Clara M. Loots

Addition of pH-Impedance Monitoring to Standard pH Monitoring Increases the Yield of Symptom Association Analysis in Infants and Children with Gastroesophageal Reflux

OBJECTIVE To assess the additional yield of combined multichannel intraluminal pH-impedance (pH-MII) monitoring compared with standard pH monitoring on gastroesophageal reflux (GER) symptom associations in infants and children. STUDY DESIGN In 80 patients, 24-hour ambulatory pH-MII monitoring was performed. Tracings were analyzed with established pH-MII criteria. Symptoms of regurgitation and belching were excluded from analysis, because these were considered to be a direct consequence of GER. Standard GER-symptom correlation indices were calculated with: 1) standard pH monitoring; 2) MII detection of liquid and mixed bolus GER; 3) MII detection of all bolus GER (liquid, mixed, and gas); 4) pH-MII detection of all GER, including pH-only GER. RESULTS Fifty patients (21 children) were included. MII detection of all bolus GER yielded a significantly greater number of patients who were symptom-positive, 36 (72%) compared with 25 (50%) with standard pH-monitoring (P = .04). A positive symptom association was observed in 8 of 10 (80%) patients with pathological esophageal acid exposure and 28 of 40 (70%) patients with negative pH-findings. CONCLUSIONS A high proportion of patients with normal esophageal acid exposure had a positive symptom association on pH-MII monitoring. Including all MII-detected bolus GER and excluding pH-only GER for analysis optimizes the yield of GER-symptom associations in infants and children.

Measurement of mucosal conductivity by MII is a potential marker of mucosal integrity restored in infants on acid-suppression therapy.

Esophageal multichannel intraluminal impedance (MII) allows measurement of the conductivity of adjacent contents. During esophageal rest, raw impedance levels may represent mucosal integrity. We assessed the influence of proton pump inhibitors (PPIs) on presumed mucosal integrity by reanalyzing raw MII levels of 21 pH-MII tracings from infants with gastroesophageal reflux (GER) disease before and after esomeprazole treatment. Median (interquartile range) esophageal MII increased during treatment, 938 (652–1304) versus 1885 (1360–2183) Ohm, P < 0.0001. Patients with lower MII levels demonstrated a larger increase on therapy: Spearman r2 = 0.28, P = 0.014. No correlation with standard GER parameters was observed. In conclusion, PPI therapy increases MII levels in infants with symptomatic GER disease.

Esophageal impedance baselines in infants before and after placebo and proton pump inhibitor therapy

Background  Esophageal impedance monitoring records changes in conductivity. During esophageal rest, impedance baseline values may represent mucosal integrity. The aim of this study was to assess the influence of acid suppression on impedance baselines in a placebo‐controlled setting.

Evaluation of esophageal motility using multichannel intraluminal impedance in healthy children and children with gastroesophageal reflux.

Objective: Multichannel intraluminal impedance (MII) directly evaluates esophageal bolus transport. There is a good correlation between MII and manometry in healthy adults, but there are no reports concerning children. The aim of the present study was to determine normal values of esophageal motility using only impedance measurements in healthy children and in a pediatric population with gastroesophageal reflux (GER). Patients and Methods: We described in the present study 60 children submitted to pH-MII for 24 hours for suspected GER. Patients were divided into 2 different groups on the basis of their pH-MII report. Group 1 patients showed acid GER, whereas group 2 patients had negative pH-MII analysis for GER despite symptoms. We described impedance reflux and motility parameters on 10 standardized swallows: number of reflux, mean acid clearing time, median bolus clearing time, bolus presence time, total bolus transit time, segmental transit time, and total propagation velocity. Results: In group 1, the median mean acid clearing time was 151 seconds, whereas the median mean bolus clearing time was 25 seconds. In group 2 patients, all of the reflux parameters were normal. In group 1 the median bolus presence time at each measuring site, the median total bolus transit time, and the median segmental transit time were significantly greater and total propagation velocity lower than values reported in group 2 (P < 0.001), if compared with those described for adult patients. Conclusions: The pH-MII is an ideal test in children because it studies GER with its characteristics and motility pattern. Our report summarizes for the first time impedance motility parameters in healthy children.

Effect of lateral positioning on gastroesophageal reflux (GER) and underlying mechanisms in GER disease (GERD) patients and healthy controls.

Background  Posture has been shown to influence the number of transient lower esophageal sphincter relaxation (TLESRs) and gastroesophageal reflux (GER), however, the physiology explaining the influence of right lateral position (RLP), and left lateral position (LLP) is not clear. The aim of this study was to determine the influence of RLP and LLP on TLESRs and GERD after a meal in GER disease (GERD) patients and healthy controls (HC) while monitoring gastric distension and emptying.

Outcomes of endoscopy and novel pH-impedance parameters in children: is there a correlation?

Objectives: Discordance exists between outcomes of endoscopy, multichannel intraluminal impedance monitoring (pH-MII), MII baselines, and gastroesophageal reflux symptoms. The aim of the present study was to determine the association between endoscopy, pH-MII and MII baselines, in children with gastroesophageal reflux symptoms. Methods: Endoscopies were graded for reflux esophagitis (RE). Biopsies of the distal esophagus were assessed for signs suggestive of esophagitis. Reflux index (RI), symptom association probability (SAP), number of reflux episodes, and mean baseline values were calculated. pH-MII was considered positive in children when RI was ≥3% and/or SAP was ≥95% and for infants when RI was ≥10% and/or SAP was ≥95%. Baselines were manually calculated and compared with an automated analysis. For MII baselines, patients were divided in 3 groups: normal endoscopy and negative overall pH-MII; normal endoscopy and an overall positive pH-MII; and RE. Results: A total of 26 children and 14 infants were included, median age: 26.5 months (2 months–16.2 years). Thirteen (32.5%) had RE. A significant negative association was found for RI and MII baselines (P = 0.009) and between SAP and RE (P = 0.039, odds ratio 1.018). MII baseline values were predictive for neither conventional pH-MII parameters nor RE. Manual analysis and automated calculation of MII baselines showed a perfect correlation. Distal MII baselines were significantly lower in children with a positive overall pH-MII outcome compared with the proximal esophagus (P = 0.049). No significant changes were found in baselines among the different groups 1 to 3. Conclusions: Acid-related parameters are significantly related to MII baselines. A perfect correlation between manual- and automated analysis of MII baselines was found. Large prospective studies are needed to confirm the exact role of endoscopy and MII baselines.

Follow-up after pH-metry and pH impedance in pediatric gastroesophageal reflux disease.

Objectives: It is unclear how diagnostic tests for gastroesophageal reflux disease (GERD) in children relate to the course of symptoms during follow-up. Methods: During 1 year, all children (ages 0–18 years), who underwent pH-metry and/or pH multichannel intraluminal impedance (MII), were included after written informed consent was obtained. pH-metry and pH-MII test characteristics, such as reflux index (RI, % time that esophageal pH < 4), were obtained from the measurements. A questionnaire containing subcategories (medical history, gastrointestinal [GI] symptoms, extraesophageal symptoms, symptom burden, and therapeutic agents) was used; subjects were asked to fill the questionnaire at the time of inclusion and 3, 6, and 12 months afterward. Results: A total of 162 infants and 42 children were included. pH-MII was performed in 15.4% and 57.4% of infants and children, respectively. All of the other subjects underwent pH-metry. Median RI was 2.0% (interquartile range 3.4) in infants and 1.7% (interquartile range 2.3) in children. RI was considered positive in 6.8% and 12.8% of infants and children, respectively. In infants, RI at baseline was significantly associated with symptom burden at baseline and at 3 and 12 months of follow-up. RI at baseline and reported GI symptoms at 3 months were also significantly associated. In infants and children using medication, symptom burden was significantly higher compared with those not using medication. This difference was found at baseline, after 3 and 12 months. Conclusions: In infants, an initial high RI is associated with persistence of GI symptoms at 3 months and a higher burden of symptoms during the course of 1 year. In children there were no such findings.

An expert panel-based study on recognition of gastro-esophageal reflux in difficult esophageal pH-impedance tracings.

Despite existing criteria for scoring gastro‐esophageal reflux (GER) in esophageal multichannel pH‐impedance measurement (pH‐I) tracings, inter‐ and intra‐rater variability is large and agreement with automated analysis is poor. To identify parameters of difficult to analyze pH‐I patterns and combine these into a statistical model that can identify GER episodes with an international consensus as gold standard.

New Insights in Gastroesophageal Reflux, Esophageal Function and Gastric Emptying in Relation to Dysphagia Before and After Anti-Reflux Surgery in Children

In children with gastroesophageal reflux (GER) disease refractory to pharmacological therapies, anti-reflux surgery (fundoplication) may be a treatment of last resort. The applicability of fundoplication has been hampered by the inability to predict which patient may benefit from surgery and which patient is likely to develop post-operative dysphagia. pH impedance measurement and conventional manometry are unable to predict dysphagia, while the role of gastric emptying remains poorly understood. Recent data suggest that the selection of patients who will benefit from surgery might be enhanced by automated impedance manometry pressure-flow analysis (AIM) analysis, which relates bolus movement and pressure generation within the esophageal lumen.