Manometric evaluation of esophageal-protective reflexes in infants and children

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.

A decade of evidence: standardized feeding initiative targeting feeding milestones and predicting NICU stays in premature infants in an all-referral level IV NICU

OBJECTIVE

Ten-year data from the simplified, individualized, milestone-targeted, pragmatic, longitudinal and educational (SIMPLE) feeding initiative were examined by gestational age (GA) category to characterize the feeding milestones, length of hospital stays (LOHS), annual variability and predictive models for LOHS.

STUDY DESIGN

Preterm infants (≤32 weeks GA, N = 434) in level-IV NICU had milestone-targeted feeding plans. Continuous data were analyzed for outcomes.

RESULTS

Over 93% successfully attained full oral feedings. Earlier acquisition of feeding milestones correlated with earlier discharge (P < 0.05). Year-wise analysis showed sustained maintenance of milestones (P < 0.05). Milestones and outcomes (P < 0.001) were significantly correlated with different GA categories. Prediction models for LOHS were derived using GA, BPD, age at full enteral, postmenstrual age (PMA) at 1st and full oral feeds.

CONCLUSIONS

The SIMPLE feeding program minimized variability and promoted acquisition of feeding milestones consistently. LOHS is predictable using feeding milestones, co-morbidities, GA, and PMA at feeding milestones.

Evidence-Based Approaches to Successful Oral Feeding in Infants with Feeding Difficulties

Infants in the neonatal intensive care unit (NICU) frequently have feeding difficulties with the root cause remaining elusive to identify. Evaluation of the provider/parent/infant feeding process may provide objective clues to sources of feeding difficulty. Specialized testing may be necessary to determine if the infant's swallowing skills are dysfunctional, immature, or maldeveloped, and to determine the risk of feeding failure or chronic tube feeding. Current evidence-based diagnostic and management approaches resulting in successful oral feeding in the NICU infant are discussed.

Pharyngoesophageal motility reflex mechanisms in the human neonate: importance of integrative cross-systems physiology

Swallowing is a critical function for survival and development in human neonates and requires cross-system coordination between neurological, airway, and digestive motility systems. Development of pharyngoesophageal motility is influenced by intra- and extrauterine development, pregnancy complications, and neonatal comorbidities. The primary role of these motility reflex mechanisms is to maintain aerodigestive homeostasis under basal and adaptive biological conditions including oral feeding, gastroesophageal reflux, and sleep. Failure may result in feeding difficulties, airway compromise, dysphagia, aspiration syndromes, and chronic eating difficulties requiring prolonged tube feeding. We review the integration of cross-systems physiology to describe the basis for physiological and pathophysiological neonatal aerodigestive functions.

Characterization of Esophageal and Sphincter Reflexes across Maturation in Dysphagic Infants with Oral Feeding Success vs Infants requiring Gastrostomy

To test the hypothesis that esophageal and sphincteric sensory-motor reflexes are distinct across maturation in infants with dysphagia receiving gastrostomy-tube (G-tube). This is a retrospective review of 29 dysphagic infants (N = 15 study requiring gastrostomy, N = 14 age matched control achieving oral feeds) that underwent longitudinal pharyngeal-esophageal manometry at 42.3 (37-50.2) weeks postmenstrual age (PMA) and 48.9 (43.3-57.9) weeks PMA. Graded stimuli (0.1-5 mL) of varying media (air, water, and apple juice) tested esophageal peristaltic reflex, upper esophageal sphincter contractile reflex (UESCR), and lower esophageal sphincter relaxation reflex (LESRR). Comparisons were performed between study and controls and across maturation (time-1 vs time-2). Data represented as mean ± SE or OR (95% CI). Across maturation (time-1 vs time-2): Study infants did not exhibit significant differences across in peristaltic, UES, or LES reflexes (all p > 0.05). In contrast, controls exhibited increased UES resting pressure (13 ± 3 vs 17 ± 3 mmHg, p = 0.001), LES resting pressure (22 ± 3 vs 25 ± 3 mmHg, p < 0.009), LES nadir pressure (0.5 ± 1 vs 4.3 ± 1 mmHg, p = 0.001), and esophago-deglutition responses [2.5 (1.23-4.88), p = 0.04], and decreased secondary peristalsis [0.44 (0.31-0.61), p = 0.001], UESCR [0.4 (0.25-0.65), p = 0.001], LESRR [0.4 (0.24-0.75), p = 0.01], and symptoms [0.6 (0.45-0.83), p = 0.005]. Among infants with dysphagia, esophageal provocation induced peristaltic reflex, UESCR, and LESRR advance with longitudinal maturation when infants are oral-fed successfully, but not in those who received gastrostomy. Underlying mechanisms may be related to esophageal sensitivity, afferent or efferent transmission, and coordination of upstream excitation and downstream inhibition, which can be potential therapeutic targets for improving feeding capabilities after gastrostomy placement in infants with dysphagia.

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.

Impact of Feeding Strategies With Acid Suppression on Esophageal Reflexes in Human Neonates With Gastroesophageal Reflux Disease: A Single-Blinded Randomized Clinical Trial

INTRODUCTION

Aims were to test hypothesis that esophageal provocation-induced reflexes are superior with acid suppression plus feeding modifications vs acid suppression alone among infants treated for gastroesophageal reflux disease (GERD).

METHODS

Infants (N = 49, 41.3 ± 2.6 of postmenstrual age) with acid reflux index >3% underwent longitudinal motility testing (weeks 0 and 5) with graded midesophageal provocation to test randomly allocated therapies (4 weeks' proton pump inhibitor [PPI] ± feeding modifications) on sensory-motor aerodigestive reflexes. Feeding modification included restricted fluid volume <140 mL/kg per day, fed over 30 minutes in right lateral position and supine postprandial position. Primary motility outcome was frequency-occurrence of peristaltic reflex. Secondary outcomes included upper esophageal sphincter contractile reflex, lower esophageal sphincter (LES) relaxation reflex, respiratory change, and symptom characteristics.

RESULTS

Treatment groups did not differ for primary outcome (odds ratio = 0.8, 95% confidence interval 0.4-1.6, P = 0.99) or secondary outcomes (all P > 0.05). For both treatment groups at follow-up, distal esophageal contraction and LES tone decreased, and LES relaxation reflex occurrence is less frequent (all P < 0.05). In a subgroup analysis, comparing infants with PPI washout (N = 40) vs with continued (N = 9) PPI therapy, no differences were noted for aerodigestive reflex response frequency-occurrence (all P > 0.05).

DISCUSSION

In infants with GERD, feeding modification with acid suppression is not superior to acid suppression alone in modifying aerodigestive reflexes (frequency, sensation, or magnitude). Contiguous areas targeted by GER, i.e., LES and distal esophageal functions, worsened at follow-up for both groups despite PPI therapy. Maturation is likely the key factor for GERD resolution in infants, justifying the use of placebo in clinical trials for objectively determined GERD.

Gastroesophageal Reflux Disease in the Neonatal Intensive Care Unit Neonate: Controversies, Current Understanding, and Future Directions

Gastroesophageal reflux (GER) is considered physiologic and is a normal process; whereas, when aerodigestive consequences are associated, it is often interpreted as GER disease (GERD). However, the distinction between them remains a challenge in infants in the NICU. Reflux-type of symptoms are heterogeneous, and often managed with changes in diet, feeding methods, and acid-suppressive therapy; all these empiric therapies lack objectivity; hence, practice variation is universal. We clarify the current controversies, explain the potential role of GERD in causing symptoms and complications, and highlight current advances. The evidence basis for the diagnostic strategies is discussed.

Maturation Modulates Pharyngeal-Stimulus Provoked Pharyngeal and Respiratory Rhythms in Human Infants

Pharyngeal-provocation induced aerodigestive symptoms in infants remain an enigma. Sources of pharyngeal provocation can be anterograde as with feeding, and retrograde as in gastroesophageal reflux. We determined maturational and dose-response effects of targeted pharyngeal-stimulus on frequency, stability, and magnitude of pharyngeal and respiratory waveforms during multiple pharyngeal swallowing responses in preterm-born infants when they were of full-term postmenstrual age (PMA). Eighteen infants (11 male) were studied longitudinally at 39.8 ± 4.8 weeks PMA (time-1) and 44.1 ± 5.8 weeks PMA (time-2). Infants underwent concurrent pharyngo-esophageal manometry, respiratory inductance plethysmography, and nasal airflow thermistor methods to test sensory-motor interactions between the pharynx, esophagus, and airway. Linear mixed models were used and data presented as mean ± SEM or %. Overall, responses to 250 stimuli were analyzed. Of the multiple pharyngeal swallowing responses (n = 160), with maturation (a) deglutition apnea duration decreases (p < 0.01), (b) number of pharyngeal waveform peaks and duration decreases for initial responses (p < 0.01), and subsequent responses have lesser variation and greater stability (p < 0.01). With increment in stimulus volumes we noted (a) increased prevalence (%) of pharyngeal responses (p < 0.05), (b) increased number of pharyngeal peaks (p < 0.05), yet pharyngeal frequency (Hz), variability, and stability remain unaffected (p > 0.05), and (c) respiratory changes were unaffected (p > 0.05). Initial and subsequent pharyngeal responses and respiratory rhythm interactions become more distinct with maturation. Interval oromotor experiences and volume-dependent increase in adaptive responses may be contributory. These mechanisms may be important in modulating and restoring respiratory rhythm normalcy.

Effects of Esophageal Acidification on Troublesome Symptoms: An Approach to Characterize True Acid GERD in Dysphagic Neonates

To quantify and compare maximal extent (height) of acid reflux events (AREs) on symptom generation in dysphagic neonates. Dysphagic neonates (N = 53), born at 30 ± 5.3 weeks gestation, underwent 24-hour pH-impedance study for the evaluation of troublesome symptoms purported to be due to gastroesophageal reflux disease (GERD). AREs (pH < 4 for >4 s) detected by impedance (Z) were categorized by maximal extent as refluxate reaching distal (Z6, Z5), middle (Z4, Z3), or proximal (Z2, Z1) impedance channels. AREs reaching the pH sensor only were categorized as distal. Symptom correlation (%, symptom index, symptom sensitivity index, and symptom associated probability) and temporal characteristics (clearance times) of AREs were analyzed using linear mixed and GEE models comparing height categories presented as mean ± SEM, median (IQR), and OR (95% CI). Of the 2003 AREs, 1) distal extent AREs (n = 1642) had increased frequency (p < 0.05), decreased ACT (p < 0.05), and decreased acidity (p < 0.05); 2) in middle and proximal AREs, acid clearance was longer than bolus clearance, (p < 0.01); and 3) the odds of having cardiorespiratory (cough or sneeze) symptoms are increased with proximal and middle AREs (p < 0.05). Most proximal ascent of AREs into middle or proximal esophagus likely activates protective aerodigestive reflexes (peristalsis) or vigilant states to facilitate bolus and chemical clearance. Heightened esophageal sensitivity, acid neutralization delays, or clearance mechanism delays may accentuate multi-systemic troublesome symptoms.

Gestational and postnatal modulation of esophageal sphincter reflexes in human premature neonates

BACKGROUND

Effects of gestational age (GA) and postnatal maturation on upper and lower esophageal sphincter (UES and LES) reflex development remain unclear. We hypothesized very-preterm (VPT) born neonates (< 32 wk GA) have delayed maturation of UES contractile reflex (UESCR) and LES relaxation reflex (LESRR) vs. preterm (PT) born (32-37 wk GA) neonates.

METHODS

Using provocative manometry, effects of 1,263 graded mid-esophageal stimuli (air, liquid) on sensory-motor characteristics of UESCR and LESRR were investigated in 24 VPT-born and 12 PT-born neonates (37.8 ± 0.6 vs. 38.9 ± 0.4 wk postmenstrual age respectively, P = 0.14).

RESULTS

In response to liquid stimuli (vs. air), VPT-born neonates displayed prolonged UESCR and LESRR response latencies (P < 0.001) and prolonged UESCR and LESRR durations (P < 0.01); unlike PT-born neonates, who exhibit prolonged LESRR response latency (P < 0.01), but similar UESCR and LESRR durations (P = 0.2). Differences were noted in LESRR duration in VPT vs. PT neonates for air stimuli (P = 0.04). With liquid stimuli, increasing GA was associated with decreasing response onset latencies to UESCR and LESRR (P < 0.05), and increasing LESRR duration (P = 0.02).

CONCLUSION

Using GA as categorical or continuous variable, vagus-mediated mechano-sensitive and liquid-sensitive reflex characteristics of UESCR and LESRR are distinct; LESRR differs with varying intrauterine maturation suggesting inhibitory modulation progresses with advancing maturation.

Mechanisms of cough provocation and cough resolution in neonates with bronchopulmonary dysplasia

BACKGROUND

Cough and deglutition are protective mechanisms that defend against aspiration. We identified mechanisms associated with cough provocation as well as those associated with cough resolution in infants with bronchopulmonary dysplasia (BPD).

METHODS

Manometry signatures of cough were recognized in 16 premature infants with BPD undergoing concurrent esophageal manometry, respiratory inductance plethysmography, and nasal air flow measurements. Pretussive and post-tussive pharyngo-esophageal motility changes were analyzed. Mechanisms associated with cough and mechanisms that restored respiratory and esophageal normalcy were analyzed.

RESULTS

We analyzed 312 cough events during 88 cough clusters; 97% were associated with recognizable manometric patterns. Initial mechanisms related with coughing included nonpropagating swallow (59%), upper esophageal sphincter (UES) reflex contraction (18%), and lower esophageal sphincter (LES) relaxation (14%). UES and LES dysfunction was present in 69% of nonpropagating swallow-associated cough clusters. Mechanisms restoring post-tussive normalcy included primary peristalsis (84%), secondary peristalsis (8%), and none recognized (8%). UES contraction reflex was associated with cough clusters more frequently in infants on nasal continuous positive airway pressure (NCPAP) (OR = 9.13, 95% CI = 1.88-44.24).

CONCLUSION

Cough clusters in infants with BPD had identifiable etiologies associated with esophageal events; common initial mechanisms were of upper aerodigestive origin, while common clearing mechanisms were peristaltic reflexes.

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.

The role of the superior laryngeal nerve in esophageal reflexes

The aim of this study was to determine the role of the superior laryngeal nerve (SLN) in the following esophageal reflexes: esophago-upper esophageal sphincter (UES) contractile reflex (EUCR), esophago-lower esophageal sphincter (LES) relaxation reflex (ELIR), secondary peristalsis, pharyngeal swallowing, and belch. Cats (N = 43) were decerebrated and instrumented to record EMG of the cricopharyngeus, thyrohyoideus, geniohyoideus, and cricothyroideus; esophageal pressure; and motility of LES. Reflexes were activated by stimulation of the esophagus via slow balloon or rapid air distension at 1 to 16 cm distal to the UES. Slow balloon distension consistently activated EUCR and ELIR from all areas of the esophagus, but the distal esophagus was more sensitive than the proximal esophagus. Transection of SLN or proximal recurrent laryngeal nerves (RLN) blocked EUCR and ELIR generated from the cervical esophagus. Distal RLN transection blocked EUCR from the distal cervical esophagus. Slow distension of all areas of the esophagus except the most proximal few centimeters activated secondary peristalsis, and SLN transection had no effect on secondary peristalsis. Slow distension of all areas of the esophagus inconsistently activated pharyngeal swallows, and SLN transection blocked generation of pharyngeal swallows from all levels of the esophagus. Slow distension of the esophagus inconsistently activated belching, but rapid air distension consistently activated belching from all areas of the esophagus. SLN transection did not block initiation of belch but blocked one aspect of belch, i.e., inhibition of cricopharyngeus EMG. Vagotomy blocked all aspects of belch generated from all areas of esophagus and blocked all responses of all reflexes not blocked by SLN or RLN transection. In conclusion, the SLN mediates all aspects of the pharyngeal swallow, no portion of the secondary peristalsis, and the EUCR and ELIR generated from the proximal esophagus. Considering that SLN is not a motor nerve for any of these reflexes, the role of the SLN in control of these reflexes is sensory in nature only.

Clinical Perspectives on Esophageal Disorders in Infants

Esophageal pathologies are complex and lend themselves to multivariable analysis before a definitive diagnosis can be considered. It is imperative that the clinician establish a methodology for selecting the appropriate technological assessment within scientific testing parameters to establish optimal clinicopathological presentation and determine best practice for patient care.

Impact of personalized feeding program in 100 NICU infants: pathophysiology-based approach for better outcomes

OBJECTIVES

In neonatal intensive care unit infants referred for home-tube feeding methods, we evaluated the effect of an innovative diagnostic and management approach on feeding outcomes at discharge and 1 year, by comparing data from historical controls; we hypothesized that clinical and aerodigestive motility characteristics at evaluation were predictive of feeding outcomes at discharge; we assessed the economic impact of feeding outcomes.

PATIENTS AND METHODS

Patients (N = 100) who were referred for development of long-term feeding management strategy at 46.4 ± 13.1 weeks' postmenstrual age were compared with 50 historical controls that received routine care. The focused approach included swallow-integrated pharyngoesophageal manometry, individualized feeding strategy, and prospective follow-up. Feeding success was defined as ability to achieve oral feedings at discharge and 1 year. Motility characteristics were evaluated in relation to feeding success or failure at discharge.

RESULTS

Higher feeding success was achieved in the innovative feeding program (vs historical controls) at discharge (51% vs 10%, P < 0.0001) and at 1 year (84.3% vs 42.9%, P < 0.0001), at a reduced economic burden (P < 0.05). Contributing factors to the innovative program's feeding success (vs feeding failure) were earlier evaluation and discharge (both P < 0.05), greater peristaltic reflex-frequency to provocation (P < 0.05), normal pharyngeal manometry (P < 0.05), oral feeding challenge success (P < 0.05), and suck-swallow-breath-esophageal swallow sequence (P < 0.05). Probability of feeding success demonstrated a prediction rate of 79.6%.

CONCLUSIONS

Short-term and long-term feeding outcomes in complex neonates can be significantly improved with innovative feeding strategies at a reduced cost. Clinical and aerodigestive motility characteristics were predictive of outcomes.

Regurgitation in healthy and non healthy infants

Uncomplicate regurgitation in otherwise healthy infants is not a disease. It consists of milk flow from mouth during or after feeding. Common causes include overfeeding, air swallowed during feeding, crying or coughing; physical exam is normal and weight gain is adequate. History and physical exam are diagnostic, and conservative therapy is recommended. Pathologic gastroesophageal reflux or gastroesophageal reflux disease refers to infants with regurgitation and vomiting associated with poor weight gain, respiratory symptoms, esophagitis. Reflux episodes occur most often during transient relaxations of the lower esophageal sphincter unaccompanied by swallowing, which permit gastric content to flow into the esophagus. A minor proportion of reflux episodes occurs when the lower esophageal sphincter fails to increase pressure during a sudden increase in intraabdominal pressure or when lower esophageal sphincter resting pressure is chronically reduced. Alterations in several protective mechanisms allow physiologic reflux to become gastroesophageal reflux disease; diagnostic approach is both clinical and instrumental: radiological series are useful to exclude anatomic abnormalities; pH-testing evaluates the quantity, frequency and duration of the acid reflux episodes; endoscopy and biopsy are performed in the case of esophagitis. Therapy with H2 receptor antagonists and proton pump inhibitors are suggested.

Pediatric gastroesophageal reflux clinical practice guidelines: joint recommendations of the North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition (NASPGHAN) and the European Society for Pediatric Gastroenterology, Hepatology, and Nutrition (ESPGHAN)

OBJECTIVE

To develop a North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition (NASPGHAN) and European Society for Pediatric Gastroenterology, Hepatology, and Nutrition (ESPGHAN) international consensus on the diagnosis and management of gastroesophageal reflux and gastroesophageal reflux disease in the pediatric population.

METHODS

An international panel of 9 pediatric gastroenterologists and 2 epidemiologists were selected by both societies, which developed these guidelines based on the Delphi principle. Statements were based on systematic literature searches using the best-available evidence from PubMed, Cumulative Index to Nursing and Allied Health Literature, and bibliographies. The committee convened in face-to-face meetings 3 times. Consensus was achieved for all recommendations through nominal group technique, a structured, quantitative method. Articles were evaluated using the Oxford Centre for Evidence-based Medicine Levels of Evidence. Using the Oxford Grades of Recommendation, the quality of evidence of each of the recommendations made by the committee was determined and is summarized in appendices.

RESULTS

More than 600 articles were reviewed for this work. The document provides evidence-based guidelines for the diagnosis and management of gastroesophageal reflux and gastroesophageal reflux disease in the pediatric population.

CONCLUSIONS

This document is intended to be used in daily practice for the development of future clinical practice guidelines and as a basis for clinical trials.

Central pattern generation involved in oral and respiratory control for feeding in the term infant

PURPOSE OF REVIEW

Drinking and eating are essential skills for survival and benefit from the coordination of several pattern generating networks and their musculoskeletal effectors to achieve safe swallows. Oralpharyngoesophageal motility develops during infancy and early childhood, and is influenced by various factors, including neuromuscular maturation, dietary and postural habits, arousal state, ongoing illnesses, congenital anomalies, and the effects of medical or surgical interventions. Gastroesophageal reflux is frequent in neonates and infants, and its role in neonatal morbidity including dysphagia, chronic lung disease, or apparent life-threatening events is not well understood. This review highlights recent studies aimed at understanding the development of oral feeding skills, and cross-system interactions among the brainstem, spinal, and cerebral networks involved in feeding.

RECENT FINDINGS

Functional linkages between suck-swallow and swallow-respiration manifest transitional forms during late gestation through the first year of life, which can be delayed or modified by sensory experience or disease processes, or both. Relevant central pattern generator (CPG) networks and their neuromuscular targets attain functional status at different rates, which ultimately influences cross-system CPG interactions. Entrainment of trigeminal primary afferents accelerates pattern genesis for the suck CPG and transition-to-oral feed in the RDS preterm infant.

SUMMARY

The genesis of within-system CPG control for rate and amplitude scaling matures differentially for suck, mastication, swallow, and respiration. Cross-system interactions among these CPGs represent targets of opportunity for new interventions, which optimize experience-dependent mechanisms to promote safe swallows among newborn and pediatric patients.

Evaluation and management of neonatal dysphagia: impact of pharyngoesophageal motility studies and multidisciplinary feeding strategy

BACKGROUND AND OBJECTIVES

Abnormal swallowing (dysphagia) among neonates is commonly evaluated using the videofluoroscopic swallow study (VSS). Radiological findings considered high risk for administration of oral feeding include nasopharyngeal reflux, laryngeal penetration, aspiration, or pooling. Our aims were to determine pharyngoesophageal motility correlates in neonates with dysphagia and the impact of multidisciplinary feeding strategy.

METHODS

Twenty dysphagic neonates (mean gestation +/- standard deviation [SD] = 30.9 +/- 4.9 weeks; median 31.1 weeks; range = 23.7-38.6 weeks) with abnormal VSS results were evaluated at 49.9 +/- 16.5 weeks (median 41.36 weeks) postmenstrual age. The subjects underwent a swallow-integrated pharyngoesophageal motility assessment of basal and adaptive swallowing reflexes using a micromanometry catheter and pneumohydraulic water perfusion system. Based on observations during the motility study, multidisciplinary feeding strategies were applied and included postural adaptation, sensory modification, hunger manipulation, and operant conditioning methods. To discriminate pharyngoesophageal manometry correlates between oral feeders and tube feeders, data were stratified based on the primary feeding method at discharge, oral feeding versus tube feeding.

RESULTS

At discharge, 15 of 20 dysphagic neonates achieved oral feeding success, and the rest required chronic tube feeding. Pharyngoesophageal manometry correlates were significantly different (P < 0.05) between the primary oral feeders versus the chronic tube feeders for swallow frequency, swallow propagation, presence of adaptive peristaltic reflexes, oral feeding challenge test results, and upper esophageal sphincter tone. VSS results or disease characteristics had little effect on the feeding outcomes (P = NS).

CONCLUSIONS

Swallow-integrated esophageal motility studies permit prolonged evaluation of swallowing reflexes and responses to stimuli under controlled conditions at cribside. The dysfunctional neuromotor mechanisms may be responsible for neonatal dysphagia or its consequences. Manometry may be a better predictor than VSS in identifying patients who are likely to succeed in vigorous intervention programs.

Neuromotor markers of esophageal motility in feeding intolerant infants with gastroschisis

BACKGROUND

Feeding problems in neonates with gastroschisis are commonly attributed to foregut dysmotility. However, the dysmotility mechanisms are not well understood.

OBJECTIVE

Our aim was to differentiate the pharyngoesophageal motility characteristics in neonates with gastroschisis compared with the controls. Specifically, the characteristics of swallowing, upper esophageal sphincter (UES), esophageal body, and lower esophageal sphincter (LES) were evaluated during basal state and upon provocation.

PATIENTS AND METHODS

Surgically repaired and recovered study infants with persistent feeding difficulties (n = 8; 36 +/- 2 weeks gestational age) and controls (n = 8; 38 +/- 2 weeks gestational age) were evaluated at 40 +/- 2 weeks and 42 +/- 2.5 weeks postmenstrual age, respectively. The basal and adaptive pharyngoesophageal motility characteristics were evaluated using a specially designed esophageal motility catheter with UES and LES sleeves and pneumohydraulic micromanometric water perfusion system at the crib side. Analysis of variance, chi-square, and t tests were applied; data are shown as mean +/- standard deviation, and P < 0.05 was considered significant.

RESULTS

Birth weight was less in gastroschisis (P < 0.03, vs controls) and length was less at motility study (P < 0.01, vs controls). The study group (vs controls) needed prolonged respiratory support (21 +/- 23 vs 1 +/- 2 days; P < 0.001) and prolonged gavage feeding (167 +/- 100 vs 9 +/- 16 days; P < 0.01). Compared with the controls, the gastroschisis group had lower frequency (P < 0.05) and poor propagation of spontaneous swallows (P < 0.001), UES relaxation time was shorter (P < 0.05), rate of relaxation was faster (P < 0.001), and esophageal peristaltic propagation velocity was slower (P < 0.05). Upon esophageal provocation with air and liquids, frequency occurrence of the esophageal reflexes was low (P < 0.05) with respect to primary peristalsis, secondary peristalsis, UES contractile reflex, and LES relaxation reflex.

CONCLUSIONS

In gastroschisis feeding milestones and respiratory milestones were delayed, basal pharyngoesophageal peristaltic failure was common, adaptive peristaltic reflexes were less frequent and failed to occur, and frequency occurrences of UES and LES responses were impaired. These neuromotor markers may provide clues to define the esophageal motor function abnormalities in infants with an abnormality thought to be limited to the intestine.

Correlation of glottal closure using concurrent ultrasonography and nasolaryngoscopy in children: a novel approach to evaluate glottal status

OBJECTIVES

Endoscopic procedures to assess aerodigestive symptoms by evaluating glottal motion are not practical in neonates because of small nares, respiratory difficulties, or additional stress. Our objective was to determine the temporal correlation between concurrent nasolaryngoscopy (NLS) and ultrasonography (USG) evaluation of glottal motion.

METHODS

Simultaneous USG of the glottis was performed in 10 subjects (5 males, 5 females, age = 4.5 months to 7.1 years) that underwent diagnostic flexible outpatient NLS. The USG transducer was placed on the anterior neck at the level of the vocal cords. The video signals from NLS and USG were integrated and synchronized into real-time cine loops of 1-min duration.

RESULTS

Frame-by-frame evaluation of 10,800 frames identifying glottal opening and closure time was compared between the two modalities by three observers and the timing of glottal closure was marked. Two investigators, blinded to NLS images, identified ultrasonographically determined glottal closure with 99% and 100% accuracy, and the mean probability of missing a closure frame was 0.007 (95% CI = 0.0008-0.024).

CONCLUSIONS

Temporal characteristics of glottal motion can be quantified by USG with perfect reliability and safety. This method can be useful in measuring the presence and the duration of laryngeal adduction.

Pharyngeal swallowing: defining pharyngeal and upper esophageal sphincter relationships in human neonates

OBJECTIVE

To test the hypothesis that the sensorimotor characteristics of the reflexes evoked on stimulation with air and water infusions differ by studying the effect of pharyngeal stimulation on pharyngeal-upper esophageal sphincter (UES) interactions in healthy neonates.

STUDY DESIGN

Pharyngo-UES-esophageal manometry was recorded in 10 neonates at 39 +/- 4 weeks postmenstrual age. Pharyngeal infusions (n = 155) of air (0.1 to 2.0 mL) and sterile water (0.1 to 0.5 mL) were given. Two types of reflexes were recognized: pharyngeal reflexive swallowing (PRS) and pharyngo-UES-contractile reflex (PUCR). Frequency occurrence, distribution of reflexes, threshold volume, response time, and stimulus-response relationship were evaluated.

RESULTS

The reflex response rates were 30% for air and 76% for water (P < .001). PRS was more frequent than PUCR with air and water (P < .05), even though the stimulation thresholds and response latencies were similar. Graded volumes of water but not air resulted in an increased frequency of PRS (P < .01).

CONCLUSIONS

PRS is more frequent than PUCR, and the 2 reflexes have distinctive characteristics in air and water stimuli. Both PRS and PUCR have implications for the evaluation of swallowing in infants.

Esophago-glottal closure reflex in human infants: a novel reflex elicited with concurrent manometry and ultrasonography

BACKGROUND AND AIMS

Our aims were to identify and characterize the glottal response to esophageal mechanostimulation in human infants. We tested the hypotheses that glottal response is related to the type of esophageal peristaltic response, stimulus volume, and respiratory phase.

METHODS

Ten infants (2.8 kg, SD 0.5) were studied at 39.2 wk (SD 2.4). Esophageal manometry concurrent with ultrasonography of the glottis (USG) was performed. The sensory-motor characteristics of mechanostimulation-induced esophago-glottal closure reflex (EGCR, adduction of glottal folds upon esophageal provocation) were identified. Mid-esophageal infusions of air (N = 41) were given and the temporal relationships of glottal response with deglutition, secondary peristalsis (SP), and the respiratory phase were analyzed using multinomial logistic regression models.

RESULTS

The frequency occurrence of EGCR (83%) was compared (P < 0.001) with deglutition (44%), SP (34%), and no esophageal responses (22%). The odds ratios (OR, 95% CI) for the coexistence of EGCR with SP (0.4, 0.06-2.2), deglutition (1.9, 0.1-26), and no response (1.9, 0.4-9.0) were similar. The response time for esophageal reflexes was 3.8 (SD 1.8) s, and for EGCR was 0.4 (SD 0.3) s (P < 0.001). Volume-response relationship was noted (1 mL vs 2 mL, P < 0.05). EGCR was noted in both respiratory phases; however, EGCR response time was faster during expiration (P < 0.05).

CONCLUSION

The occurrence of EGCR is independent of the peristaltic reflexes or the respiratory phase of infusion. The independent existence of EGCR suggests a hypervigilant state of the glottis to prevent retrograde aspiration during GER events.

Upstream effect of esophageal distention: effect on airway

The pharyngoesophageal segment of the foregut has an important function in steering clear of luminal contents from the airway, across the age spectrum from a premature neonate to an aging adult. This complex neuromuscular interaction between the esophagus and the airway is maintained by a variety of mechanisms mediated by the parasympathetic and sympathetic afferent and efferent outflows involving the myenteric plexus, glossopharyngeal and vagus cranial nerves, phrenic nerve, and brainstem nuclei. The esophageal provocation during gastroesophageal reflux events results in esophageal distention, followed by responses in the esophagus, the airway, or both. Studies involving esophageal provocation in human adults and animal models are beginning to illuminate the pathogenetic mechanisms associated with aerodigestive tract disease. However, studies pertinent to this topic in infants or children have been lacking. In this paper, we review recent advances concerning the motor responses of the esophagus and the airway ensuing upon esophageal distention. Recent advances in methods to evaluate aerodigestive responses in infants that have been validated are discussed.

Effect of maturation of the magnitude of mechanosensitive and chemosensitive reflexes in the premature human esophagus

OBJECTIVES

To investigate the effect of esophageal mechanosensitive and chemosensitive stimulation on the magnitude and recruitment of peristaltic reflexes and upper esophageal sphincter (UES)-contractile reflex in premature infants.

STUDY DESIGN

Esophageal manometry and provocation testing were performed in the same 18 neonates at 33 and 36 weeks postmenstrual age (PMA). Mechanoreceptor and chemoreceptor stimulation were performed using graded volumes of air, water, and apple juice (pH 3.7), respectively. The frequency and magnitude of the resulting esophago-deglutition response (EDR) or secondary peristalsis (SP), and esophago-UES-contractile reflex (EUCR) were quantified.

RESULTS

Threshold volumes to evoke EDR, SP, or EUCR were similar. The recruitment and magnitude of SP and EUCR increased with volume increments of air and water in either study (P < .05). However, apple juice infusions resulted in increased recruitment of EDR in the 33 weeks group (P < .05), and SP in the 36 weeks group (P < .05). The magnitude of EUCR was also volume responsive (all media, P < .05), and significant differences between media were noted (P < .05). At maximal stimulation (1 mL, all media), sensory-motor characteristics of peristaltic and EUCR reflexes were different (P < .05) between media and groups.

CONCLUSIONS

Mechano- and chemosensitive stimuli evoke volume-dependent specific peristaltic and UES reflexes at 33 and 36 weeks PMA. The recruitment and magnitude of these reflexes are dependent on the physicochemical properties of the stimuli in healthy premature infants.

Gastroesophageal reflux in infancy and childhood

GER is a common reason for pediatric office visits and referrals to a pediatric gastroenterologist. This condition frequently is benign, and it is self-limited in most infants. Although a thorough history and complete physical examination usually are adequate to diagnose GER, a high index of suspicion must be maintained for other diagnoses associated with recurrent emesis, including metabolic disorders, as well as for other gastrointestinal conditions, such as pyloric stenosis and abnormalities of intestinal rotation. Behavioral or lifestyle modification usually can be implemented empirically to diagnose and manage a suspected case of uncomplicated GER. When this fails, medical therapy can be initiated, employing either a step-up or step-down approach with a PPI or H2RA. With the proven efficacy of PPIs and their availability to children, medical treatment has become the mainstay of therapy in severely affected patients; nevertheless, anti-reflux surgery is still widely performed in children with GER. Pediatricians and other primary care providers often manage infants and children who have gastrointestinal complaints, prior to referral to a pediatric gastroenterologist. Hence, they have the responsibility to educate children and families about GER, its natural history, complications, and therapeutic options. A careful history and physical examination, informed use of diagnostic studies, and a consistent approach to medical treatment are important principles that are required to guarantee the success of GER management in infants and children.

Gastroesophageal reflux disease: could intervention in childhood reduce the risk of later complications?

Gastroesophageal reflux (GER) is a ubiquitous disorder in infants. Whereas infants typically outgrow regurgitation by 1 year of age, the prevalence of gastroesophageal reflux disease (GERD) symptoms in those aged 3 to >18 years ranges from 1.8% to 22%. The pathophysiology of GERD in children is similar to that in adults. However, children may present with gastroesophageal and extraesophageal symptoms distinct from classic heartburn. In addition to a growing awareness of the high prevalence of the disorder, increasing evidence supports GERD being a lifelong condition in some individuals that begins in childhood. Although the diagnostic workup in children compared with adults may differ, studies suggest that the early detection and treatment of GERD in childhood may result in better adult disease outcomes, improved quality of life, and decreased overall healthcare burden. Studies of proton pump inhibitor therapy in children confirm high rates of mucosal healing and GER symptom resolution, even in children whose symptoms did not respond to H2-receptor therapy or fundoplication procedures. Omeprazole, lansoprazole, and esomeprazole are formulated as capsules containing enteric-coated granules that can be sprinkled onto applesauce or other soft foods. Lansoprazole is also formulated as strawberry-flavored granules for suspension. These as well as other alternative dosing formulations expand the ability to administer these agents to children. Moreover, long-term studies in adults and in children demonstrate that these agents are safe and well tolerated, even at the higher milligram per kilogram doses that are often required in pediatric patients because of their greater hepatic metabolic capacity.

Supraesophageal complications of gastroesophageal reflux in children: challenges in diagnosis and treatment

Gastroesophageal reflux (GER) occurs throughout the day in healthy infants, children, and adolescents, as well as in adults. However, regurgitation into the pharynx and vomiting are more common in infants than in adults. This places the infant at particular risk for supraesophageal complications of GER. Despite recognition of this risk, a lack of good control data in children and an absence of placebo-controlled treatment trials provide only marginal evidence to support GER as a cause of any supraesophageal disorder in infants or children. An association of GER with "awake apnea," reactive airway disease, and recurrent pneumonia has been demonstrated. Although there is no good evidence to support the efficacy of medical therapy, surgical therapy for GER has been demonstrated to improve symptoms in selected cases with each of these symptom presentations. Although clinical experience and case series suggest that GER may possibly contribute to laryngeal disorders, sinusitis, and otitis media, convincing data are lacking. No studies have definitively demonstrated symptom improvement with medical or surgical therapy for the latter symptom presentations.