Indications, methodology, and interpretation of combined esophageal impedance-pH monitoring in children: ESPGHAN EURO-PIG standard protocol

Can MII-pH values predict the duration of treatment for GERD in preterm infants?

BACKGROUND

Little is known regarding the prognostic role of Multichannel Intraluminal Impedance and pH monitoring (MII/pH) parameters in preterm infants with Gastro-Esophageal Reflux Disease (GERD).

AIM

Our study aimed to evaluate the relationship between MII/pH variables and the duration of pharmacological therapy for GERD, in preterm infants with gestational age (GA) ≤34weeks.

SUBJECTS, STUDY DESIGN, OUTCOME MEASURES

We retrospectively reviewed data of all newborns with GA ≤34weeks that underwent MII/pH in our Neonatal Intensive Care Unit (NICU) and pharmacological treatment for GERD. We included them in a 12-month follow-up program. MII/pH parameters were used as independent variables and the duration of pharmacological therapy as dependent variable in linear regression models.

RESULTS

16 patients (GA 28.4±1.8weeks, BW 1122±427g) were enrolled into the study. Regression analysis performed on all reflux events reported a significant correlation between the duration of pharmacological treatment and MII-BEI (r(2)=0.36, p=0.01) and MII-reflux frequency (r(2)=0.33, p=0.02). Moreover, regression analysis performed on all events classified according to the corresponding pH change - acidic (ac.), weakly acidic (w.ac.) or weakly alkaline (w.a.) - showed a significant correlation between the duration of pharmacological treatment and MII-w.ac.BEI (r(2)=0.26, p=0.05), MII-w.ac. reflux frequency (r(2)=0.44, p=0.01), and MII-proximal w.ac. reflux frequency (r(2)=0.35, p=0.02). No statistically significant correlation was found between pH-Reflux Index and the duration of treatment.

CONCLUSION

The study shows how, in our population of preterm infants, MII-parameters could have not only a diagnostic role, but also a prognostic value in terms of the duration of pharmacological treatment.

Impedance Probe Testing Prior to Pediatric Airway Reconstruction

Objective:

This study aimed to determine if preoperative impedance testing changed management and if testing was associated with surgical outcome in patients undergoing airway reconstruction.

Methods:

Retrospective review of patients who had impedance testing prior to airway reconstruction at a tertiary pediatric hospital from January 2010 to September 2011. Charts were reviewed for demographics, medical/surgical history, impedance testing, and surgical outcomes.

Results:

Fifty-seven patients were included. Forty-seven (82%) were premature. Forty-seven (82%) had a primary diagnosis of subglottic stenosis. Twenty-six (45%) had prior airway surgery. Thirty-six (63%) had gastroesophageal reflux and 21 (36%) had undergone fundoplication. Patients without fundoplication had a median 46 total reflux, 7 proximal, and 14.5 acidic events compared to a median 5 total reflux, 0 proximal, and 0 acidic events in patients with fundoplication. Impedance testing changed management in 22% (8/36) of nonfundoplication patients and 9.5% (2/21) of fundoplication patients. In unadjusted analysis, fewer fundoplication patients had successful surgery compared to those without (33% vs 67%, P = .01). Prematurity, age at surgery, and previous airway surgery were also important predictors of surgical success.

Conclusion:

Fewer patients than anticipated had a change in management. Impedance testing was unlikely to change management in fundoplication patients. Patients with fundoplication were less likely to have a successful outcome, suggesting that factors other than reflux influence airway reconstruction outcomes.

Esophageal pH and Combined Impedance-pH Monitoring in Children

Esophageal pH monitoring is considered the gold standard for the diagnosis of gastroesophageal reflux disease because of the normal ranges across the pediatric age range. However, this method can only detect acid reflux. Multichannel intraluminal impedance-pH (MII-pH) monitoring has recently been used for the detection of bolus reflux in infants and children. This method allows for the detection of liquid, gas or mixed reflux in addition to acid, weakly acidic or weakly alkaline reflux. MII-pH monitoring can record the direction of flow and the height of reflux, which are useful parameters to identify an association between symptoms and reflux. However, the technique is limited by its high cost and the lack of normative data of MII-pH in the pediatric population. Despite certain limitations, MII-pH monitoring will become more common and gradually replace pH monitoring in the future, because pH monitoring is part of MII-pH.

Gastroesophageal reflux disease: exaggerations, evidence and clinical practice

OBJECTIVE

there are many questions and little evidence regarding the diagnosis and treatment of gastroesophageal reflux disease (GERD) in children. The association between GERD and cow's milk protein allergy (CMPA), overuse of abdominal ultrasonography for the diagnosis of GERD, and excessive pharmacological treatment, especially proton-pump inhibitors (PPIs) are some aspects that need clarification. This review aimed to establish the current scientific evidence for the diagnosis and treatment of GERD in children.

DATA SOURCE

a search was conducted in the MEDLINE, PubMed, LILACS, SciELO, and Cochrane Library electronic databases, using the following keywords: gastroesophageal reflux; gastroesophageal reflux disease; proton-pump inhibitors; and prokinetics; in different age groups of the pediatric age range; up to May of 2013.

DATA SYNTHESIS

abdominal ultrasonography should not be recommended to investigate gastroesophageal reflux (GER). Simultaneous treatment of GERD and CMPA often results in unnecessary use of medication or elimination diet. There is insufficient evidence for the prescription of prokinetics to all patients with GER/GERD. There is little evidence to support acid suppression in the first year of life, to treat nonspecific symptoms suggestive of GERD. Conservative treatment has many benefits and with low cost and no side-effects.

CONCLUSIONS

there have been few randomized controlled trials that assessed the management of GERD in children and no examination can be considered the gold standard for GERD diagnosis. For these reasons, there are exaggerations in the diagnosis and treatment of this disease, which need to be corrected.

Involvement of autonomic nervous activity changes in gastroesophageal reflux in neonates during sleep and wakefulness

BACKGROUND

It has been suggested that disturbed activity of the autonomic nervous system is one of the factors involved in gastroesophageal reflux (GER) in adults. We sought to establish whether transient ANS dysfunction (as assessed by heart rate variability) is associated with the occurrence of GER events in neonates during sleep and wakefulness.

METHODS

Nineteen neonates with suspected GER underwent simultaneous, synchronized 12-hour polysomnography and esophageal multichannel impedance-pH monitoring. We compared changes in HRV parameters during three types of periods (control and prior to and during reflux) with respect to the vigilance state.

RESULTS

The vigilance state influenced the distribution of GER events (P<0.001), with 53.4% observed during wakefulness, 37.6% observed during active sleep and only 9% observed during quiet sleep. A significant increase in the sympathovagal ratio (+32%, P=0.013) was observed in the period immediately prior to reflux (due to a 15% reduction in parasympathetic activity (P=0.017)), relative to the control period. This phenomenon was observed during both wakefulness and active sleep.

CONCLUSION

Our results showed that GER events were preceded by a vigilance-state-independent decrease in parasympathetic tone. This suggests that a pre-reflux change in ANS activity is one of the factors contributing to the mechanism of reflux in neonates.

Molecular diagnosis of eosinophilic esophagitis by gene expression profiling

BACKGROUND & AIMS

Gene expression profiling provides an opportunity for definitive diagnosis but has not yet been well applied to inflammatory diseases. Here we describe an approach for diagnosis of an emerging form of esophagitis, eosinophilic esophagitis (EoE), which is currently diagnosed by histology and clinical symptoms.

METHODS

We developed an EoE diagnostic panel (EDP) comprising a 96-gene quantitative polymerase chain reaction array and an associated dual-algorithm that uses cluster analysis and dimensionality reduction using a cohort of randomly selected esophageal biopsy samples from pediatric patients with EoE (n = 15) or without EoE (non-EoE controls, n = 14) and subsequently vetted the EDP using a separate cohort of 194 pediatric and adult patient samples derived from both fresh or formalin-fixed, paraffin-embedded tissue: active EoE (n = 91), control (non-EoE and EoE remission, n = 57), histologically ambiguous (n = 34), and reflux (n = 12) samples.

RESULTS

The EDP identified adult and pediatric patients with EoE with approximately 96% sensitivity and approximately 98% specificity, and distinguished patients with EoE in remission from controls, as well as identified patients exposed to swallowed glucorticoids. The EDP could be used with formalin-fixed, paraffin-embedded tissue RNA and distinguished patients with EoE from those with reflux esophagitis, identified by pH-impedance testing. Preliminary evidence showed that the EDP could identify patients likely to have disease relapse after treatment.

CONCLUSIONS

We developed a molecular diagnostic test (referred to as the EDP) that identifies patients with esophagitis in a fast, objective, and mechanistic manner, offering an opportunity to improve diagnosis and treatment, and a platform approach for other inflammatory diseases.

Gastroesophageal reflux in the 21st century

PURPOSE OF REVIEW

Gastroesophageal reflux (GER) remains a common, challenging problem for clinicians, with differentiation of normal development from disease a particular issue. This review updates clinicians on advances in diagnosis of GER, relationship to other problems, and current practice in management.

RECENT FINDINGS

Development and understanding of multichannel intraluminal impedance-pH monitoring has given insights into the relationship of GER to symptoms. Medical treatment has changed little. Avoidance of overmedicalizing normal development is the major issue for clinicians. Laparoscopic fundoplication is established as equivalent to open fundoplication. Newer endoscopic techniques have only limited use in children to date.

SUMMARY

Major changes in pediatric GER relate to understanding of physiology and relationship of GER to symptoms. The major challenge for clinicians involve differentiation of normal from abnormal GER, and applying the most relevant management.

Diagnosis of gastroesophageal reflux and anti-reflux procedures among Polish children with gastrostomies: a 10-year nationwide analysis

BACKGROUND/OBJECTIVES

To analyse the approach to diagnose gastroesophageal reflux (GER) and the qualification criteria for anti-reflux (AR) procedures in Polish children fed via gastrostomy between 2000 and 2010.

SUBJECTS/METHODS

An electronic questionnaire containing questions on the demographic and clinical data of patients with gastrostomies was distributed to six Polish centres of nutritional therapy. The portion pertaining to GER included data on clinical exponents, diagnostic procedures (pH-metry, pH-impedance, scintigraphy and upper gastrointestinal (GI) series) and AR.

RESULTS

In total, 348 children (M199/F149; age at gastrostomy 5.78±5.49 years) were included. Data on the diagnosis of GER and the AR criteria were available for 343 and 336 subjects, respectively. Percutaneous endoscopic gastrostomy was performed in 258/348 patients (74.1%), while surgery was performed in 80/348 patients (23%). The data from 10/348 (2.9%) cases were unavailable. At least one of the tests for GER was conducted in 177/343 (51.6%) of patients: pH-metry in 74/343 (21.6%), pH-impedance in 17/343 (5.0%), scintigraphy in 60/343 (17.5%) and upper GI series in 102/343 (29.7%). GER was reported in 114/343 cases (33.2%), and fundoplication was performed in 87 children (76.3% of patients with GER). The highest congruence between a positive test result and the decision to perform fundoplication was documented in cases of scintigraphy and upper GI series (P=0.00000 and P=0.00191, respectively). A significant increase in the prevalence of simultaneous gastrostomy and AR was observed over the decade analysed (r=0.8, P=0.009). This study revealed a centre-specific attitude towards the diagnosis of GER and the assessment of qualifications for fundoplication in Polish gastrostomy-fed children.

CONCLUSIONS

The unified diagnostic algorithm of GER and the universal qualification criteria for AR procedures need to be defined for gastrostomy-fed children.

The role of baseline impedance as a marker of mucosal integrity in children with gastro esophageal reflux disease

OBJECTIVES

Diagnosis of gastro esophageal reflux disease (GERD) in children is challenging. 24-h-pH-multichannel-intraluminal-impedance measurement (pH-MII) is the best diagnostic tool to display gastro esophageal reflux whereas esophageal endoscopy indicates mucosal lesions. The aim of this study was to compare esophageal endoscopy results with reflux parameters such as acid exposure time (reflux index RI), bolus exposure time (bolus index BI), baseline impedance level (BIL) detected by pH-MII in children with suspected GERD.

METHODS

Analysis of data from 285 children (38 infants) referred to our hospital with suspected GERD. Division into three 'reflux esophagitis' (RE)-stages depending on the severity of endoscopic and histological findings and comparison with reflux parameters in these stages. Further categorization into four groups based on the pH-MII-results.

RESULTS

Children with high-grade esophagitis had a significantly lower BIL; otherwise there was no significant association between elevated reflux parameters and esophagitis. Pathological pH-MII results (RI and BI) were associated with lower BIL in the distal impedance channel. The BIL was significantly lower in infants compared to children >1 year regardless of the RI or BI. The main difference between these groups regarding reflux parameters was a longer BI and a higher number of retrograde bolus movements.

CONCLUSION

Pathologic pH-MII results are not predictive for an erosive esophagitis and vice versa. Therefore, these two procedures cannot replace each other. A lower BIL is associated with esophagitis ≥ LA-grade B and may be caused by longer acid but also by longer bolus exposure and thus may be another useful parameter in GERD monitoring.

Challenges in the diagnosis of gastroesophageal reflux disease in infants and children

INTRODUCTION

The diagnosis of gastroesophageal reflux disease (GERD) is challenging. The wide variation in symptoms is a major reason for the controversies. Since the expression of GERD varies from nonerosive reflux disease over Barrett's esophagus to chronic respiratory disease, it is clear that not one investigation technique will provide an answer in all situations.

AREAS COVERED

Relevant literature published in PubMed and CINAHL and recent guidelines were collected and reviewed. Diagnostic tests were evaluated by the following criteria: ability to confirm a diagnosis, to exclude other diagnoses with similar presentation, to detect complications, to predict disease severity.

EXPERT OPINION

Multiple intraluminal impedance (MII) is extensively evaluated in recent years, but other new techniques and measurements were also developed, mainly to diagnose extra-esophageal symptoms. Although evidence for a "relation" between GER and extra-esophageal symptoms is demonstrated, the "causality" between both is not proven. MII measures in a reliable reproducible way non-acid or weakly acid reflux. However, as long as medical therapeutic options are limited to anti-acid medications, MII lacks therapeutic implications, and therefore clinical impact. Since investigations for GER are invasive or cause irradiation, normal ranges cannot be established. As a consequence, the "old" techniques remain the standard diagnostic tools: barium meal for anatomy, endoscopy for esophagitis, and pH monitoring to demonstrate a time relation between (acid) GER and symptoms. MII provides more information than pH monitoring, but is more expensive and has limited therapeutic impact as long as drugs are mainly "anti-acid."