordings with this technique concurs with findings using the conventional catheter methodologies. The catheter-free system is often associated with discomfort during the study, but these symptoms were generally well tolerated.