How Best to Estimate Insertion Length of Multichannel Intraluminal Impedance pH Probes in Children.

OBJECTIVE: To assess the reliability of the KidZ Health Castle formula (KHC-F) to determine the correct probe position of a multichannel intraluminal impedance pH. STUDY DESIGN: A retrospective cohort study was performed on 222 children between 1 month and 18 years of age undergoing multichannel intraluminal impedance pH. The primary outcome was the comparison of the pH sensor location determined by the KHC-F with the radiological target position. The margin of error was defined as 1 cm from the target position. Performance of the KHC-F and existing formulas was determined via the percentage with a correct position, mean error, 95% limits of agreement (Bland-Altman plots), and Spearman correlation. A post hoc analysis was performed with an updated KHC-F v2, subtracting -0.5 cm from the KHC-F. RESULTS: Positioning with KHC-F was correct in two-thirds of the participants, with a very strong correlation (ρ = 0.91) with the target position. Bland-Altman plots showed good agreement between KHC-F and target position (mean error of -0.44 cm, lower limit -3.2 cm, upper limit 2.3 cm). A post hoc analysis with the KHC-F v2 showed a correct positioning in 74% of patients. Comparison with other formulas showed a stronger performance of KHC-F and KHC-F v2 on correct positioning, mean error, and 95% limits of agreement. CONCLUSIONS: The KHC-F leads to reliable results. KHC-F v2 outperforms all other existing formulas in children, thereby reducing the need for repositioning and the amount of x-ray exposure. The age distribution of the sample may be a limitation, as well as the retrospective nature of the study.

Delayed Analysis of Hydrogen-Methane Breath Samples.

PURPOSE: Hydrogen-methane breath tests are used to diagnose carbohydrate malabsorption and small intestinal bacterial overgrowth. The COVID-19 pandemic has driven the modification of procedures as breath tests are potentially aerosol-generating procedures. We assessed the effect of delayed analysis of breath samples, facilitating the at-home performance of breath testing. METHODS: Children provided two breath samples at every step of the lactose breath test. The samples were brought back to the clinic, and one set of samples was analyzed immediately. The second set was stored at room temperature and analyzed 1-4 days later. RESULTS: Out of the 73 "double" lactose breath tests performed at home, 33 (45.8%) were positive. The second samples were analyzed 20 to 117 hours after the first samples (41.7±24.3 hours). There was no significant difference in the hydrogen concentration between the first and second sets (Z=0.49, p=0.62). This was not the case for methane, which had a significantly higher concentration in the second breath samples (Z=7.6). CONCLUSION: Expired hydrogen levels remain stable in plastic syringes if preserved at room temperature for several days. On the other hand, the delayed analysis of methane appeared to be less reliable. Further research is needed to examine the impact of delayed analysis on methane and hydrogen concentrations.

Distress in Infants and Young Children: Don't Blame Acid Reflux.

OBJECTIVE: The role of gastroesophageal reflux (GER) causing distress in infants is controversial but acid inhibitors are often empirically prescribed. We evaluated the relation between distress assessed by the Face, Legs, Activity, Cry, Consolability (FLACC) scale and GER in infants. METHODS: We analyzed multiple intraluminal impedance-pH (MII-pH) monitoring tracings of infants with persistent unexplained fussiness or distress. Symptoms occurring during investigation were scored by parents using the FLACC scale and were grouped as "distress" episodes. RESULTS: We recruited 62 children (ages 15 days to 23 months, median age 3.5 months). During MII-pH, 452 episodes of distress were registered: 217 (48%) were temporally associated with GER and 235 (52%) were not, with no difference in the median value of FLACC between the 2 groups. Infants with abnormal acid exposure index had a significantly lower FLACC compared with the group with acid reflux index <7% (P < 0.001). When associated with symptoms, GER occurred significantly more often before than simultaneously or after an episode of distress (P = 0.001). Age, proximal extension, and duration of GER did not correlate with FLACC scores. Episodes of distress associated with nonacid reflux presented a significant higher FLACC compared with the ones with acid content (FLACC 6 vs 5, P = 0.011). In infants, episodes of distress do not significantly correlate with GER. CONCLUSIONS: No difference in infant distress was noted between proximal and distal GER. Non-acid reflux is perceived at least as painful than acid GER. Our results stress that acid inhibitors should not be started in infants presenting distress unless a clear association with acid GER is demonstrated.

The Effect of Alginate in Gastroesophageal Reflux in Infants.

BACKGROUND: Guidelines are contradictory regarding the use of alginate in infants with persisting gastroesophageal reflux (GER). While The British National Institute for Health and Care (NICE) guidelines consider alginate as a treatment option, the guidelines of the European and North-American Societies for Pediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN, NASPGHAN) do not recommend alginates. AIMS: We assessed the efficacy of alginate to reduce GER episodes in infants. METHODS: In a prospective, observational study, we consecutively enrolled all infants referred for pH-multiple intraluminal impedance (pH-MII) recording because of persisting GER symptoms not responsive to behavior and dietetic modifications. A 48-h pH-MII was performed in all infants; a baseline recording was performed during the first 24 h while magnesium or sodium alginate was administered during the second 24 h. The primary endpoint was the difference in the total number of GER episodes per 24 h between the baseline day and the second day during which the alginate was administered. The secondary outcome was the difference in symptoms between each period. We also compared other pH-MII data from before and during alginate administration. RESULTS: We recruited 43 infants (median age 68 days, range 25-306); three pH-MII tracings were excluded because of artifacts. The median number of all MII reflux episodes was significantly reduced during alginate administration (76.0 vs 69.5; p < 0.001). Crying-fussiness, cough and regurgitation episodes all significantly improved during alginate administration (p = 0.00012; p = 0.005 and p = 0.04, respectively). The following MII parameters also decreased during the alginate administration: acid (19.0 vs 14.5; p < 0.04), non-acid (52.0 vs 49.5; p < 0.004), proximal GER episodes (46.0 vs 41.4; p < 0.007), and bolus exposure index (1.9 vs 1.6; p = 0.002). At least three out of seven pH-MII parameters decreased by > 10% during the alginate period in 31/40 infants (77.5%), without a significant difference between magnesium and sodium alginate. CONCLUSION: These results suggest that alginate significantly decreases the number and extension of both acid and non-acid reflux episodes and associated symptoms in infants.