Small volumes of feed can trigger transient lower esophageal sphincter relaxation and gastroesophageal reflux in the right lateral position in infants

[Expert consensus on enteral nutrition management for preterm infants in special situations (2024)]

Establishing enteral nutrition after the birth of preterm infants presents numerous challenges, particularly for those in special situations. Various disease factors and medical interventions impede the establishment of enteral feeding, leading to conflicts and controversies regarding feeding goals, feeding methods, and the challenges and solutions faced by these infants. A critical issue for clinical physicians is how to safely and promptly establish enteral nutrition to achieve full enteral feeding as quickly as possible. The consensus formulation working group, based on both domestic and overseas research, adopted the Grading of Recommendations Assessment, Development and Evaluation, and formed an expert consensus on enteral nutrition management for preterm infants in special situations. This consensus provides 14 recommendations for 9 common special situations, aiming to offer guidance on enteral nutrition management for preterm infants to improve their short and long-term outcomes. Citation:Chinese Journal of Contemporary Pediatrics, 2024, 26(7): 665-676.

Transition to a Safe Home Sleep Environment for the NICU Patient

Of the nearly 3.8 million infants born in the United States in 2018, 8.3% had low birth weight (<2500 g [5.5 lb]) and 10% were born preterm (gestational age of <37 completed weeks). Many of these infants and others with congenital anomalies, perinatally acquired infections, and other disease require admission to a NICU. In the past decade, admission rates to NICUs have been increasing; it is estimated that between 10% and 15% of infants will spend time in a NICU, representing approximately 500 000 neonates annually. Approximately 3600 infants die annually in the United States from sleep-related deaths, including sudden infant death syndrome International Classification of Diseases, 10th Revision (R95), ill-defined deaths (R99), and accidental suffocation and strangulation in bed (W75). Preterm and low birth weight infants are particularly vulnerable, with an incidence of death 2 to 3 times greater than healthy term infants. Thus, it is important for health care professionals to prepare families to maintain their infant in a safe sleep environment, as per the recommendations of the American Academy of Pediatrics. However, infants in the NICU setting commonly require care that is inconsistent with infant sleep safety recommendations. The conflicting needs of the NICU infant with the necessity to provide a safe sleep environment before hospital discharge can create confusion for providers and distress for families. This technical report is intended to assist in the establishment of appropriate NICU protocols to achieve a consistent approach to transitioning NICU infants to a safe sleep environment as soon as medically possible, well before hospital discharge.

The New Rome IV Criteria for Functional Gastrointestinal Disorders in Infants and Toddlers

Functional gastrointestinal disorders (FGIDs) are common worldwide and cover a wide range of disorders attributable to the gastrointestinal tract that cannot be explained by structural or biochemical abnormalities. The diagnosis of these disorders relies on the symptom-based Rome criteria. In 2016 the Rome criteria were revised for infants/toddlers and for children and adolescents. In this review, we discuss the novel Rome IV criteria for infants and toddlers. The criteria for infant colic were drastically changed, whereas only minor changes were made for regurgitation, cyclic vomiting syndrome, functional diarrhea, infant dyschezia and functional constipation. In addition to this, the new Rome IV discusses underlying mechanisms of pain in infants and toddlers, including the neuro-development of nociceptive and pain pathways, the various factors that are involved in pain experience, and methods of pain assessment in infants and toddlers is essential for the clinician who encounters functional pain in this age group. Overall, the Rome IV criteria have become more distinctive for all disorders in order to improve the process of diagnosing pediatric FGIDs.

Advances with Neonatal Aerodigestive Science in the Pursuit of Safe Swallowing in Infants: Invited Review

Feeding, swallowing, and airway protection are three distinct entities. Feeding involves a process of sequential, neurosensory, and neuromotor interactions of reflexes and behaviors facilitating ingestion. Swallowing involves anterograde bolus movement during oral-, pharyngeal-, and esophageal phases of peristalsis into stomach. During these events, coordination with airway protection is vital for homeostasis in clearing any material away from airway vicinity. Neurological-airway-digestive inter-relationships are critical to the continuum of successful feeding patterns during infancy, either in health or disease. Neonatal feeding difficulties encompass a heterogeneous group of neurological, pulmonary, and aerodigestive disorders that present with multiple signs posing as clinical conundrums. Significant research breakthroughs permitted understanding of vagal neural pathways and functional aerodigestive connectivity involved in regulating swallowing and aerodigestive functions either directly or indirectly by influencing the supra-nuclear regulatory centers and peripheral effector organs. These neurosensory and neuromotor pathways are influenced by pathologies during perinatal events, prematurity, inflammatory states, and coexisting medical and surgical conditions. Approaches to clarify pathophysiologic mapping of aerodigestive interactions, as well as translating these discoveries into the development of personalized and simplified feeding strategies to advance child health are discussed in this review article.

[Gastroesophageal reflux and sleep position of infants. A survey conducted in France by 493 pediatricians]

BACKGROUND AND AIMS

The supine sleeping position with the head higher than the legs has no impact on regurgitations in infants. Inclined ventral decubitus decreases regurgitations but is associated with an increased risk of sudden infant death syndrome (SIDS). The LUNE study aimed to evaluate the impact of regurgitations on the choice of sleeping position by pediatricians and parents.

METHODS

Cross-sectional case-control study (ratio 1:1) conducted in France in 2013. A representative sample of pediatricians recruited 3-week to 4-month-old breast- or formula-fed infants. Cases and controls were defined by the presence or absence of regurgitations. Collected data included Vandenplas codification for regurgitations (VD, range 0-6), associated symptoms, and variations in sleeping position since maternity hospital discharge.

RESULTS

A total of 1347 cases and 1346 controls were recruited by 493 pediatricians. Regurgitations were evaluated at VD1 (minor, 22 % of cases), VD2 (mild, 47 % of cases), or VD≥3 (moderate to severe, 31 % of cases). At the maternity hospital, the supine position was recommended to 96 % of parents for SIDS prevention. Since discharge, parents asked questions about the relationship between sleeping position and regurgitations (79 % of infants with GER versus 45 % of controls). The sleeping position was modified at least once since maternity discharge (42 % of infants with GER versus 35 % of controls). At inclusion, 86 % of infants with GER and 86 % of controls were sleeping on their back. Fifty-one percent of infants with GER and 28 % of controls slept in an inclined position. Pediatricians repeated the prescription of dorsal decubitus for 91 % of infants with GER and recommended an inclined position in 70 %.

CONCLUSIONS

Regurgitations had no impact on supine sleeping position. The inclined supine sleeping position was more frequent in infants with regurgitations with pediatricians' assent, which is not in agreement with evidence-based medicine.

Childhood Functional Gastrointestinal Disorders: Neonate/Toddler

In 2006, a consensus concerning functional gastrointestinal intestinal disorders (FGIDs) in infants and toddlers was described. At that time little evidence regarding epidemiology, pathophysiology, diagnostic work-up, treatment strategies and follow-up was available. Consequently the criteria for the clinical entities were more experience than evidence based. In the past decade, new insights have been gained in the different FGIDs in these age groups. Based on those, further revisions have been made to the criteria. The description of infant colic has been expanded to include criteria for the general pediatrician and specific criteria for researchers. The greatest change was the addition of a paragraph regarding the neurobiology of pain in infants and toddlers, including the understanding of the neurodevelopment of nociception and of the wide array of factors that may impact the pain experience.

Esophageal Bolus Transit in Newborns with Gastroesophageal Reflux Disease Symptoms: A Multichannel Intraluminal Impedance Study

PURPOSE

The aim of this study was to evaluate bolus transit during esophageal swallow (ES) and gastroesophageal reflux (GER) events and to investigate the relationship between the characteristics of ES and GER events in a population of term and preterm newborns with symptoms of gastroesophageal reflux disease (GERD).

METHODS

The study population consisted of term and preterm newborns referred to combined multichannel intraluminal impedance (MII) and pH monitoring for GERD symptoms. The frequency and characteristics of ES and GER events were assessed by two independent investigators. Statistical significance was set at p<0.05.

RESULTS

Fifty-four newborns (23 preterm) were included in the analyses. Median bolus head advancing time corrected for esophageal length (BHATc) was shorter during mealtime than during the postprandial period (median, interquartile range): 0.20 (0.15-0.29) s/cm vs. 0.47 (0.39-0.64) s/cm, p<0.001. Median bolus presence time (BPT) was prolonged during mealtime: 4.71(3.49-6.27) s vs. 2.66 (1.82-3.73) s, p<0.001. Higher BHATc (p=0.03) and prolonged BPT (p<0.001) were observed in preterm newborns during the postprandial period. A significant positive correlation between BHATc and bolus clearance time was also observed (ρ=0.33, p=0.016).

CONCLUSION

The analysis of ES and GER events at the same time by MII provides useful information to better understand the physiopathology of GERD. In particular, the analysis of BHATc during the postprandial period could help clinicians identify newborns with prolonged esophageal clearance time due to impaired esophageal motility, which could allow for more accurate recommendations regarding further tests and treatment.

Refluxo gastroesofágico e deglutição em recém nascidos e lactentes: revisão integrativa da literatura

Resumo: O refluxo gastroesofágico é encontrado em 25% dos bebês e pode acarretar vários prejuízos para o desenvolvimento. O objetivo deste trabalho foi realizar uma revisão integrativa da literatura buscando verificar se há publicações relacionando alterações da deglutição com o quadro de refluxo gastroesofágico em recém-nascidos e lactentes. A pesquisa foi realizada consultando os sites da Bireme e da PubMed. Os unitermos utilizados foram refluxo gastroesofágico, recém-nascido e lactente, em português e os correspondentes em inglês. Os descritores foram utilizados pareados, pois isolados abrangia muitos textos com temáticas diferentes da de interesse. Os trabalhos selecionados foram dos últimos dez anos. Não houve limite de tempo. De 1184 artigos da Bireme e 1600 da PubMed analisados a partir da aplicação dos critérios de inclusão e exclusão, restaram 23 artigos, sendo a maioria voltada aos sinais, sintomas e diagnóstico do RGE. Dois artigos abordaram o RGE e a deglutição, demonstrando que pode haver ou não relação entre RGE e disfagia orofaríngea em recém nascidos e lactentes, sendo que a escassez de pesquisas com essa temática demonstrou a necessidade de novos estudos abordando os aspectos patofisiológicos envolvidos.

Development of Suck and Swallow Mechanisms in Infants

Preterm infants' hospital discharge is often delayed due to their inability to feed by mouth safely and competently. No evidence-based supported guidelines are currently available for health-care professionals caring for these infants. Available interventions advocating benefits are not readily acknowledged for lack of rigorous documentation inasmuch as any improvements may ensue from infants' normal maturation. Through research, a growing understanding of the development of nutritive sucking skills has emerged, shedding light on how and why infants may encounter oral feeding difficulties due to the immaturity of specific physiologic functions. Unfortunately, this knowledge has yet to be translated to the clinical practice to improve the diagnoses of oral feeding problems through the development of relevant assessment tools and to enhance infants' oral feeding skills through the development of efficacious preventive and therapeutic interventions. This review focuses on the maturation of the various physiologic functions implicated in the transport of a bolus from the oral cavity to the stomach. Although infants' readiness for oral feeding is deemed attained when suck, swallow, and respiration are coordinated, we do not have a clear definition of what coordination implies. We have learned that each of these functions encompasses a number of elements that mature at different times and rates. Consequently, it would appear that the proper functioning of sucking, the swallow processing, and respiration need to occur at two levels: first, the elements within each function must reach an appropriate functional maturation that can work in synchrony with each other to generate an appropriate suck, swallow process, and respiration; and second, the elements of all these distinct functions, in turn, must be able to do the same at an integrative level to ensure the safe and efficient transport of a bolus from the mouth to the stomach.

Upper gastrointestinal motility: prenatal development and problems in infancy

Deglutition, or swallowing, refers to the process of propulsion of a food bolus from the mouth into the stomach and involves the highly coordinated interplay of swallowing and breathing. At 34 weeks gestational age most neonates are capable of successful oral feeding if born at this time; however, the maturation of respiration is still in progress at this stage. Infants can experience congenital and developmental pharyngeal and/or gastrointestinal motility disorders, which might manifest clinically as gastro-oesophageal reflux (GER) symptoms, feeding difficulties and/or refusal, choking episodes and airway changes secondary to micro or overt aspiration. These problems might lead to impaired nutritional intake and failure to thrive. These gastrointestinal motility disorders are mostly classified according to the phase of swallowing in which they occur, that is, the oral preparatory, oral, pharyngeal and oesophageal phases. GER is a common phenomenon in infancy and is referred to as GERD when it causes troublesome complications. GER is predominantly caused by transient relaxation of the lower oesophageal sphincter. In oesophageal atresia, oesophageal motility disorders develop in almost all patients after surgery; however, a congenital origin of disordered motility has also been proposed. This Review highlights the prenatal development of upper gastrointestinal motility and describes the most common motility disorders that occur in early infancy.

Body positioning and medical therapy for infantile gastroesophageal reflux symptoms

OBJECTIVE

Proton-pump inhibitors (PPIs) reduce acid gastroesophageal reflux (GER) and esophageal acid exposure in infants; however, they do not reduce total GER or symptoms attributed to GER. Reflux is reduced in the left lateral position (LLP). We hypothesize that the effect of LLP in combination with acid suppression is most effective in reducing GER symptoms in infants.

METHODS

In this prospective sham-controlled trial, infants (0-6 months) with symptoms suggestive of gastroesophageal reflux disease were studied using 8-hour pH-impedance, cardiorespiratory and video monitoring, direct nurse observation, and a validated questionnaire. Infants demonstrating a positive GER symptom association were randomized to 1 of 4 groups; PPI + LLP, PPI + head of cot elevation (HE), antacid (AA) + LLP, or AA + HE. HE and AA were considered "sham" therapies. After 2 weeks the 8-hour studies were repeated on-therapy.

RESULTS

Fifty-one patients were included (aged 13.6 [2-26] weeks). PPI + LLP was most effective in reducing GER episodes (69 [13] to 46 [10], P < 0.001) and esophageal acid exposure (median [interquartile range] 8.9% [3.1%-18.1%] to 1.1% [0%-4.4%], P = 0.02). No treatment group showed improvement in crying/irritability, although vomiting was reduced in AA + LLP (from 7 [2] to 2 [0] episodes P = 0.042). LLP compared with HE produced greater reduction in total GER (-21 [4] vs -10 [4], P = 0.056), regardless of acid-suppressive therapy. Acid exposure was reduced on PPI compared with AA (-6.8 [2.1] vs -0.9 [1.4]%, pH < 4, P = 0.043) regardless of positional intervention. A post-hoc analysis using automated analysis software revealed a significant reduction in crying symptoms in the PPI + LLP group (99 [65-103] to 62 [32-96] episodes, P = 0.018).

CONCLUSIONS

"Symptomatic gastroesophageal reflux disease" implies disease causation for distressing infant symptoms. In infants with symptoms attributed to GER, LLP produced a significant reduction in total GER, but did not result in a significant improvement in symptoms other than vomiting; however, automated analysis appeared to identify infants with GER-associated crying symptoms who responded to positioning therapy. This is an important new insight for future research.

Management of paediatric GERD

Paediatric GERD is complicated to manage, as symptoms are diverse and often difficult to interpret. In infants, regurgitation is a common physiological condition. Nevertheless, when it occurs frequently (>4 times per day) and causes the infant distress, parents often seek medical help. In children 2-10 years of age, GERD is often considered to cause extra-oesophageal symptoms, despite the absence of hard evidence. Diagnostic investigations often lack solid validation and the signs and symptoms of GERD overlap with those of cow's milk protein allergy and eosinophillic oesophagitis. Reassurance, dietary treatment and positional adaptations are recommended for troublesome infant reflux. Anti-acid medication, mainly PPIs, is over-used in infants even though, in many children, reflux is not an acid-related condition. Moreover, evidence is increasing that PPIs cause adverse events such as gastroenteritis and respiratory tract infections. Management in children older than 10 years is similar to that in adults. Using prokinetics to treat nonerosive reflux disease remains only a promising theoretical concept, as no such molecule is currently available. Today, the adverse effects of each prokinetic molecule largely outweigh its potential benefit. Laparoscopic surgery is indicated in children who have life-threatening symptoms or in cases of drug dependence.

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.

Pharmacological therapy of gastroesophageal reflux in preterm infants

Although gastroesophageal reflux (GER) is a very common phenomenon among preterm infants, its therapeutic management is still an issue of debate among neonatologists. A step-wise approach should be advisable, firstly promoting nonpharmacological interventions and limiting drugs to selected infants unresponsive to the conservative measures or who are suffering from severe GER with clinical complications. Despite of this, a concerning pharmacological overtreatment has been increasingly reported. Most of the antireflux drugs, however, have not been specifically assessed in preterm infants; moreover, serious adverse effects have been noticed in association to their administration. This review mainly aims to draw the state of the art regarding the pharmacological management of GER in preterm infants, analyzing the best piecies of evidence currently available on the most prescribed anti-reflux drugs. Although further trials are required, sodium alginate-based formulations might be considered promising; however, data regarding their safety are still limited. Few piecies of evidence on the efficacy of histamine-2 receptor blockers and proton pump inhibitors in preterm infants with GER are currently available. Nevertheless, a significantly increased risk of necrotizing enterocolitis and infections has been largely reported in association with their use, thereby leading to an unfavorable risk-benefit ratio. The efficacy of metoclopramide in GER's improvement still needs to be clarified. Other prokinetic agents, such as domperidone and erythromycin, have been reported to be ineffective, whereas cisapride has been withdrawn due to its remarkable cardiac adverse effects.

Effect of lateral positioning on gastroesophageal reflux (GER) and underlying mechanisms in GER disease (GERD) patients and healthy controls

BACKGROUND

Posture has been shown to influence the number of transient lower esophageal sphincter relaxation (TLESRs) and gastroesophageal reflux (GER), however, the physiology explaining the influence of right lateral position (RLP), and left lateral position (LLP) is not clear. The aim of this study was to determine the influence of RLP and LLP on TLESRs and GERD after a meal in GER disease (GERD) patients and healthy controls (HC) while monitoring gastric distension and emptying.

METHODS

Ten GERD patients and 10 HC were studied for 90 min (30 min test meal infusion, 30 min postprandial in either RLP or LLP (randomly assigned) and 30 min in alternate position). The study was repeated on a separate day in reverse position order. TLESRs, GER, and gastric emptying rate were recorded using manometry, multichannel intraluminal impedance, and (13) C-octanoate breath tests. Gastric distension was visualized by five serial gastric volume scintigraphy scans during the first 30 min.

KEY RESULTS

Gastroesophageal reflux, (GER) disease patients had increased numbers of TLESRs in RLP compared to LLP in the first postprandial hour [5 (4-14) and 4.5 (2-6), respectively, P = 0.046] whereas the number of TLESRs was not different in RLP and LLP [4 (2-4) and 4 (3-6), respectively, P = 0.7] in HC. Numbers of GER increased similar to TLESRs in GERD patients. In GERD patients, gastric emptying reached peak (13)CO(2) excretion faster and proximal gastric distension was more pronounced.

CONCLUSIONS & INFERENCES

In GERD patients, TLESRs, GER, distension of proximal stomach, and gastric emptying are increased in RLP compared to LLP. This effect is not seen in HC.

Pathophysiology of aerodigestive pulmonary disorders in the neonate

No test can provide a definitive diagnosis of aerodigestive disease. When interpreting tests, one should weigh the benefits and weaknesses of different technologies and methods, scientific appropriateness of the testing conditions, clinicopathologic correlation, and pharmacologic approaches. Gastroesophageal reflux disease (GERD) symptoms and airway symptoms can coexist, and they cannot be distinguished without specific testing and direct observations. Important aerodigestive disorders include dysphagia, GERD, and aggravation of airway injury due to malfunctions of swallowing or airway protection mechanisms. Objective evaluation of aerodigestive reflexes and symptom correlation may provide support for evidence-based personalized management of feeding and airway protection strategies.

Different in vitro and in vivo profiles of substituted 3-aminopropylphosphinate and 3-aminopropyl(methyl)phosphinate GABA(B) receptor agonists as inhibitors of transient lower oesophageal sphincter relaxation

BACKGROUND AND PURPOSE

Gastro-oesophageal reflux is predominantly caused by transient lower oesophageal sphincter relaxation (TLOSR) and GABA(B) receptor stimulation inhibits TLOSR. Lesogaberan produces fewer CNS side effects than baclofen, which has been attributed to its affinity for the GABA transporter (GAT), the action of which limits stimulation of central GABA(B) receptors. To understand the structure-activity relationship for analogues of lesogaberan (3-aminopropylphosphinic acids), and corresponding 3-aminopropyl(methyl)phosphinic acids, we have compared representatives of these classes in different in vitro and in vivo models.

EXPERIMENTAL APPROACH

The compounds were characterized in terms of GABA(B) agonism in vitro. Binding to GATs and cellular uptake was done using rat brain membranes and slices respectively. TLOSR was measured in dogs, and CNS side effects were evaluated as hypothermia in mice and rats.

KEY RESULTS

3-Aminopropylphosphinic acids inhibited TLOSR with a superior therapeutic index compared to 3-aminopropyl(methyl)phosphinic acids. This difference was most likely due to differential GAT-mediated uptake into brain cells of the former but not latter. In agreement, 3-aminopropyl(methyl)phosphinic acids were much more potent in producing hypothermia in rats even when administered i.c.v.

CONCLUSIONS AND IMPLICATIONS

An enhanced therapeutic window for 3-aminopropylphosphinic acids compared with 3-aminopropyl(methyl)phosphinic acids with respect to inhibition of TLOSR was observed and is probably mechanistically linked to neural cell uptake of the former but not latter group of compounds. These findings offer a platform for discovery of new GABA(B) receptor agonists for the treatment of reflux disease and other conditions where selective peripheral GABA(B) receptor agonism may afford therapeutic effects.

Localization of mGluR5, GABAB, GABAA, and cannabinoid receptors on the vago-vagal reflex pathway responsible for transient lower esophageal sphincter relaxation in humans: an immunohistochemical study

BACKGROUND

  Transient lower esophageal sphincter relaxations (TLESRs) are the predominant mechanisms underlying gastro-esophageal reflux. TLESRs are mediated by a vago-vagal reflex, which can be blocked by interaction with metabotropic Glutamate Receptor 5 (mGluR5), γ-aminobutyric acid type B (GABA(B)), γ-aminobutyric acid type A (GABA(A)), and cannabinoid (CB) receptors. However, the distribution of these receptors in the neural pathway underlying the triggering of TLESRs has not been evaluated in humans.

METHODS

  Using immunohistochemistry, we investigated the distribution of mGluR5, GABA(A), GABA(B), CB1, and CB2 receptors in the human nodose ganglion, the brain stem, and the myenteric plexus of the esophagus.

KEY RESULTS

  MGluR5, GABA(B), CB1, and CB2 receptors are abundantly expressed in neurons of the myenteric plexus of the LES, nodose ganglion cell bodies and nerve fibers, the dorsal motor nucleus, and nucleus of the solitary tract in the brain stem. GABA(A) receptors are expressed in the same regions except in the nodose ganglion and myenteric plexus of the LES.

CONCLUSIONS & INFERENCES

  Human mGluR5, GABA(A,B), and CB(1,2) receptors are abundantly expressed along the vago-vagal neural pathway and involved in the triggering of TLESRs. These findings are not only in line with the central side effects observed during treatment with reflux inhibitors such as GABA(B) receptor agonists and mGluR5 antagonists, but also suggest that peripherally acting compounds may be effective.