Reproducibility of 24-Hour Combined Multiple Intraluminal Impedance (MII) and pH Measurements in Infants and Children. Evaluation of a Diagnostic Procedure for Gastroesophageal Reflux Disease

Abstract

Gastroesophageal reflux disease (GERD) is a common disease in infants and children. Prolonged (24-hr) pH monitoring in the esophagus for determination of increased acid exposure has, together with endoscopy, been the only routinely implemented method for GERD diagnosis. The recently introduced multiple intraluminal impedance (MII) provides additional information about the number of both acid and nonacid episodes of retrograde bolus movement in the esophagus. The aim of this study was to investigate the day-to-day reproducibility and the interobserver variability of 24-hr combined MII (number of nonacid and acidic reflux episodes) and pH in the esophagus in infants and children. Upper endoscopy followed by 2 x 24-hr consecutive combined MII and pH monitoring was performed in 33 infants and children referred to a tertiary center for evaluation of GERD. The study was performed in a hospital setting without dietary restrictions. Bland-Altman difference versus mean plots and calculation of the limits of agreement (LOA) were used for assessment of the reproducibility of the total number of acidic and nonacidic reflux episodes. LOA for the number of acidic reflux episodes on day 2 were 0.2-5.3 times the value obtained on day 1. For the total number of nonacidic reflux episodes, LOA were 0.04-8.6; for the total number of reflux episodes, 0.3-3.3. An abnormal reflux index on one or both recording days was found in 7 of 30 patients. In conclusion, considerable day-to-day variability was found for nonacidic reflux episodes. Less variability was found for acidic reflux episodes. This variability must be taken into consideration for the use of MII in the clinical evaluation of infants and children with GERD.

Effect of acid suppression therapy on gastroesophageal reflux and cough in idiopathic pulmonary fibrosis: an intervention study

“…A combination of the small sample size and day to day variations in reflux frequency [39] may explain the unexpectedly low rates of acid reflux observed in our population compared with previous larger studies [7,40]. In addition, a previous study has shown that objective cough frequency and subjective cough severity are both reduced by the presence of an oesophageal catheter [41].…”

Comparison of multichannel intraluminal impedance-pH monitoring and reflux scintigraphy in pediatric patients with suspected gastroesophageal reflux

“…This is especially important for patients with pulmonary symptoms as shown in some studies[48]. Dalby et al[49] stated that MII/pHM can detect all refluxes (acidic/nonacidic), content of the refluxes, association of symptoms and reflux episodes with high reproducibility. By the addition of MII in our study, the number of patients diagnosed as having GERD increased by 50%.…”

Impedance and extraesophageal manifestations of reflux in pediatrics

“…As MII‐pH continues to become the gold standard and more studies are performed on pediatric patients, it will make both the acquisition of the norms easier as well as more necessary. It is important to note that, although reproducible, MII‐pH findings do vary from day to day, and it is possible that some associations were missed based on the short duration of the study and normal daily variations in acid and nonacid reflux events 12…”