The role of esophageal pH-impedance testing in clinical practice

Parenteral Nutrition in Pediatric Patients with Neurodisability: Current Perspectives

Pediatric neurodisability describes functional limitations in children with varied severity and complexity often attributed to brain or neuromuscular abnormalities. The life expectancy of children with neurodisability is improving, but many will require significant medical support. The gastrointestinal tract is usually affected in children with neurodisability and can lead to a wide range of symptoms. In gastrointestinal (GI) dystonia, a newly coined term, feeding will trigger a distressing dystonia and symptoms can improve with cessation of feed. Parenteral nutrition (PN) is often viewed as a viable option in severe GI dystonia or when enteral feeding does not support sufficient nutrition. The use of PN in children with severe neurodisability is complex. It involves an intricate interplay between medical, psychological and ethical factors. In the absence of a universally agreed guidance on the use of PN in this cohort, paediatricians should maintain the individual need of the child at the centre of the decision-making process and work closely with families and other healthcare professionals before initiating or withholding PN in children with severe neurodisability. In this article, we discuss the complex and multifaceted approach to the use of PN in children with severe neurodisability and aimed to explore the medical, psychological and ethical aspect dilemmas facing clinicians looking after children with declining gut function who may require PN support.

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.

Advances in the diagnosis of GERD

Gastroesophageal reflux disease (GERD) is considered one of the most frequent chronic gastrointestinal diseases globally with high costs due to treatment and investigations.First line therapy is with proton pump inhibitors, those who do not respond to initial treatment usually require further investigations such as upper gastrointestinal endoscopy or ambulatory 24-hours esophageal pH monitoring. The total time of exposure to acid and the DeMeester score represent the most useful parameters associated with conventional pH-metry, because they can identify gastroesophageal reflux disease.Although pH-metry is considered the gold standard for the evaluation of gastroesophageal reflux disease, new impedance-based parameters have been introduced in recent years with the role of increasing the accuracy of diagnosing gastroesophageal reflux disease and characterizing the type of reflux. The development of multichannel intraluminal pH-impedance has improved the ability to detect and quantify gastroesophageal reflux. New parameters such as post-reflux swallowing peristaltic wave (PSPW) index and the mean nocturnal basal impedance (MNBI) have recently been introduced to assess GERD phenotypes more accurately. This review evaluates current GERD diagnotic tools while also taking a brief look at newer diagnostic parameters like PSPW and MNBI.

A novel ex vivo porcine model of acid-induced esophageal damage for preliminary functional evaluations of anti-gastroesophageal reflux disease medical devices

Aim

The aim of the study was to set up a porcine ex vivo model of acid-induced damage and to evaluate its performance by means of multichannel intraluminal impedance and pH (MII-pH) live recording, histology, and Evans blue (EB) permeability assay.

Materials and Methods

Thirteen esophagi, collected at a slaughterhouse, were ablated of their sphincters, pinned upright on a support, and placed in a thermostatic hood at 37°C with two infusion tubes and an MII-pH probe inserted in the top end. Three esophagi (histology controls) were only left in the hood for 3.5 h before sampling, while the remaining organs underwent the experimental protocol including saline infusion and recovery recording, and acid solution infusion and recovery recording.

Results

MII-pH analysis highlighted a significantly stronger decrease during acid infusion when compared to saline, but a better post-infusion recovery for saline solution. At the end of the protocol, MII was still statistically lower than baseline. The acid-damaged esophagi significantly absorbed more EB dye, and histology revealed strong mucosal exfoliation.

Conclusion

The proposed model of esophageal acid damage seems to be repeatable, reliable, and achievable using organs collected at the slaughterhouse. MII recording proved to have good sensitivity in detecting mucosal alterations also in ex vivo trials.

The Relationship Between Gastroesophageal Reflux Disease and Laryngopharyngeal Reflux Based on pH Monitoring

OBJECTIVES

Many studies on the relationship between gastroesophageal reflux disease (GERD) and laryngopharyngeal reflux (LPR) were based on symptoms, but there are few research on it using reflux monitoring. This study was designed to investigate the relationship between GERD and LPR based on pH monitoring.

METHODS

All patients were scheduled for esophageal manometry and pH monitoring sequentially. They were stratified into 4 groups as no reflux disease, isolated GERD, isolated LPR (iLPR), and GERD combined with LPR (GERD&LPR) according to pH monitoring.

RESULTS

The incidence of LPR in GERD was 46.3%, while the probability of combining GERD in LPR was 52.7%. The reflux profile in the laryngopharynx showed a significant difference in the total reflux time (17.82 ± 18.4 vs 9.62 ± 9.58, P = .023) and the percentage of total reflux time (1.31% ± 1.37% vs 0.71% ± .0.73%, P = .023) between the GERD&LPR and iLPR groups.

CONCLUSION

Laryngopharyngeal reflux can be combined with GERD or it can exist as an independent diagnosis. In patients with GERD&LPR, the total reflux time and the percentage of reflux time in the laryngopharynx are higher than those in the iLPR group. Reflux episodes in the laryngopharynx of patients with GERD&LPR may be derived from GERD.

Esophageal physiology-an overview of esophageal disorders from a pathophysiological point of view

The esophagus serves the principal purpose of transporting food from the pharynx into the stomach. A complex interplay between nerves and muscle fibers ensures that swallowing takes place as a finely coordinated event. Esophageal function can be tested by a variety of methods, endoscopy, manometry, and reflux monitoring being some of the most important. Regarding pathophysiology, motor disorders, such as achalasia, often cause dysphagia and/or chest pain. Functional esophageal disorders are a heterogeneous group with hypersensitivity as a dominant pathophysiological factor. Gastroesophageal reflux disease often causes symptoms, such as heartburn and regurgitation, and a spectrum of disease, ranging from minimal mucosal damage visible only in the microscope to esophageal ulcers and strictures in the most severe cases. Eosinophilic esophagitis is an immune-mediated condition that can result in significant dysphagia and associated luminal narrowing. In the following, we will provide an overview of the most common esophageal disorders from a combined pathophysiological and clinical view.

Impedance in the evaluation of the esophagus

The aim of this paper is to review esophageal electrical impedance technologies and to discuss the use of these technologies for physiological measurements, diagnostics, and therapy of esophageal disease. In order to develop a better understanding of the pathophysiology of and improve the diagnosis of esophageal disorders, such as gastroesophageal reflux disease (GERD) and achalasia, several new diagnostic tests, including intraluminal impedance, esophageal mucosal impedance, and the functional luminal imaging probe, have been developed. These technologies have proven valuable for assessment of the esophagus in recent years. They provide information on esophageal flow properties, mucosal integrity, lumen shape, and distensibility in esophageal disorders, in particular for GERD and achalasia. Despite their promise and novel clinical studies, the potential of these technologies has been far from realized. New multidisciplinary approaches will contribute to our understanding and interpretation of esophageal impedance data and disease mechanisms.