A baseline impedance analysis in neurologically impaired children: A potent parameter for estimating the condition of the esophageal mucosa

Clinical characteristics of children with severe neurologic impairment: A scoping review

OBJECTIVE

The aim of this study is to extrapolate the clinical features of children with severe neurologic impairment (SNI) based on the functional characteristics and comorbidities described in published studies.

METHODS

Four databases were searched. We included studies that describe clinical features of a group of children with SNI (≥20 subjects <19 years of age with >1 neurologic diagnosis and severe functional limitation) using data from caregivers, medical charts, or prospective collection. Studies that were not written in English were excluded. We extracted data about functional characteristics, comorbidities, and study topics.

RESULTS

We included 102 studies, spanning 5 continents over 43 years, using 41 distinct terms for SNI. The terms SNI and neurologic impairment (NI) were used in 59 studies (58%). Most studies (n = 81, 79%) described ≥3 types of functional characteristics, such as technology assistance and motor impairment. Studies noted 59 comorbidities and surgeries across 10 categories. The most common comorbidities were related to feeding, nutrition, and the gastrointestinal system, which were described in 79 studies (77%). Most comorbidities (76%) were noted in <10 studies. Studies investigated seven clinical topics, with "Gastrointestinal reflux and feeding tubes" as the most common research focus (n = 57, 56%). The next most common topic, "Aspiration and respiratory issues," included 13 studies (13%). Most studies (n = 54, 53%) were retrospective cohorts or case series; there were no clinical trials.

CONCLUSIONS

Despite the breadth of described comorbidities, studies focused on a narrow set of clinical topics. Further research is required to understand the prevalence, clinical impact, and interaction of the multiple comorbidities that are common in children with SNI.

Low Mean Nocturnal Baseline Impedance is Associated With a Pathological Acid Exposure Time in Children

BACKGROUND

The baseline impedance (BI) and the mean nocturnal baseline impedance (MNBI) serve as markers of mucosal integrity in patients with pathologic acid exposure time (AET). This work aims to investigate the association between the BI and MNBI with the AET in children.

METHODOLOGY

A retrospective study was performed in children ≤18 years old with suspicion of gastroesophageal reflux disease who underwent both endoscopy and pH-impedance monitoring (pH-MII). Esophagitis was graded according to the Los Angeles classification. The pathological AET was determined depending on the age (≥5% in patients >1 year and ≥10% in those ages ≤1 year). For the BI, 60 s measurements were taken every 4 h, and for the MNBI, 3 10 min measurements were taken between 1.00 and 3:00 am; then, they were averaged. The means of BI and MNBI were compared with each other, with the AET, and other variables.

RESULTS

Sixty-eight patients were included, 25% of patients presented pathological AET. The mean of the MNBI was higher than BI in channels 6 (2195 vs 1997 Ω, P = 0.011) and 5 (2393 vs 2228 Ω, P = 0.013). BI and MNBI at channel 6 were lower in patients with pathological AET than in those with normal AET (1573 vs 2138 Ω, P = 0.007) and (1592 vs 2396 Ω, P = 0.004), respectively.

CONCLUSIONS

Children with pathological AET had lower impedance values than those with normal AET. BI and MNBI measurements should be part of the routine MII-pH assessment in children.

Oesophageal pH-Impedance for the Diagnosis of Gastro-Oesophageal Reflux Disease: Validation of General Population Reference Values in Children with Chronic Neurological Impairments

Diagnosis of gastro-oesophageal reflux disease (GORD) in children with chronic neurological impairment (NI) remains a clinical challenge. The study aimed to validate the relevance of the reference values used to assess gastro-oesophageal reflux (GOR) in children with NI and to determine the optimal cut-off level of the pH-impedance parameter with the best predictive value for outcomes associated with endoscopic assessments of the oesophagus. Sixty-seven children (32 male, 35 female; age: interquartile range, 5 years 6 months-14 years 10 months; median, 11 years 3 months) with NI were prospectively recruited for the study. The exclusion criteria were previous fundoplication and lack of consent for the study. All patients underwent evaluations for GOR disease, including pH-impedance and gastroscopy. Based on endoscopy, oesophagitis was diagnosed in 22/67 children (32.8%); 9/67 (13.4%) were classified as having Hetzel-Dent grade III or IV. GOR was present in 18/67 children (26.9%), as determined by pH-impedance. Patients with endoscopic lesions had a significantly higher number of total reflux (p = 0.0404) and acidic episodes (p = 0.0219). The total number of reflux episodes, with a cut-off level of 44 episodes, was the pH-impedance parameter most strongly predictive of the presence of lesions in gastroscopy (specificity: 50%, sensitivity: 73%). These findings suggest that endoscopic lesions may be present in children with chronic NI with a low number of GOR episodes, as recorded by pH-impedance. The use of standardised reference norms determined for the general population may underestimate GOR episodes in this group of patients.

Simultaneous Evaluation of Laryngopharyngeal Reflux and Swallowing Function Using Hypopharyngeal Multichannel Intraluminal Impedance Measurements in Neurologically Impaired Patients

Background/Aims

This study aims to evaluate the presence of laryngopharyngeal reflux (LPR) and to investigate the use of hypopharyngeal baseline impedance (BI) for assessing swallowing dysfunction and gastroesophageal reflux disease (GERD) using hypopharyngeal multichannel intraluminal impedance and pH (HMII-pH) monitoring in neurologically impaired patients (NIPs).

Methods

The study population in this retrospective study comprised 20 NIPs (mean age, 36.1 ± 15.0 years; age range, 13-64 years) who underwent multichannel intraluminal impedance and pH (MII-pH), HMII-pH, and laryngoscopy using the Hyodo scoring method from December 2016 to April 2019. The MII-pH and HMM-pH parameters were compared in the NIPs, whereas hypopharyngeal BI values were compared between NIPs with ≥ 5 and < 5 in Hyodo scores. Correlations between the hypopharyngeal BI values and the Hyodo score were analyzed using Spearman’s correlation coefficient. A receiver operator characteristic curve was created to determine the optimum cut-off of hypopharyngeal BI value to discriminate SD.

Results

Three NIPs were diagnosed with pathological LPR and GERD by the HMII-pH monitoring. No significant differences in parameters were observed between MII-pH and HMII-pH monitoring. The correlation analysis demonstrated a significant negative correlation between the hypopharyngeal BI values and Hyodo scores. The optimal cutoff value for hypopharyngeal BI was 1552 Ω.

Conclusions

This study demonstrated the usefulness of HMII-pH monitoring in identifying NIP with pathological LPR. Considering the difficulties in performing examinations in NIPs, HMII-pH monitoring may be a potentially useful technique for the simultaneous evaluation of swallowing dysfunction, LPR, and GERD in NIP.

Acid and bolus exposure in pediatric reflux disease according to the presence and severity of esophageal mucosal lesions

PURPOSE

The relationship between reflux index (RI) and bolus exposure parameters in multichannel intraluminal impedance (MII) has not been examined sufficiently among children. The significance of acid and bolus exposure in evaluating pediatric reflux disease (RD) was explored by focusing on mucosal lesions.

METHODS

We conducted MII-pH on 28 patients (median age 8 years) with suspected RD. We assessed relationships between RI and bolus exposure indices, and also compared acid and bolus exposures across patients grouped by endoscopic esophageal mucosal lesions.

RESULTS

RI correlated significantly with distal acid reflux events (r = 0.60), acid bolus exposure time (BET) (0.55), and bolus clearance time (BCT) (0.48). Significant differences were observed among the control, non-erosive RD (NERD), and erosive RD (ERD) groups in all acid and several bolus exposure indices (distal and proximal frequencies, and BCT), while no significant difference was apparent between NERD and ERD. Acid exposure tended to be more severe in high-grade than in low-grade ERD, while no similar tendency was found in any bolus parameters other than BCT.

CONCLUSIONS

MII-pH showed great potential for investigating the pathophysiology of pediatric RD, with RI revealing different correlations with variable bolus exposure indices. However, no specific parameters allowing precise discrimination between RDs or mucosal severities were identified.

Standard protocol devised by the Japanese Pediatric Impedance Working Group for combined multichannel intraluminal impedance-pH measurements in children

Multichannel intraluminal impedance-pH measurements (MII-pH) are useful for evaluating acid and non-acid gastroesophageal reflux (GER). However, the use of MIH-pH is not yet established in Japan. The Japanese Pediatric Impedance Working Group (Japanese-PIG) convened to devise a standard protocol for MII-pH in Japanese children. The expert members of the Japanese-PIG collected data on pediatric MII-pH from the relevant literature in English, including the standard protocol of MII-pH presented by the European PIG, and the insights of international experts. The resultant consensus was included in the contents of the standard protocol of MII-pH. The standard protocol included standardization of the indication, methodology, and interpretation of MII-pH in Japanese children. The criteria for abnormal GER by MII-pH were defined using the Reflux Index and number of total reflux episodes independently in children aged < 1 year and those aged ≥ 1 year. Moreover, a significant relationship between GER and symptoms was identified using the symptom index and symptom association probability approach. We conclude that the current version of the protocol for MII-pH is tentative because it is not based on data from Japanese children. Further studies are needed to render this protocol clinically beneficial and expand its use in Japan.

Analyses of the relationship between a 'number of reflux episodes' exceeding 70 and the pH index in neurologically impaired children by evaluating esophageal combined pH-multichannel intraluminal impedance measurements

BACKGROUND

The present study aimed to evaluate the characteristics associated with a number of reflux episodes (NoRE) of 70 by comparing the clinical and multichannel intraluminal impedance pH measurements (pH/MII) and pH index (pHI) in neurologically impaired (NI) children.

PATIENTS AND METHODS

NI children (1-16 years of age) in whom pH/MII had been measured for GERD study were enrolled in this study. All children were divided into NoRE >70 or ≤70 and pHI >4.0 or ≤4.0, >5.0 or ≤5.0 or >7.0 or ≤7.0. In addition, the NI children with pHI >4.0, >5.0 and >7.0 were subdivided into NoRE >70 and ≤70 groups. The clinical and pH/MII measurements were compared between each of the two groups. The cutoff values of pHI and baseline impedance (BI) (Z6) were calculated to discriminate NoRE >70 and ≤70.

RESULTS

A total of 61 NI children were enrolled in this study. There was a significant difference in the acid-related parameters, the NoRE (nonacid) and BI between NoRE >70 and ≤70, acid-related parameters and BI between pHI >4.0 and ≤4.0, >5.0 and ≤5.0 and >7.0 and ≤7.0 groups. Furthermore, a significant difference was still observed in the BI between NoRE >70 and ≤70 groups among patients with pHI >4.0, >5.0 or >7.0. The cutoff values of pHI and BI (Z6) for discriminating NoRE >70 and ≤70 were 9.2 and 1049Ω, respectively.

CONCLUSION

The present study indicates that NoRE 70 corresponds to GERD in which patients suffer severe acid exposure with pH of around 9% and esophageal mucosal damage with low BI value in NI children.