Twenty-four-hour esophageal impedance-pH monitoring in healthy preterm neonates: rate and characteristics of acid, weakly acidic, and weakly alkaline gastroesophageal reflux

Evaluation of Gastroesophageal Reflux in Symptomatic Young Infants Using Multichannel Intraluminal pH-Impedance Testing: A large Cohort Study from a Single Center

OBJECTIVE

 This study aimed to assess the use of combined multichannel intraluminal impedance and pH studies (MII-pH) in a large group of symptomatic young infants, to characterize the occurrence of gastroesophageal reflux disease (GERD), and to establish temporal association of the reflux behaviors with gastroesophageal reflux using symptom indices.

STUDY DESIGN

 This is a retrospective cohort study on 181 infants who underwent MII-pH studies for clinical behaviors that were suggestive of GERD. Symptom index (SI) and symptom association probability (SAP) were used to establish symptom association with reflux. More than 100 GER episodes in 24 hours or acid reflux index > 10% was considered pathological reflux.

RESULTS

 A total of 181 infants (median age: 60 days, interquartile range [IQR]: 34-108) underwent MII-pH studies with median study duration of 22.41 hours (IQR: 21.5-23.32). A total of 4,070 hours of data were analyzed, with 8,480 reflux events (2,996 [35%] acidic, 5,484 [65%] nonacidic). A total of 2,541 symptoms were noted, 894 (35%) were temporally related to reflux events. A total of 113 infants (62.4%) had positive symptom association with SI > 50% and/or SAP > 95% for at least one symptom. There was modest symptom association for choking and gagging, but apnea, bradycardia, and desaturations had poor symptom association. Only 29 infants (16%) had pathological reflux, and only 18 infants (10%) had both pathological reflux and positive symptom association.

CONCLUSION

 MII-pH can be used to characterize GERD in young infants, along with establishing temporal association with symptoms. Pathological reflux in symptomatic young infants is not common, but symptom association may occur without frequent or acidic reflux.

KEY POINTS

· Gastroesophageal reflux (GER) disease can be studied in young infants using MII-pH, to characterize the frequency and nature of GER events.. · The probability of GER events being associated temporally with GER symptoms can also be determined using MII-pH in this population.. · Using frequency of GER events, reflux indices, and symptom association indices with MII-pH, infants having true GER disease can be identified, thereby reducing unnecessary therapy.. · Symptom association may occur even without frequent or severe acidic reflux..

Effect of different tube feeding methods on gastroesophageal reflux features in preterm infants: a pH-impedance monitoring study

A stepwise approach is currently considered the best choice to manage gastroesophageal reflux (GER) in preterm infants. This study aimed to evaluate the effect of different tube feeding techniques on GER frequency and features in symptomatic tube-fed preterm neonates. Tube-fed infants < 34 weeks' gestation were eligible for this prospective, bicentric, cross-over study if, due to GER symptoms, they underwent a diagnostic 24-h combined pH and multiple intraluminal impedance (pH-MII) monitoring. During the monitoring period, each infant received the same feeding cycle, repeated twice: continuous tube feeding, bolus feeding followed by tube feeding permanence and by tube feeding removal. The impact of these three feeding modalities on pH-MII GER features was assessed. Thirty-one infants were enrolled. Despite a low number of reflux episodes, a significant decrease in total GERs (P < 0.001), in GERs detected by pH monitoring (P < 0.001), and in both acid and non-acid GERs detected by MII (P < 0.001 and P = 0.009, respectively) was observed in association with continuous feeding compared to bolus feeds, followed or not by tube feeding removal. Compared to continuous feeding, both bolus feeding modalities were associated with a significantly higher number of proximal GERs (P < 0.001). No difference in any pH-MII parameter was observed in relation to tube feeding persistence after bolus feeding administration.

CONCLUSIONS

Continuous feeding and boluses may have a different impact on pH-MII GER features in symptomatic tube-fed preterm infants, whereas the permanence of the feeding tube across LES did not seem to worsen GER indexes.

WHAT IS KNOWN

• Due to the functional and anatomical immaturity of the gastrointestinal tract, gastroesophageal reflux (GER) is common in preterm infants. • A stepwise therapeutical approach which firstly undertakes conservative strategies is the most advisable choice to avoid potentially harmful pharmacological overtreatments in the preterm population.

WHAT IS NEW

• Continuous feeding and boluses may have a different impact on GER features assessed by pH-MII monitoring in tube-fed preterm infants. • The permanence of the feeding tube during or after the feeding period did not seem to worsen GER occurrence. • By reducing GER features, especially acid GER, continuous feeding may potentially contribute to limit the need for antiacid medications in this population.

Characterizing Biomarkers of Continuous Peristalsis and Bolus Transit During Oral Feeding in Infants at pH-Impedance Evaluation: Clinical and Research Implications

OBJECTIVE

To examine the biomarkers of pharyngoesophageal swallowing during oral feeding sessions in infants undergoing pH-impedance testing and determine whether swallow frequencies are distinct between oral-fed and partially oral-fed infants.

STUDY DESIGN

One oral feeding session was performed in 40 infants during pH-impedance studies and measurements included swallowing frequency, multiple swallow rate, air and liquid swallow rates, esophageal swallow clearance time, and gastroesophageal reflux (GER) characteristics. Linear and mixed statistical models were applied to examine the swallowing markers and outcomes.

RESULTS

Infants (30.2 ± 4.4 weeks' birth gestation) were evaluated at 41.2 ± 0.4 weeks' postmenstrual age. Overall, 10 675 swallows were analyzed during the oral feeding sessions (19.3 ± 5.4 minutes per infant) and GER events were noted (2.5 ± 0.3 per study). Twenty-four-hour acid reflux index (ARI) was 9.5 ± 2.0%. Differences were noted in oral-fed and partially oral-fed infants for volume consumption (P < .01), consumption rate (P < .01), and length of hospital stay in days (P < .01). Infants with ARI >7% had greater frequency of swallows (P = .01). The oral-fed group had greater ARI (12.7 ± 3.3%, P = .05).

CONCLUSIONS

Oropharyngeal swallowing regulatory characteristics decrease over the feeding duration and were different between ARI >7% vs ≤7%. Although GER is less in infants who are partially oral-fed, the neonates with increased acid exposure achieved greater oral intakes and shorter hospitalizations, despite the presence of comorbidities. Pharyngoesophageal stimulation as during consistent feeding or GER events can activate peristaltic responses and rhythms, which may be contributory to the findings.

Gastroesophageal reflux disease in preterm infants: unmet needs

INTRODUCTION

Many preterm present somatic symptoms including aerodigestive and cardiorespiratory manifestations, in combination with irritability and/or distress, which are often attributed to gastroesophageal reflux (GER), albeit for unclear reasons.

AREAS COVERED

We searched in PubMed, Google Scholar, and MEDLINE for guidelines, reviews, and randomized controlled trials up to March 2024.

EXPERT OPINION

The diagnosis of GER-disease (GERD) in preterm is challenging because manifestations are atypical and diagnostic investigations difficult and not devoid of risk for adverse events. In case of vomiting or regurgitation, GER as a consequence of anatomical or metabolic conditions should be considered. Although many preterm infants are treated with proton pump inhibitors, this is seldom needed. Low-quality evidence for alginates is available, but needs further evaluation. There is a need for an effective and safe prokinetic favoring esophageal clearance, increasing lower esophageal sphincter pressure and stimulating gastric emptying. Non-drug treatment such as feeding adaptations (volume, duration, and composition) and positional changes are insufficiently applied. Thickened formula is not indicated in preterm babies. In case none of the above recommendations did result in sufficient improvement, and if documentation of acid GER is not possible, a 2-4 week trial of a proton pump inhibitor is acceptable.

Comparison between Conventional and Simple Measuring Methods of Mean Nocturnal Baseline Impedance in Pediatric Gastroesophageal Reflux Disease

(1) Background: Multichannel intraluminal impedance-pH (MII-pH) monitoring is commonly used to diagnose gastroesophageal reflux disease (GERD). The mean nocturnal baseline impedance (MNBI) is an important parameter, reflecting the esophageal mucosal integrity and improvement in GERD. This study aims to evaluate the correlation between conventionally measured MNBI and a recently described simple MNBI measurement method in diagnosing pediatric GERD. (2) Methods: This prospective observational study enrolled 64 children aged one month to 18 years who underwent 24 h MII-pH monitoring. Conventional MNBI was measured during stable 10 min intervals at night, while the simple MNBI method averaged impedance throughout the nocturnal supine period. (3) Results: Strong correlations were found between conventional and simple MNBI values across all impedance channels in both infants (r > 0.85) and older children (r > 0.9). Conventional and simple MNBIs in the most distal channel (Z6) effectively differentiated non-erosive reflux disease (NERD) from other phenotypes, with AUCs of 0.864 and 0.860, respectively. The simple MNBI demonstrated good diagnostic performance with similar sensitivity and specificity to the conventional MNBI. (4) Conclusions: Including MNBI measurements into routine MII-pH monitoring may enhance GERD diagnosis and reduce the need for more invasive procedures.

24 h combined esophageal multichannel intraluminal impedance and pH monitoring in children with chronic cough

BACKGROUND

Chronic cough in children is closely related to gastroesophageal reflux (GER). However, this association has not been adequately studied due to a lack of diagnostic tools. Combined esophageal multichannel intraluminal impedance and pH (MII-pH) monitoring is considered the most accurate method for evaluating the association between symptoms and reflux, but data on its use in children with chronic cough are still lacking. We aimed to assess the association between chronic cough and GER in children through MII-pH monitoring.

METHODS

Children with chronic cough (> 4 weeks) who were suspected gastroesophageal reflux disease(GERD) were selected to undergo 24 h MII-pH monitoring at our hospital. Patients were divided into groups according to their age, body position, reflux index (RI) or total reflux events, and the differences between the groups were analyzed. Then the significance and value of 24 h pH and impedance monitoring in chronic cough and the relationship between chronic cough and reflux were discussed.

RESULTS

Overall, 426 patients were included. The median age was 12 months (interquartile range: 6-39.5 months), 129 (30.3%) patients had RI > 7% detected by pH-metry, and 290 (68.1%) patients had positive diagnosis based on the impedance data. GER predominantly occurred in the upright position and mostly involved weakly acidic reflux and mixed gas-liquid reflux. There were 14.1% of children in non-acid GER group were SAP positive showing no difference in acid GER group 13.2% (P = 0.88), whereas patients with SAP > 95% in MII positive group (47[16.2%]) is higher than in MII negative group (P < 0.05).

CONCLUSION

Twenty four hour MII-pH monitoring is safe, well tolerated in children, but also has a higher detection rate of gastroesophageal reflux. It can find identify weakly acidic reflux, weakly alkaline reflux and reflux events with different physical properties, which can explain the relationship between GER and chronic cough more comprehensively. It provides new approach for exploring the etiology, diagnosis and treatment of children with chronic cough.

Utility of the Post-Reflux Swallow-Induced Peristaltic Wave Index and Mean Nocturnal Baseline Impedance for the Diagnosis of Gastroesophageal Reflux Disease Phenotypes in Children

(1) Objectives: Assessment of novel impedance parameters such as the post-reflux swallow-induced peristaltic wave (PSPW) index and mean nocturnal baseline impedance (MNBI) have been proposed to enhance the accuracy of gastroesophageal reflux disease (GERD) diagnosis. We aimed to evaluate the clinical value of MNBI and the PSPW index in discerning different phenotypes of GERD in children. (2) Methods: We conducted a prospective, observational study that included 49 children aged 5-18 years, referred for MII-pH monitoring due to negative endoscopy and persisting gastroesophageal reflux symptoms despite acid-suppressant treatment. The PSPW index and MNBI were assessed along with conventional metrics. (3) Results: Using a receiver operating characteristic (ROC) curve analysis, MNBI (AUC 0.864) and the PSPW index (AUC 0.83) had very good performance in differentiating between non-erosive reflux disease (NERD) and functional phenotypes. The PSPW index (AUC 0.87) discriminated better between functional heartburn (FH) and reflux hypersensitivity (RH) compared to the MNBI (AUC 0.712). A PSPW cut-off value of 65% provided a sensitivity of 76.9% and a specificity of 90% in distinguishing FH and RH. The PSPW index (AUC 0.87) proved to have better performance than the MNBI (AUC 0.802) in differentiating between FH and non-FH patients. MNBI diagnosed FH with a sensitivity of 84% and a specificity of 80.6% at a cut-off value of 2563 Ω. (4) Conclusions: The PSPW index and MNBI are useful to distinguish between GERD phenotypes in pediatric patients.

Pathophysiology of gastro-oesophageal reflux disease: implications for diagnosis and management

Gastro-oesophageal reflux disease (GERD) is a common gastrointestinal disorder in which retrograde flow of gastric content into the oesophagus causes uncomfortable symptoms and/or complications. It has a multifactorial and partially understood pathophysiology. GERD starts in the stomach, where the refluxate material is produced. Following the trajectory of reflux, the failure of the antireflux barrier, primarily the lower oesophageal sphincter and the crural diaphragm, enables the refluxate to reach the oesophageal lumen, triggering oesophageal or extra-oesophageal symptoms. Reflux clearance mechanisms such as primary and secondary peristalsis and the arrival of bicarbonate-rich saliva are critical to prevent mucosal damage. Alterations of the oesophageal mucosal integrity, such as macroscopic oesophagitis or microscopic changes, determine the perception of symptoms. The intensity of the symptoms is affected by peripheral and central neural and psychological mechanisms. In this Review, we describe an updated understanding of the complex and multifactorial pathophysiology of GERD. It is now recognized that different GERD phenotypes have different degrees of reflux, severity of mucosal integrity damage and type, and severity of symptoms. These variations are probably due to the occurrence of a predominant pathophysiological mechanism in each patient. We also describe the main pathophysiological mechanisms of GERD and their implications for personalized diagnosis and management.

Proton pump inhibitor therapy may alter the sensory motor characteristics of pharyngoesophageal motility in infants with suspected GERD

BACKGROUND

Acid reflux index (ARI) is a biomarker for gastroesophageal reflux disease (GERD). The effects of short-term proton pump inhibitor (PPI) therapy on pharyngoesophageal motility and clearance mechanisms in infants remain unknown. We hypothesized that pharyngoesophageal reflexes and response to PPI are distinct between infants with 3%-7% and >7% ARI.

METHODS

Secondary analysis was performed from a subset of infants who participated in a randomized controlled trial (NCT: 02486263). Infants (N = 36, 29.9 ± 4.3 weeks gestation) underwent 4 weeks of PPI therapy, 1 week of washout, and longitudinal testing to assess: (a) clinical outcomes; (b) pH-impedance and symptom metrics including ARI, distal baseline impedance, clearance time, refluxate height, symptoms, I-GERQ-R scores, symptom association probability; (c) pharyngoesophageal motility reflexes and sensory motor characteristics. Comparisons were performed between infants with 3%-7% versus >7% ARI.

KEY RESULTS

From the 36 hospitalized infants treated: Pharyngoesophageal reflex latencies were prolonged (p > 0.05) and duration in ARI 3%-7% group only (p = 0.01); GER frequency, proximal ascent and clearance increased (ARI 3%-7%); weight gain velocity, oral feeding success, and fine motor score decreased while length of hospital stays increased in the ARI >7% group despite the decrease in symptoms and I-GERQ-R scores.

CONCLUSIONS & INFERENCES

Distinct changes in pharyngoesophageal sensory motor aspects of motility and reflex mechanisms exist after using PPI therapy in infants. Contributory factors may include the effects of maturation and aerodigestive comorbidities (GERD and BPD). Controlled studies incorporating placebo are needed to delineate the effects of PPI on causal and adaptive GERD mechanisms in infants with aerodigestive and feeding-related comorbidities.

Multichannel intraesophageal impedance with pH metry in Saudi children

BACKGROUND

Multichannel Intraesophageal Impedance with pH (MII-pH) provides complete characterization of gastroesophageal reflux (GER). The aim of this study was to report our experience in this relatively new technique, emphasizing the challenges in the performance and interpretation of the results.

METHODS

The study was conducted at King Khalid University Hospital at King Saud University in Riyadh. A retrospective review of the medical records of children who underwent MII-pH was performed. The procedure was performed and interpreted according to the recommended methodology. The impedance catheter was introduced nasally. The use of event markers and diary were explained to the accompanying person. At the end of the recording, the data were downloaded to the software analysis system.

RESULTS

MII-pH was performed on 98 children, and 16 studies were excluded from analysis for technical reasons. The median age was 32 (range 2-168) months and 44 (54%) were male. The prevalence of nonacid gastroesophageal reflux (NAGER), proximal extent of GER, and postprandial NAGER were 55%, 50%, and 70%, respectively. One hundred and fifty-three symptoms were reported during the study, but only two were significant.

CONCLUSION

The MII-pH was well-tolerated but the performance and interpretation were technically demanding. The main advantage was the detection of NAGER. However, the lack of normal values and the reliance on symptom association make the interpretation of the results challenging.

Comparison of direct effects of rice-thickened formula vs routine feeds on symptoms and gastroesophageal reflux indices: A crossover cohort study

BACKGROUND

We compared the direct effects of routine vs rice-thickened formula on 24-h pH-impedance and symptom characteristics and then examined if dietary effects were modified by acid reflux index severity in infants.

METHODS

Forty infants under consideration for gastroesophageal reflux disease and therapies were evaluated at 43 ± 1 weeks postmenstrual age. Each infant was equally fed routine diet and thickened formula during evaluations. Postprandial sessions were analyzed for acid reflux index, reflux events, clearance times, distal baseline impedance, and symptoms.

RESULTS

Thickened formula has no effect (P ≥ 0.05) on acid reflux events' characteristics or overall symptom frequency. However, refluxate height and frequency of weakly acidic events and cough were decreased (P < 0.05). Prolonged bolus clearance and a decrease in distal baseline impedance were noted with thickened feeds (vs routine feeds) when acid reflux index was >7 (P < 0.05).

CONCLUSION

Our pH-impedance testing protocol identifies direct effects of potential therapies at the point of care. Acutely, thickened formula does not impact acid-specific reflux indices but decreases full-column reflux and cough reflexes. In those with an acid reflux index of >7, thickened formula prolongs the distal esophageal bolus clearance (the mechanisms of which are uncertain). Clinical trials are needed to clarify objective indications and therapeutic use of thickened formulas for infants with gastroesophageal reflux disease, along with short- and long-term side effects.

Taking Care of Preterm Infants: Outpatient Considerations

In recent decades, the number of pre-term infants born each year has been on the rise as mortality rates decline with improvements in technology and medical care. As a result, many preterm infants are successfully discharged from the neonatal intensive care unit (NICU). However, with prematurity comes the increased risk of ongoing health and development needs. Special attention must be given to certain chronic conditions by the outpatient provider, including growth and nutrition; gastroesophageal reflux; immunizations; vision and hearing impairments; chronic lung diseases, including bronchopulmonary dysplasia and pulmonary hypertension; and neurodevelopmental outcomes. This article will detail some of these topics to better inform the primary care provider of appropriate strategies to manage these chronic conditions and sequalae on NICU discharge. [Pediatr Ann. 2023;52(6):e200-e205.].

The link between airway reflux and non-acid reflux in children: a review

OBJECTIVE

Airway reflux, a member of extra-esophageal reflux, has been linked to countless respiratory pathologies amongst children. The advent of novel instrumentation has enabled the discovery of non-acid reflux which was postulated as the main culprit of airway reflux. The objective of this review is to outline the association between non-acid reflux and airway reflux in children.

METHODS

A comprehensive review of recent literature on non-acid reflux and airway reflux in children was conducted. Studies ranged from January 2010 till November 2021 were searched over a period of a month: December 2021.

RESULTS

A total of eleven studies were identified. All studies included in this review revealed a strong link between non-acid reflux and airway reflux in children. 6 of the included studies are prospective studies, 3 retrospective studies, 1 cross-section study, and type of study was not mentioned in 1 study. The most common reported respiratory manifestation of non-acid reflux in children was chronic cough (7 studies). Predominant non-acid reflux was noted in 4 studies. The total number of children in each study ranges from 21 to 150 patients. MII-pH study was carried out in all studies included as a diagnostic tool for reflux investigation.

CONCLUSION

Non-acid reflux is the culprit behind airway reflux as well as other myriads of extra-esophageal manifestations in children. Multicentre international studies with a standardized protocol could improve scientific knowledge in managing non-acid reflux in airway reflux amongst children.

Oral Care Associated With Less Microaspiration in Ventilated Cardiac Patients

Aspiration is common in mechanically ventilated patients and may predispose patients to aspiration pneumonia, chemical pneumonitis, and chronic lung damage. Pepsin A is a specific marker of gastric fluid aspiration and is often detected in ventilated pediatric patients. We investigated the effect of oral care and throat suctioning in the detection of pepsin A in tracheal aspirates (TAs) up to 4 hours after these procedures.

Methods

Twelve pediatric patients between age 2 weeks to 14 years who underwent intubation for cardiac surgery were enrolled in this study. Six of the 12 patients were consented before their surgery with initial specimen collected at the time of intubation and last one shortly before extubation (intubation duration < 24 hours). The remaining 6 patients were consented after cardiac surgery. All specimens were collected per routine care per respiratory therapy protocol and shortly before extubation (intubation duration > 24 hours). Tracheal fluid aspirates were collected every 4 to 12 hours in the ventilated patients. Enzymatic assay for gastric pepsin A and protein determination were performed. The time of oral care and throat suctioning within 4 hours prior was recorded prospectively.

Results

A total of 342 TA specimens were obtained from the 12 intubated pediatric patients during their course of hospitalization; 287 (83.9%) showed detectable total pepsin (pepsin A and C) enzyme activity (> 6 ng/mL) and 176 (51.5%) samples had detectable pepsin A enzyme levels (>6 ng/mL of pepsin A). Only 29 samples of 76 samples (38.2%) had evidence of microaspiration after receiving oral care, while 147 of 266 (55.3%) samples were pepsin A positive when no oral care was provided. Odds ratio is 0.50 (Cl 0.30-0.84), and the number needed to treat is 5.8 (Confidence interval 3.4-22.3). Testing air filters for pepsin was not beneficial.

Conclusion

Oral care is a highly effective measure to prevent microaspiration of gastric fluid in ventilated pediatric patients. The number needed to treat (5.8) suggests this is a very effective prevention strategy. Our study suggests that pepsin A is a useful and sensitive biomarker that allows identification of gastric aspiration.

A quality improvement initiative to reduce acid-suppressing medication exposure in the NICU

BACKGROUND

Acid-suppressing medications (ASMs) are commonly prescribed in the neonatal intensive care unit (NICU), in particular among preterm infants, despite well-established adverse effects and little evidence to support efficacy.

LOCAL PROBLEM

We sought to develop an initiative to reduce ASM exposure in our predominantly inborn level III NICU. Our specific aim was to reduce the number of nonindicated ASM prescriptions by 50% within a 12-month period.

METHODS

Our multidisciplinary team developed an evidence-based guideline defining indications for ASM prescription in a level III NICU. Plan-do-study-act cycles included staff education, formal clinical practice guideline implementation, and implementation of standardized documentation tools in the electronic health record (EHR). Outcome measures were the number of nonindicated and total inpatient prescriptions started per month, duration of ASM prescription, and number of prescriptions continued after NICU discharge. Balancing measures were the number of patients started on thickened feeds and number of patients discharged home on nasogastric tube feeds. We used statistical process control and Pareto charts to assess these measures over a 12-month baseline period, 9-month implementation period, and 19-month post-implementation period spanning September 2017-December 2020.

RESULTS

Nonindicated ASM prescriptions decreased from median 3 to 0 per month from the baseline to post-implementation period. Simultaneously, the median number of ASM prescriptions at discharge declined from 2 to 0 per month. The median duration of inpatient prescriptions declined from 23 to 7 days. Rates of patients started on thickened feeds and patients discharged home on nasogastric tube feeds remained stable throughout the study.

CONCLUSION

Enactment of an evidence-based guideline was associated with a substantial decline in nonindicated ASM use in our NICU and a decline in duration of exposure to ASM's when prescribed. Our interventions proved effective in altering clinical practice and could be applied to other NICUs with similar patient populations aiming to reduce ASM use.

Pathophysiology of Pediatric Gastroesophageal Reflux Disease: Similarities and Differences With Adults

Gastroesophageal reflux (GOR) is defined as "the passage of gastric contents into the esophagus with or without regurgitation and vomiting" and gastroesophageal reflux disease (GORD) is defined "when GOR leads to troublesome symptoms affecting the daily functioning and/or complications." This definition was first developed in 2006 by the Montreal consensus group (1) and later on adopted by pediatric gastroenterology societies such as ESPGHAN and NASPGHAN in 2009 (2). The definition of gastroesophageal reflux reveals little about its pathophysiology and is focused on symptomatology. In this way, it acts as an umbrella term for the multifactorial causes of the disease and the various phenotypes encountered; from functional heartburn to hypersensitive esophagus and nonerosive reflux disease, to erosive esophagitis and Barrett's esophagus. This article is devoted to the pathophysiology of pediatric GORD in comparison to adult GORD and is divided in 2 parts. In the first part, we will systematically describe the different mechanisms for the generation and clearance of reflux events, while on the second part we will discuss the mechanisms involved in symptoms generation. Finally, we will discuss the similarities and differences between pediatric and adult GORD.

A Multichannel Intraluminal Impedance Gastroesophageal Reflux Characterization Algorithm Based On Sparse Representation

Gastroesophageal reflux disease (GERD) is a common digestive disorder with troublesome symptoms that has been affected millions of people worldwide. Multichannel Intraluminal Impedance-pH (MII-pH) monitoring is a recently developed technique, which is currently considered as the gold standard for the diagnosis of GERD. In this paper, we address the problem of characterizing gastroesophageal reflux events in MII signals. A GER detection algorithm has been developed based on the sparse representation of local segments. Two dictionaries are trained using the online dictionary learning approach from the distal impedance data of selected patches of GER and no specific patterns intervals. A classifier is then designed based on the l_p-norm of dictionary approximations. Next, a preliminary permutation mask is obtained from the classification results of patches, which is then used in post-processing procedure to investigate the exact timings of GERs at all impedance sites. Our algorithm was tested on 33 MII episodes, resulting a sensitivity of 96.97% and a positive predictive value of 94.12%.

Gastro-oesophageal reflux disease

Gastro-oesophageal reflux disease (GERD) is a common disorder in adults and children. The global prevalence of GERD is high and increasing. Non-erosive reflux disease is the most common phenotype of GERD. Heartburn and regurgitation are considered classic symptoms but GERD may present with various atypical and extra-oesophageal manifestations. The pathophysiology of GERD is multifactorial and different mechanisms may result in GERD symptoms, including gastric composition and motility, anti-reflux barrier, refluxate characteristics, clearance mechanisms, mucosal integrity and symptom perception. In clinical practice, the diagnosis of GERD is commonly established on the basis of response to anti-reflux treatment; however, a more accurate diagnosis requires testing that includes upper gastrointestinal tract endoscopy and reflux monitoring. New techniques and new reflux testing parameters help to better phenotype the condition. In children, the diagnosis of GERD is primarily based on history and physical examination and treatment vary with age. Treatment in adults includes a combination of lifestyle modifications with pharmacological, endoscopic or surgical intervention. In refractory GERD, optimization of proton-pump inhibitor treatment should be attempted before a series of diagnostic tests to assess the patient's phenotype.

Differentiating esophageal sensitivity phenotypes using pH-impedance in intensive care unit infants referred for gastroesophageal reflux symptoms

BACKGROUND

To identify esophageal sensitivity phenotypes relative to acid (S_Acid), bolus (S_Bolus), acid and bolus (S_Acid+Bolus), and none (S_None) exposures in infants suspected with gastroesophageal reflux disease (GERD).

METHODS

Symptomatic infants (N = 279) were evaluated for GERD at 42 (40-45) weeks postmenstrual age using 24-h pH-impedance. Symptom-associated probability (SAP) for acid and bolus components defined esophageal sensitivity: (1) S_Acid as SAP ≥ 95% for acid (pH < 4), (2) S_Bolus as SAP ≥ 95% for bolus, (3) S_Acid+Bolus as SAP ≥ 95% for acid and bolus, or (4) S_None as SAP < 95% for acid and bolus.

RESULTS

Esophageal sensitivity prevalence (S_Acid, S_Bolus, S_Acid+Bolus, S_None) was 28 (10%), 94 (34%), 65 (23%), and 92 (33%), respectively. Emesis occurred more in S_Bolus and S_Acid+Bolus vs S_None (p < 0.05). Magnitude (#/day) of cough and emesis events increased with S_Bolus and S_Acid+Bolus vs S_None (p < 0.05). S_Acid+Bolus had increased acid exposure vs S_None (p < 0.05). Distributions of feeding and breathing methods were distinct in infants with S_Bolus vs S_None (both, p < 0.05). Multivariate analysis revealed that arching and irritability events/day were lesser at higher PMAs (p < 0.001) and greater for infants on NCPAP (p < 0.01) with S_Bolus and S_Acid+Bolus (p < 0.05). Coughs/day was greater at higher PMAs (p < 0.001) for infants with gavage and transitional feeding methods (p < 0.02) with S_Bolus and S_Acid+Bolus (p < 0.05) but lesser with Trach (p < 0.001). Number of emesis events/day were greater with S_Bolus and S_Acid+Bolus (p < 0.001). Sneezes/day decreased for infants on Trach (p = 0.02).

CONCLUSIONS

Feeding and breathing methods can influence the frequency and type of aerodigestive symptoms. We differentiated esophageal sensitivity phenotypes in NICU infants referred for GERD symptoms using pH-impedance. Acid sensitivity alone was rare, which may explain poor response to acid suppressives; aerodigestive symptoms were predominantly linked with bolus spread. Magnitude of esophageal acid exposure and esophageal sensitivity to bolus spread may explain the pathophysiological basis for symptoms.

IMPACT

Objective GERD diagnosis and reasons for symptoms in NICU infants remains unclear. Differentiation of esophageal sensitivities by acid and bolus components of GER reveal distinct symptom profiles, specifically the bolus component of GER significantly contributes to symptom occurrence. Acid only sensitivity to GER is rare, and acid-suppressive therapy alone may not improve symptoms in a majority of NICU infants. Magnitude of esophageal acid exposure and esophageal sensitivity to any bolus spread may explain the pathophysiological basis for symptoms. Feeding and breathing methods can influence the frequency and type of aerodigestive symptoms. GERD treatments should be individualized to the patient's GERD phenotype and likely also target the bolus component of GER.

Role of feeding strategy bundle with acid-suppressive therapy in infants with esophageal acid reflux exposure: a randomized controlled trial

OBJECTIVE

To test the hypothesis that a feeding bundle concurrent with acid suppression is superior to acid suppression alone in improving gastroesophageal reflux disease (GERD) attributed-symptom scores and feeding outcomes in neonatal ICU infants.

METHODS

Infants (N = 76) between 34 and 60 weeks' postmenstrual age with acid reflux index > 3% were randomly allocated to study (acid-suppressive therapy + feeding bundle) or conventional (acid-suppressive therapy only) arms for 4 weeks. Feeding bundle included: total fluid volume < 140 mL/kg/day, fed over 30 min in right lateral position, and supine postprandial position. Primary outcome was independent oral feeding and/or ≥6-point decrease in symptom score (I-GERQ-R). Secondary outcomes included growth (weight, length, head circumference), length of hospital stay (LOHS, days), airway (oxygen at discharge), and developmental (Bayley scores) milestones.

RESULTS

Of 688 screened: 76 infants were randomized and used for the primary outcome as intent-to-treat, and secondary outcomes analyzed for 72 infants (N = 35 conventional, N = 37 study). For study vs. conventional groups, respectively: (a) 33% (95% CI, 19-49%) vs. 44% (95% CI, 28-62%), P = 0.28 achieved primary outcome success, and (b) secondary outcomes did not significantly differ (P > 0.05).

CONCLUSIONS

Feeding strategy modifications concurrent with acid suppression are not superior to PPI alone in improving GERD symptoms or discharge feeding, short-term and long-term outcomes.

IMPACT

Conservative feeding therapies are thought to modify GERD symptoms and its consequences. However, in this randomized controlled trial in convalescing neonatal ICU infants with GERD symptoms, when controlling for preterm or full-term birth and severity of esophageal acid reflux index, the effectiveness of acid suppression plus a feeding modification bundle (volume restriction, intra- and postprandial body positions, and prolonged feeding periods) vs. acid suppression alone, administered over a 4-week period was not superior in improving symptom scores or feeding outcomes. Restrictive feeding strategies are of no impact in modifying GERD symptoms or clinically meaningful outcomes. Further studies are needed to define true GERD and to identify effective therapies in modifying pathophysiology and outcomes. The improvement in symptoms and feeding outcomes over time irrespective of feeding modifications may suggest a maturational effect. This study justifies the use of placebo-controlled randomized clinical trial among NICU infants with objectively defined GERD.

Use of a non-invasive accelerometric method for diagnosing gastroesophageal reflux in premature infants

OBJECTIVE

To evaluate the clinical usefulness of a non-invasive accelerometric device to diagnose GER in preterm babies.

STUDY DESIGN

An accelerometer was taped over the sub-xiphoid process in 110 preterm (GA 29.6 ± 3.3 wk) infants (133 studies). Low frequency, sub-audible signals were captured via digital recording (sampling rate 200 Hz), then re-sampled (rate = 60 Hz) to create a spectrogram (focused range 0-30 Hz). Mean amplitude in the focused range was calculated.

RESULTS

Of 85 studies with simultaneous pH-metry and accelerometry, 18 had concurrent positive and 23 had concurrent negative scores, 42 had negative pH scores when accelerometry was positive (≥1 µV), consistent with non-acid reflux. Eleven infants at high risk of aspiration received surgical interventions. All but 1 had negative pH scores while 10/11 had positive accelerometry.

CONCLUSIONS

The non-invasiveness of this accelerometric technique allows for GER screening and for repeated testing to assess efficacy of interventions.

Response to therapy among neonates with gastro-esophageal reflux is associated with esophageal clearance

BACKGROUND

Few studies evaluated the efficacy of pharmacological therapy for gastro-esophageal reflux disease (GERD) in newborns, whose safety has been questioned. Esophageal basal impedance (BI) is a marker of mucosal integrity, and treatment with proton pump inhibitors significantly increases BI in infants; however, no correlation with clinical improvement was reported.

AIMS

To evaluate the relationship between BI and other esophageal pH-impedance parameters and clinical response to therapy in newborns with GERD.

STUDY DESIGN

Multicenter retrospective study.

SUBJECTS

Infants who received omeprazole or ranitidine for GERD.

OUTCOME MEASURES

Complete response to therapy was defined as symptom decrease by ≥50% compared to baseline, partial response as symptom decrease <50%, no response as no symptom decrease based on chart analysis. Response to therapy was assessed 2 and 4 weeks after the onset of therapy. Univariate and multivariate statistics were performed to assess associations between response to therapy and clinical/pH-impedance parameters.

RESULTS

We studied 60 infants (51 born preterm): 47 received omeprazole, 13 ranitidine. Response to therapy was associated with decreasing esophageal clearance time: odds ratio 0.308, 95%CI 0.126-0.753, p = 0.010 at 2 weeks, odds ratio 0.461, 95%CI 0.223-0.955, p = 0.037 at 4 weeks.

CONCLUSIONS

Clinical response to therapy among infants with GERD was associated with esophageal clearance but not with esophageal BI level.

Gastroesophageal Reflux Poses a Potential Risk for Late Complications of Bronchopulmonary Dysplasia: A Prospective Cohort Study

BACKGROUND

Bronchopulmonary dysplasia (BPD) is the most common respiratory disorder in extremely low birth weight infants. Although most symptoms of BPD improve, some late complications exist, even with regular treatment. Gastroesophageal reflux (GER), also common in extremely premature infants, may be related to many cardiorespiratory symptoms. However, the potential of GER as a risk factor for late complications associated with BPD is still unclear.

RESEARCH QUESTION

The goal of this study was to determine if GER increases the risk of late complications of BPD in infants.

STUDY DESIGN AND METHODS

A multicenter prospective cohort of 131 infants (79 male subjects, 52 female subjects) with BPD was enrolled. The development of late complications was assessed over an 18-month follow-up period. Twenty-four-hour pH-multichannel intraluminal impedance and gastric sodium concentrations were analyzed in all infants at 36 weeks' postmenstrual age and at the last interview. Prevalence and risk factors of late complications of BPD were analyzed by using forward logistic regression.

RESULTS

The prevalence of late complications in BPD infants was 63.79% and included respiratory symptoms (49.14%), vomiting (38.79%), retinopathy of prematurity (25.86%), hypoxic-ischemic injury (3.45%), rehospitalization (26.72%), and sudden death (0.86%). Respiratory diseases constituted the most frequent complication. The prevalence of GER in BPD was 42.24% and included acid GER (18.10%) and duodenogastroesophageal reflux (DGER; 24.14%). Risk factors for respiratory symptoms were gestational age ≤ 30 weeks (OR, 3.213; 95% CI, 1.221-8.460), birth weight < 1,500 g (OR, 2.803; 95% CI, 1.014-7.749), invasive ventilation > 7 days (OR, 4.952; 95% CI, 1.508-16.267), acid GER (OR, 4.630; 95% CI, 1.305-16.420), and DGER (OR, 5.588; 95% CI, 1.770-17.648). Infants with BPD and DGER were more prone to late complications than those with acid GER or no reflux.

INTERPRETATION

The prevalence of late complications is high in infants with BPD. GER (and in particular, DGER) poses a tentative risk for these late complications.

TRIAL REGISTRY

ClinicalTrials.gov; No.: NCT03014453; URL: www.clinicaltrials.gov.

Multichannel Intraluminal Impedance and pH Monitoring: A Step Towards Pediatric Reference Values

BACKGROUND/AIMS

Combined multichannel intraluminal impedance and pH monitoring (MII/pH) is considered the most accurate test to detect gastroesophageal reflux (GER), however lacking reference values. We aim to determine reference values for the pediatric population and to correlate these values with age and postprandial/fasting period.

METHODS

We evaluated MII/pH traces from patients (newborns, infants, and children) admitted to 3 Italian hospitals and who underwent MII/ pH for suspected GER disease. Patients with MII/pH traces that showed significant symptom-reflux associations and/or a pathological reflux index (> 6% for newborns and infants, > 3% for children) were excluded. Traces were analysed in their entirety, and in the postprandial period (first hour after a meal) and the fasting period (the following hours before the next meal) separately.

RESULTS

A total of 195 patients (46 newborns, 83 infants, and 66 children) were included. Age positively correlated with frequency of acidic GER events (r = 0.37, P < 0.05) and negatively associated with weakly acidic GER events (r = 0.46, P < 0.05).

CONCLUSIONS

This study describes the distribution of MII/pH values in a pediatric population with normally acidic GER exposure and no significant association between GER events and symptoms. These MII/pH values may be used as reference values in clinical practice for a corrected GER disease diagnosis in the pediatric population.

Prolonging gavage feeds for reduction of gastroesophageal reflux in infants

OBJECTIVE

To determine if prolonging gavage feedings in infants for ≥60 min is associated with decreased gastroesophageal reflux (GER) compared with bolus feeding using multiple-channel intraluminal impedance with pH probe (MII-pH).

STUDY DESIGN

Retrospective analysis of infants who underwent MII-pH between October 2009 and July 2018 and received gavage feedings. Infants were divided into two groups: bolus (<30 min) or prolonged (≥60 min). Symptoms, number of reflux events and percent time pH < 4 was compared.

RESULT

Fifty-eight infants underwent evaluation. Thirty-one (54%) received bolus gavage feedings and 27 (46%) received prolonged feedings. Groups differed in postmenstrual age. Total reflux episodes were significantly lower with prolonged feeding (median 19 vs. 28 episodes, p = 0.015), with no difference in acid exposure time. There was no significant difference in GER symptoms between the two groups.

CONCLUSION

Prolongation of gavage feedings was associated with decreased total numbers of GER events without reduction in GER symptoms.

The enigma of gastroesophageal reflux disease among convalescing infants in the NICU: It is time to rethink

Gastroesophageal reflux (GER) can be a normal physiological process, or can be bothersome, when aerodigestive consequences are associated; the latter is often interpreted as GER disease (GERD). However, the distinction between these two entities remains an enigma among infants surviving after neonatal intensive care (NICU) care. Symptoms related to GERD are heterogeneous, and are often managed with changes in diet, feeding methods, and acid suppressive therapy. However, none of these approaches have been well-tested in neonates; hence practice variation is very high world-wide. In this paper, we explain the variation in diagnosis, pathophysiology of the clinical presentation, and highlight approaches to diagnosis and management.

Assessment and Management of Gastroesophageal Reflux in The Newborn

Gastroesophageal reflux is the involuntary retrograde passage of gastric contents into the esophagus with or without regurgitation and is considered a normal physiologic process, occurring daily in greater than one-third of all infants. Gastroesophageal reflux disease (GERD) is pathologic reflux associated with poor weight gain, irritability, dysphagia and often requires evaluation and treatment. No gold-standard testing for GERD exists. Measurements made by pH probe or multichannel intraesophageal impedance may provide insight into the quantity and character of reflux. Those events do not correlate well with clinical symptoms. Most cases of GERD can be treated conservatively with alterations in the infant's environment and/or feeding pattern. Proton pump inhibitors remain the mainstay for pharmacotherapy of GERD, although these have been associated with increased rates of infection, especially in the preterm population. Neonatal GERD remains a difficult entity to define and manage, and additional studies to aid in the clinical diagnosis and management are needed. [Pediatr Ann. 2020;49(2):e77-e81.].

A New, Noninvasive Accelerometric Method for Diagnosing Acid andNon-Acid Gastroesophageal Reflux in Premature Infants: Proof of Concept

Non-acid reflux is common in premature neonates. Current methods of diagnosing gastroesophageal reflux (GER) such as pH probes, multichannel impedance monitoring, X-rays, or endoscopy are either invasive or unable to diagnose non-acid reflux. Passage of a naso-esophageal tube is uncomfortable. Imaging studies are of short duration and may miss reflux entirely. Herein, we present proof of concept of a noninvasive accelerometric device that detects acid and non-acid reflux in premature infants. An accelerometer was taped over the subxiphoid process in patients suspected of having GER who were already scheduled for pH probe or multichannel impedance monitoring. The largest cohort was preterm infants, but term infants and toddlers were also studied. Low-frequency subaudible signals were obtained on a digital recorder (sampling rate 200 Hz) signals. Fast Fourier transforms graphically displayed the frequency and amplitude of signals. Data were then resampled at a rate of 60 Hz to create a spectrogram with a focused range of 0-30 Hz representing reflux-associated events. Proof of concept was attained through successful comparison with results from concurrent pH probes, multichannel impedance recordings, and ultrasound studies. We have thus validated accelerometry as a noninvasive method for assessing both acid and non-acid GER. The noninvasiveness of this diagnostic modality allows for repeated testing to assess the efficacy of anti-reflux medications, even when patients remain on antacids. This technology allows for more rational management of patients with GER and represents a major advance in the diagnosis and treatment of GER.

Evaluation of Gastroesophageal Reflux in Children Born With Esophageal Atresia Using pH and Impedance Monitoring

OBJECTIVES

The aim of the study was to evaluate acid and nonacid gastroesophageal reflux in infants and school-aged children with esophageal atresia (EA) using pH-impedance (pH-MII) monitoring.

METHODS

Between 2012 and 2017, all 24-hour pH-MII studies performed in infants (≤18 months) and 8-year olds with EA were included. Antiacid therapy was discontinued before study. Exclusion criteria were: isolated tracheoesophageal fistula; esophageal replacement therapy; tube feeding; and monitoring <18 hours. Automatically detected retrograde bolus movements (RBM) were manually reviewed and modified/deleted if necessary.

RESULTS

We included 57 children (51% boys; 2% isolated EA; 44% thoracoscopic EA repair): 24 infants (median age 0.6 years) and 33 school-aged children (median age 8.2 years). Of the automatically detected 3313 RBM, 1292 were manually deleted from the tracings: 52% of nonacid RBM and 8% of acid RBM (mainly misinterpreted swallows or 1 event recognized as several events). In infants, median reflux index (RI; pH <4) was 2.6% (abnormal in n = 2), median RBM was 61 (62% nonacid, 58% mixed), and median of the mean BCT was 11 seconds. In older children, median RI was 0.3% (abnormal in n = 4), median RBM was 21 (64% nonacid; 75% mixed), and median of the mean BCT was 13 seconds.

CONCLUSIONS

Most children with EA off medication have a normal RI, yet experience a significant number of nonacid RBM. After manual revision of the tracings, a high percentage of RBM was deleted. Our data show that automated impedance analysis software needs refinement for use in infants and children with EA and question the need for standard antiacid therapy in these patients.

Liquid Gastroesophageal Reflux Characterization by Investigating Multichannel Intraluminal Impedance-pH Monitoring Data

Multichannel Intraluminal Impedance-pH (MII-pH) monitoring is designed to detect intraluminal bolus movement without the use of radiation and allows for detection of Gastroesophageal reflux (GER). Automatic analysis of MII-pH data are available however since the recordings are complex and filled with artifacts; a thorough and time-consuming review of the recordings, episode by episode, is still required. The proposed method was designed to segment GER events in a set of 100 episodes of two minutes interval of MII data based on a decision tree approach. An amount of 24 hours of MII-pH data belonging to eight patients were recorded, digitized and stored along with standardized timings of GER events that had been characterized by two gastroenterologist experts. The performance of the algorithm was evaluated using 100 individual GER events. The algorithm has been shown to perform correctly in over 95% of cases.

Correlation between cardiorespiratory events and gastro-esophageal reflux in preterm and term infants: Analysis of predisposing factors

BACKGROUND

The association between cardiorespiratory events (CRE) and gastro-esophageal reflux (GER) among neonates is still controversial.

AIMS

To test such an association in preterm and term infants.

STUDY DESIGN

Prospective observational study.

SUBJECTS

Forty-seven infants with suspected GER and recurrent CRE admitted at a neonatal intensive care unit, who underwent simultaneous and synchronized 24-hour recording of heart rate (HR), peripheral oxygen saturation (SpO2) and pH-impedance monitoring (MII-pH). HR/SpO2 data were filtered to avoid artefactual episodes of hypoxia and hypoperfusion.

OUTCOME MEASURES

The main outcome measure was the symptom association probability (SAP), with a 2-minute time window. Infants with positive (>95%) and negative (≤95%) SAP index tests were compared by univariate and multivariate statistics.

RESULTS

Median gestational age at birth was 294/7 weeks, median age at study 36 days. We recorded 3341 GER events and 4936 CRE (4710 desaturations, 226 bradycardias); 609/4936 (12%) CRE were temporally associated with GER episodes: 338 preceded and 271 followed GER events. The SAP index was significant in 5/47 (11%) patients. The SAP index including only CRE following GER events was significant in 3/47 (6%). There was no significant difference in the number of acid, weakly acid, non-acid, pH-only events preceding or following CRE between infants with SAP-positive and SAP-negative tests. Infants with positive SAP-index tests compared to those with SAP-negative tests had lower weight gain in the three days preceding the test and tended to have lower birth weight.

CONCLUSIONS

GER and CRE were associated in <11% of patients. The evaluation of ponderal growth might be helpful in predicting such an association.

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.

Oesophageal atresia

Oesophageal atresia (EA) is a congenital abnormality of the oesophagus that is caused by incomplete embryonic compartmentalization of the foregut. EA commonly occurs with a tracheo-oesophageal fistula (TEF). Associated birth defects or anomalies, such as VACTERL association, trisomy 18 or 21 and CHARGE syndrome, occur in the majority of patients born with EA. Although several studies have revealed signalling pathways and genes potentially involved in the development of EA, our understanding of the pathophysiology of EA lags behind the improvements in surgical and clinical care of patients born with this anomaly. EA is treated surgically to restore the oesophageal interruption and, if present, ligate and divide the TEF. Survival is now ~90% in those born with EA with severe associated anomalies and even higher in those born with EA alone. Despite these achievements, long-term gastrointestinal and respiratory complications and comorbidities in patients born with EA are common and lead to decreased quality of life. Oesophageal motility disorders are probably ubiquitous in patients after undergoing EA repair and often underlie these complications and comorbidities. The implementation of several new diagnostic and screening tools in clinical care, including high-resolution impedance manometry, pH-multichannel intraluminal impedance testing and disease-specific quality of life questionnaires now provide better insight into these problems and may contribute to better long-term outcomes in the future.

Gastroesophageal Reflux Disease in the Neonatal Intensive Care Unit Infant: Who Needs to Be Treated and What Approach Is Beneficial?

Gastroesophageal reflux (GER) and GER disease (GERD) pertaining to infants in the neonatal intensive care unit (NICU) are reviewed, based on research in this specific population. The developmental biology of the gastroesophageal junction, physiology of GER, and pathophysiology of GERD in this setting are summarized, and risk factors for GER and GERD identified. The epidemiology, economic burden, and controversies surrounding GERD in NICU infants are addressed, and an approach to GER and GERD in these patients formulated. Recent advancements in individual assessment of GER and GERD in the NICU infant are examined, and evidence-based guidelines for their adoption provided.

Mechanisms of Aerodigestive Symptoms in Infants with Varying Acid Reflux Index Determined by Esophageal Manometry

OBJECTIVE

To test whether symptom generation in infants is related to the severity of gastroesophageal reflux disease (GERD) symptoms as determined by the Acid Reflux Index (ARI), stimulus media, and stimulus volume during provocative esophageal manometry.

STUDY DESIGN

Symptomatic neonates (n = 74) born at a median of 28.9 weeks gestation (range, 23.4-39.4 weeks) were studied at a median of 41.0 weeks (range, 34.6-48.0 weeks) postmenstrual age using 24-hour pH-impedance methods to determine ARI severity, followed by provocative esophageal manometry with graded mid-esophageal infusions (0.1-5.0 mL) of air, water, and apple juice. Peristaltic reflexes and symptom characteristics were compared among ARI severity categories using linear mixed models and generalized estimating equations.

RESULTS

The effects of 2635 separate esophageal stimuli on reflexes and symptoms were analyzed. Peristaltic reflexes occurred in 1880 infusions (71%), and physical, cardiorespiratory, sensory symptoms were seen in 439 infusions (17%). Symptom prevalence did not differ across the ARI severity categories (ARI <3, 18%; ARI 3-7, 17%; ARI >7, 16%; P = 1.0). Symptom and peristaltic responses increased with incremental stimulus volumes (all media, P < .001).

CONCLUSIONS

Symptoms and peristaltic reflexes are manifestations of the recruitment of several neurosensory and neuromotor pathways evoked by mid-esophageal infusions. ARI severity grade plays no role in symptom generation, indicating that GERD should not be diagnosed and severity should not be assigned based on symptoms alone. An increase in symptom occurrence was noted with increasing stimulus volumes, which provided increased activation of receptors, afferents, and efferents in evoking peristaltic clearance reflexes.

Erythromycin and Reflux Events in Premature Neonates: A Randomized Clinical Trial

OBJECTIVE

Gastroesophageal reflux disease (GERD) in premature neonates may manifest as apnea, bradycardia, growth failure, aspiration, or feeding intolerance. Erythromycin ethylsuccinate (EES), is often used as a pro-kinetic in the management of GERD, despite lack of evidence or safety from randomized controlled trials. We sought to study the efficacy of enteral EES at a dose of 50 mg · kg · day in decreasing the frequency of gastroesophageal reflux events as determined by pH-multichannel intraluminal impedance (pH-MII) monitoring.

METHODS

In a randomized, double-blind, placebo-controlled trial, eligible premature neonates with clinical signs of GERD underwent 24-hour pH-MII monitoring. If >5 reflux events were identified on pH-MII, then subjects were randomized to receive either EES or placebo. Repeat 24-hour pH-MII was performed on day 7 of study treatment and compared to initial pH-MII.

RESULTS

Forty-three premature neonates were enrolled. Of those, 31 neonates were randomized, 15 to EES and 16 to placebo with a median (IQR) pretreatment total reflux events per 24 hours of 23 (16-40) and 29 (12-40), respectively. Day 7 total events per 24 hours decreased by 4 events in the EES group to 19 (15-33) and by 10 events in the placebo group to 19 (11-26) (P = 0.09). There were no differences in pretreatment and day 7 acidic and nonacidic reflux, proximal reflux, total or percent reflux time, median or longest bolus clearance time, or nurse-reported apnea events between groups.

CONCLUSIONS

Enteral EES did not decrease reflux events on 24-hour pH-MII at the dose studied. Therefore, it may be ineffective in the treatment of GERD in premature neonates.

Effects of Smoking Exposure in Infants on Gastroesophageal Reflux as a Function of the Sleep-Wakefulness State

OBJECTIVE

To determine whether perinatal smoking exposure is associated with gastroesophageal reflux (GER)-related changes in sleep-wakefulness states in neonates.

STUDY DESIGN

Thirty-one neonates, referred for the investigation of suspected GER, were recruited and underwent multichannel impedance-pH monitoring and synchronized 8- to 12-hour polysomnography. The infants' exposure to tobacco smoke was estimated by means of a urine cotinine assay. The total number, frequency (h^-1), and mean duration (minutes) of GER-pH (reflux events detected by the pH electrode only) and GER-imp (reflux events with bolus movement detected by impedance) events were determined. Intergroup differences (smoking-exposed group vs nonexposed group) were probed with nonparametric, unpaired Mann-Whitney U tests. A χ² test was used to assess a possible intergroup difference in bolus retrograde migration during GER-imp events.

RESULTS

According to the urine cotinine assay, 21 of the 31 neonates had been exposed to cigarette smoke during the perinatal period. The number (and frequency) of GER-imp was significantly greater (P = .016) in the exposed group (29 [0-90]) than in the nonexposed group (12 [2-35]). Migration of the esophageal bolus from the distal segment to the most proximal segment was significantly more frequent (P = .016) in the exposed group (83% of GER) than in the nonexposed group (41%). The GER pattern associated with smoking exposure was particularly obvious during Rapid eye movement sleep.

CONCLUSIONS

The more frequent occurrence and greater proximal migration of GER-imp in the smoking-exposed group (especially during rapid eye movement sleep) may have clinical relevance. Smoking exposure is a preventable risk factor for limiting the occurrence of GER in neonates.

Detection of gastro-oesophageal reflux in the neonatal unit

AIM

To determine whether a pH probe or multichannel intraluminal impedance (MII) more frequently detected gastro-oesophageal reflux and test the hypothesis that acid reflux was associated with lower baseline impedance.

METHODS

A prospective study of infants in whom reflux was suspected and evaluated using combined pH and multichannel impedance. Studies were considered abnormal if the acid index was >10% or there were >79MII reflux events in 24 hours. The acid index was the percentage of total study time with a pH

RESULTS

Forty-two infants [median gestational age 31 (range 23-42) weeks] were assessed. Only nine infants (21%) had abnormal studies, seven detected by pH monitoring, one by MII monitoring and one by both techniques (p = 0.04). After correcting for gestational age and post-natal age, baseline impedance remained negatively correlated with the acid index (r = -0.34, p = 0.038) and the maximum ACT (r = -0.44, p = 0.006).

CONCLUSION

Clinical suspicion of reflux was frequently incorrect, and reflux was more frequently detected by a pH probe. The inverse relationship of acid reflux to baseline impedance suggests that mucosal disruption may result from acid reflux in this population.

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Key Words

• Baseline oesophageal impedance
• Multichannel intraluminal impedance
• pH study

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MESH Headings Collapse

Grants

• National Institute for Health Research (NIHR) Biomedical Research Centre at Guy's and St Thomas' NHS Foundation Trust and King's College London

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Affiliation(s)

Thomas Rossor MRC Centre in Allergic Mechanisms of Asthma, King's College London, London, UK Department of Women and Children's Health, School of Life Course Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK
Ingran Lingam Neonatal Intensive Care Centre, King's College Hospital NHS Foundation Trust, London, UK
Abdel Douiri Department of Primary Care and Public Health Sciences, King's College London, London, UK NIHR Biomedical Research Centre, Guy's and St Thomas' NHS Foundation Trust, King's College London, London, UK
Ravindra Bhat Neonatal Intensive Care Centre, King's College Hospital NHS Foundation Trust, London, UK
Anne Greenough MRC Centre in Allergic Mechanisms of Asthma, King's College London, London, UK Department of Women and Children's Health, School of Life Course Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK NIHR Biomedical Research Centre, Guy's and St Thomas' NHS Foundation Trust, King's College London, London, UK

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Outcomes of laparoscopic nissen fundoplications in children younger than 2-years: single institution experience

BACKGROUND

Variation exists in the diagnostic testing for gastroesophageal reflux (GER) in infants and in the application of surgical therapy. There has been an increase in antireflux surgery (ARS) since the development of laparoscopy but the outcomes in high-risk infants is unclear. This study examines the results of laparoscopic fundoplication in infants less than 2 years.

METHODS

The results of infants less than 2 years undergoing laparoscopic Nissen fundoplication (Lap-F) from 2012 to 2015 were retrospectively reviewed and outcomes were followed until 2017.

RESULTS

There were 106 patients, median gestational age 32.50 weeks ± 6.35 SD and non-corrected age at operation 23.0 weeks ± 19.0 SD, mean weight of 4.81 kg ± 2.10 SD. One of the most common reasons for surgical consultation was improvement in respiratory status after insertion of nasoduodenal feeding tube. Of the Lap-F, 100 were with gastrostomy tube (GT). There were no conversions to open or intraoperative complications. The complication rate was 4.71%, and the reoperation rate was 5.66%, one fundoplication revision and the others gastrostomy revisions. The median time for feeds and to reach goal were 1 (1-14) and 4 (2-279) days, respectively. The 30-day mortality was 0.9% and long-term it was 4.71%. The long-term mortality was related to the underlying medical problems. The median follow-up was 113 (3-286) weeks. One patient required revision of the fundoplication and none required esophageal dilatation during the follow-up period.

CONCLUSION

Fundoplication is effective for relief of symptoms of GER in children younger than 2 years. The procedure has a low morbidity and mortality in this population.

Diagnosis and Management of Gastroesophageal Reflux in Preterm Infants

Gastroesophageal reflux (GER), generally defined as the passage of gastric contents into the esophagus, is an almost universal phenomenon in preterm infants. It is a common diagnosis in the NICU; however, there is large variation in its treatment across NICU sites. In this clinical report, the physiology, diagnosis, and symptomatology in preterm infants as well as currently used treatment strategies in the NICU are examined. Conservative measures to control reflux, such as left lateral body position, head elevation, and feeding regimen manipulation, have not been shown to reduce clinically assessed signs of GER in the preterm infant. In addition, preterm infants with clinically diagnosed GER are often treated with pharmacologic agents; however, a lack of evidence of efficacy together with emerging evidence of significant harm (particularly with gastric acid blockade) strongly suggest that these agents should be used sparingly, if at all, in preterm infants.

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.

Pediatric Gastroesophageal Reflux Clinical Practice Guidelines: Joint Recommendations of the North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition and the European Society for Pediatric Gastroenterology, Hepatology, and Nutrition

This document serves as an update of the North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition (NASPGHAN) and the European Society for Pediatric Gastroenterology, Hepatology, and Nutrition (ESPGHAN) 2009 clinical guidelines for the diagnosis and management of gastroesophageal reflux disease (GERD) in infants and children and is intended to be applied in daily practice and as a basis for clinical trials. Eight clinical questions addressing diagnostic, therapeutic and prognostic topics were formulated. A systematic literature search was performed from October 1, 2008 (if the question was addressed by 2009 guidelines) or from inception to June 1, 2015 using Embase, MEDLINE, the Cochrane Database of Systematic Reviews and the Cochrane Central Register of Controlled Clinical Trials. The approach of the Grading of Recommendations Assessment, Development and Evaluation (GRADE) was applied to define and prioritize outcomes. For therapeutic questions, the quality of evidence was also assessed using GRADE. Grading the quality of evidence for other questions was performed according to the Quality Assessment of Studies of Diagnostic Accuracy (QUADAS) and Quality in Prognostic Studies (QUIPS) tools. During a 3-day consensus meeting, all recommendations were discussed and finalized. In cases where no randomized controlled trials (RCT; therapeutic questions) or diagnostic accuracy studies were available to support the recommendations, expert opinion was used. The group members voted on each recommendation, using the nominal voting technique. With this approach, recommendations regarding evaluation and management of infants and children with GERD to standardize and improve quality of care were formulated. Additionally, 2 algorithms were developed, 1 for infants <12 months of age and the other for older infants and children.

Progression of Gastric Acid Production in Preterm Neonates: Utilization of In-vitro Method

Background: Limited studies are done regarding ability to produce gastric acid in preterm infants and most studies used in vivo method of assessing gastric pH. Objectives: To assess the feasibility of using an in vitro method of measuring gastric pH in babies ≤ 28 weeks gestational age (GA) and determine whether changes in gastric pH differ with gestational age, mode of delivery, and use of antenatal steroids. Design/Methods: Prospective study that enrolled extremely low birth weight (ELBW) babies. Gastric aspirate collected before feeding. In vitro testing of gastric aspirates for pH were done on days of life 1, 3, 5, 7, 14, and 28 by using pH electrode. The pH was measured on each sample in triplicate, mean calculated and used for data analysis. Stastical methods included descriptive statistics, t-tests and repeated measures ANOVA. Results: 29 subjects ≤ 28 weeks or birth weight ≤ 1,000 g were enrolled. No significant change was noted in pH measurements over time. Antenatal steroids and mode of delivery did not affect gastric acid pH. Conclusion: The in vitro method for gastric pH measurements is non-invasive and affords more frequent testing. It would be useful in studying various conditions that may affect gastric pH.

Gastro-Oesophageal Reflux and Apnoea: Is There a Temporal Relationship?

BACKGROUND

Gastro-oesophageal reflux (GOR) and apnoea are common in infants; whether there is a causal relationship is controversial.

OBJECTIVES

To determine whether there was a temporal relationship between GOR and apnoea, in particular, the frequency of obstructive apnoeas and if the frequency of GOR episodes correlated with apnoea frequency when maturity at testing was taken into account.

METHODS

Polysomnography and pH/multichannel intraluminal impedance (MII) studies were performed. Apnoeas were classified as central, obstructive, or mixed. MII events were classified as acidic (pH <4) or weakly acidic (4 < pH < 7). Apnoea frequency in the 5-min period after a reflux event was compared to that in the 5-min period preceding the event and that in a 5-min reflux-free period (control period).

RESULTS

Forty infants (median gestational age 29 [range 24-42] weeks) were assessed at a post-conceptional age of 37 (30-54) weeks. Obstructive (n = 580), central (n = 900), and mixed (n = 452) apnoeas were identified; 381 acid reflux events were detected by MII and 153 by the pH probe only. Apnoeas were not more frequent following GOR than during control periods. Both the frequency of apnoeas (p = 0.002) and GOR episodes (p = 0.01) were inversely related to post-conceptional age at testing, but were not significantly correlated with each other when controlled for post-conceptional age.

CONCLUSIONS

These results suggest that GOR does not cause apnoea.

How to Care for Patients with EA-TEF: The Known and the Unknown

PURPOSE OF REVIEW

Guidelines were recently published highlighting why esophageal atresia (EA) patients are prone to complication risks, and the need for long-term follow-up. In this review, we will focus on how to investigate and treat potential complications, as well as the pros and cons of different investigative and treatment modalities, and what areas continue to need further research.

RECENT FINDINGS

EA patients are at high risk for gastroesophageal reflux and esophageal strictures, and the sequela that result. Extraintestinal manifestations of gastroesophageal reflux disease (GERD) can appear similar to other pathologic diagnoses commonly found in EA patients, such as congenital stricture, eosinophilic esophagitis, esophageal dysmotility, tracheomalacia, recurrent fistula, aspiration, etc. Therefore, it is important to have a standardized way to monitor for these issues. pH impedance allows for detection of nonacid reflux and the height of reflux, which are important in correlating symptoms with reflux episodes. A multidisciplinary approach is beneficial in evaluating and monitoring EA patients in the long term.