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

Brief Resolved Unexplained Events Symptoms Frequently Result in Inappropriate Gastrointestinal Diagnoses and Treatment

OBJECTIVE

To determine associations between presenting symptoms and oropharyngeal dysphagia diagnoses, gastroesophageal reflux disease (GERD) diagnoses, and treatment with acid suppression medication in infants with brief resolved unexplained event (BRUE).

STUDY DESIGN

We performed a prospective cohort study of infants with BRUE to review presenting symptoms and their potential impact on testing and treatment. Videofluoroscopic swallow study (VFSS) results and explanatory diagnoses were obtained from medical record review; acid suppression use was determined by parental survey. Binary and multivariable logistic regression models were used to evaluate associations between presenting symptoms and obtaining VFSS, VFSS results, GERD diagnoses, and acid suppression medication.

RESULTS

Presenting symptoms were varied in 157 subjects enrolled at 51.0 ± 5.3 days of age, with many symptoms that may be related to GERD or dysphagia. Of these, 28% underwent VFSS with 71% abnormal. Overall, 42% had their BRUE attributed to GERD, and 33% were treated with acid suppression during follow-up. Presenting symptoms were significantly associated with the decision to obtain VFSS but not with abnormal VFSS results. Presenting symptoms were also associated with provision of GERD explanatory diagnoses. Both presenting symptoms and GERD explanatory diagnoses were associated with acid suppression use (aOR 2.3, 95% CI 1.03-5.3, P = .04).

CONCLUSIONS

Presenting symptoms may play a role in clinicians' decisions on which BRUE patients undergo VFSS but are unreliable to make a diagnosis of oropharyngeal dysphagia. Presenting symptoms may also influence assignment of GERD explanatory diagnoses that is associated with increased acid suppression medication use.

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.

Characteristics of esophageal refluxate and symptoms in infants compared between pre-treatment and on treatment with proton pump inhibitors

OBJECTIVE

To examine longitudinal pH-impedance characteristics from those infants who remained on proton pump inhibitors therapy for gastroesophageal reflux disease (GERD) as parents/providers refused to discontinue therapy after 4 weeks.

STUDY DESIGN

Eighteen infants with acid reflux index >3% underwent treatment, and pH-impedance data were compared prior to and on proton pump inhibitors at 42 ± 1 and 46 ± 1 weeks' postmenstrual age, respectively. Esophageal acid and bolus exposure, symptoms and swallowing characteristics were examined.

RESULTS

Proton pump inhibitors reduces the acid-mediated effects of reflux but modifies impedance and clearance mechanisms (P < 0.05). Prolonged therapy did not reduce symptoms (P > 0.05). Infants evaluated while on proton pump inhibitors were 1.8 times more likely to have swallows before and after reflux.

CONCLUSIONS

Prescription of proton pump inhibitors for objectively determined GERD should have time limits, as prolonged treatment can result in prolonged esophageal bolus clearance time without relieving symptoms.

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.

The Irritable Infant in the Neonatal Intensive Care Unit: Risk Factors and Biomarkers of Gastroesophageal Reflux Disease

OBJECTIVES

To determine risk factors for arching/irritability in high-risk infants and examine the significance of comorbidity and gastroesophageal reflux (GER) characteristics.

STUDY DESIGN

Retrospective analysis of 24-hour pH-impedance studies of symptomatic infants in a neonatal intensive care unit (ICU) (n = 516, 30.1 ± 4.5 weeks of gestation, evaluated at 41.7 ± 3.2 weeks postmenstrual age) was conducted. Comparisons were made between infants with >72 vs ≤72 arching/irritability events per day. We characterized risk factors for arching/irritability along with clinical, pH-impedance, and outcome correlates.

RESULTS

Of 39 973 arching/irritability events and 42 155 GER events, the averages per day were 77.6 ± 41.0 and 81.7 ± 48.2, respectively. Acid reflux and impedance bolus characteristics were not significantly different between infants with >72 and ≤72 arching/irritability events (P ≥ .05). The odds ratios (ORs) and 95% confidence intervals (CIs) adjusted for postmenstrual age and weight at evaluation were significant for risk factors of preterm birth (2.3 [1.2-4.4]), moderate or severe neuropathology (2.0 [1.1-3.6]), and presence of oral feeding at testing (1.57 [1.07-2.30]).

CONCLUSIONS

Acid GER disease is unlikely the primary cause of arching/irritability and empiric treatment should not be used when arching/irritability is present. Prematurity and neurologic impairment may be more likely the cause of the arching/irritability. Arching/irritability may not be a concern in orally fed infants.

Pharyngeal biorhythms during oral milk challenge in high-risk infants: Do they predict chronic tube feeding?

BACKGROUND

Eating difficulties are common in high-risk neonatal intensive care unit (NICU) infants; mechanisms remain unclear. Crib-side pharyngo-esophageal motility testing is utilized to assess contiguous swallowing physiology, and cross-system interplay with cardio-respiratory rhythms. Aims were to: (1) identify whether distinct pharyngeal rhythms exist during oral milk challenge (OMC), and (2) develop a chronic tube feeding risk prediction model in high-risk infants.

METHODS

Symptomatic NICU infants (N = 56, 29.7 ± 3.7 weeks birth gestation) underwent pharyngo-esophageal manometry with OMC at 40.9 ± 2.5 weeks postmenstrual age (PMA). Exploratory cluster data analysis (partitioning around k-medoids) was performed to identify patient groups using pharyngeal contractile rhythm data (solitary swallows and swallows within bursts). Subsequently, (a) pharyngeal-esophageal, cardio-respiratory, and eating method characteristics were compared among patient groups using linear mixed models, and (b) chronic tube feeding prediction model was created using linear regression.

RESULTS

Three distinct patient groups were identified with validity score of 0.6, and termed sparse (high frequency of solitary swallows), intermediate, or robust (high swallow rate within bursts). Robust group infants had: lesser pharyngeal and esophageal variability, greater deglutition apnea, pharyngeal activity, and esophageal activity (all p < 0.05), but less frequent heart rate decreases (p < 0.05) with improved clinical outcomes (milk transfer rate, p < 0.001, and independent oral feeding at discharge, p < 0.03). Chronic tube feeding risk = -11.37 + (0.22 × PMA) + (-0.73 × bronchopulmonary dysplasia) + (1.46 × intermediate group) + (2.57 × sparse group).

CONCLUSIONS

Robust pharyngeal rhythm may be an ideal neurosensorimotor biomarker of independent oral feeding. Differential maturation of cranial nerve-mediated excitatory and inhibitory components involving foregut, airway, and cardiac rhythms distinguishes the physiologic and pathophysiologic basis of swallowing and cardio-respiratory adaptation.

Significant Temporal Association of Esophageal Air Events (Supragastric Belches, Air Swallows, and Gastric Belches) With Hiccups: A Case Study in an Adolescent

We previously reported our ability to objectively assess the strength of temporal relationships between gastroesophageal reflux (GER) disease-like symptoms with esophageal air events (EAEs) (air swallows, gastric belching, and supragastric belching) using impedance-pH monitoring. Recently, we similarly evaluated an adolescent female who presented to our clinic with symptoms of recurrent hiccups and with what appeared to be numerous EAEs. Hiccups were associated with GER (symptom association probability [SAP] = 100%), air swallows (SAP = 99.7%), supragastric belches (SAP = 100%), and gastric belches (SAP = 100%), with almost twice as many of the supragastric belches preceding a hiccup than any of the other 3 esophageal disturbance types (EDs) (P < 0.00001). Our data showing a significant temporal association between EAEs and hiccups support a previous report in which belching was suspected of being associated with hiccups in an adult male. Reports such as this underscore the importance of considering the assessment of temporal relationships between extra-esophageal symptoms and EDs that include not only GER, but also EAEs, such as air swallows, gastric belches and supragastric belches, when devising strategies for clinical management of patients with hiccups.

Symptom Scores and pH-Impedance: Secondary Analysis of a Randomized Controlled Trial in Infants Treated for Gastroesophageal Reflux

BACKGROUND AND AIMS

To evaluate and compare gastro-esophageal reflux (GER) symptom scores with pH-impedance and test the effects of acid-suppressive medications with or without feeding modifications on pH-impedance in high-risk infants.

METHODS

Infant Gastroesophageal Reflux Questionnaire Revised (I-GERQ-R) and 24-hour pH-impedance data were analyzed from 94 infants evaluated in a tertiary care setting for GER disease. Longitudinal data from 40 infants that received randomized GER therapy (proton pump inhibitor [PPI] with or without feeding modifications) for 4 weeks followed by 1-week washout were analyzed. Relationships between I-GERQ-R and pH-impedance metrics (acid reflux index, acid and bolus GER events, distal baseline impedance, and symptoms) were examined and effects of treatments compared.

RESULTS

(A) Correlations between I-GERQ-R and pH-impedance metrics were weak. (B) I-GERQ-R sensitivity, specificity, and positive predictive values were suboptimal when correlated with pH-impedance metrics. I-GERQ-R negative predictive value (NPV) was high for acid symptom-association probability (NPV = 84%) and distal baseline impedence (NPV = 86%) thresholds. (C) PPI with feeding modifications (vs PPI alone) did not alter pH-impedance metrics or symptom scores (P > .05); however, bolus clearance metrics worsened for both treatment groups (P < .05).

CONCLUSIONS

In high-risk infants (1) I-GERQ-R may be a helpful clinical screening tool to exclude acid-GER disease diagnosis and minimize unnecessary acid-suppressive treatment, but further testing is needed for diagnosis. (2) Acid-suppressive therapy with feeding modifications has no effect on symptom scores or pH-impedance metrics. Clearance of refluxate worsened despite PPI therapy, which may signal development of pharyngoesophageal dysmotility and persistence of symptoms. (3) Placebo-controlled trials are needed in high-risk infants with objective pH-impedance criteria to determine efficacy, safety, and underlying mechanisms. Clinicaltrials.gov ID: NCT02486263.

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.

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.

Feeding Problems and Long-Term Outcomes in Preterm Infants—A Systematic Approach to Evaluation and Management

Preterm infants are known to have long-term healthcare needs. With advances in neonatal medical care, younger and more preterm infants are surviving, placing a subset of the general population at risk of long-term healthcare needs. Oral feeding problems in this population often play a substantial yet under-appreciated role. Oral feeding competency in preterm infants is deemed an essential requirement for hospital discharge. Despite achieving discharge readiness, feeding problems persist into childhood and can have a residual impact into adulthood. The early diagnosis and management of feeding problems are essential requisites to mitigate any potential long-term challenges in preterm-born adults. This review provides an overview of the physiology of swallowing and oral feeding skills, disruptions to oral feeding in preterm infants, the outcomes of preterm infants with feeding problems, and an algorithmic approach to the evaluation and management of neonatal feeding problems.

Mechanisms and management considerations of parent-chosen feeding approaches to infants with swallowing difficulties: an observational study

Videofluoroscopy swallow studies (VFSS) and high-resolution manometry (HRM) methods complement to ascertain mechanisms of infant feeding difficulties. We hypothesized that: (a) an integrated approach (study: parent-preferred feeding therapy based on VFSS and HRM) is superior to the standard-of-care (control: provider-prescribed feeding therapy based on VFSS), and (b) motility characteristics are distinct in infants with penetration or aspiration defined as penetration-aspiration scale (PAS) score ≥ 2. Feeding therapies were nipple flow, fluid thickness, or no modification. Clinical outcomes were oral-feeding success (primary), length of hospital stay and growth velocity. Basal and adaptive HRM motility characteristics were analyzed for study infants. Oral feeding success was 85% [76-94%] in study (N = 60) vs. 63% [50-77%] in control (N = 49), p = 0.008. Hospital-stay and growth velocity did not differ between approaches or PAS ≥ 2 (all P > 0.05). In study infants with PAS ≥ 2, motility metrics differed for increased deglutition apnea during interphase (p = 0.02), symptoms with pharyngeal stimulation (p = 0.02) and decreased distal esophageal contractility (p = 0.004) with barium. In conclusion, an integrated approach with parent-preferred therapy based on mechanistic understanding of VFSS and HRM metrics improves oral feeding outcomes despite the evidence of penetration or aspiration. Implementation of new knowledge of physiology of swallowing and airway protection may be contributory to our findings.

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.

Diagnostic utility of impedance-pH monitoring in infants of diabetic mothers with oral feeding difficulties

OBJECTIVE

To determine the diagnostic utility of impedance-pH monitoring in infants of diabetic mothers (IDM) with oral feeding difficulties.

STUDY DESIGN

Retrospective review of a consecutive sample of 50 IDM who had impedance-pH monitoring for objective gastroesophageal reflux disease (GERD) diagnosis. Acid reflux index (ARI) ≥ 7 was considered pathological (ARI+).

RESULTS

Impedance-pH monitoring was performed at 42.1-week postmenstrual age. Twenty infants (40%) with ARI+ compared to 30 with ARI < 7 (ARI-). ARI+ had lower weight at study vs. ARI- (p < 0.05). ARI+ had significantly higher reflux parameters but had similar symptom burden and symptom-association scores vs. ARI-. All ARI+ received proton-pump inhibitors (PPI) vs. 7 (23.3%) in ARI- (p < 0.05), but oral feeding outcomes, gastrostomy rate, growth, and hospital length of stay were similar in both groups.

CONCLUSIONS

The diagnostic yield of impedance-pH monitoring in IDM is about 40%. However, GERD diagnosis or treatment with PPI did not modify short-term clinical outcomes.

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.

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.

Mechanisms of bradycardia in premature infants: Aerodigestive-cardiac regulatory-rhythm interactions

OBJECTIVE

Eating difficulties coupled with cardiorespiratory spells delay acquisition of feeding milestones in convalescing neonates, and the mechanisms are unclear. Aims were to examine and compare the pharyngoesophageal-cardiorespiratory (PECR) response characteristics: (a) in control neonates and those with recurrent bradycardia spells; and (b) during pharyngeal stimulation when bradycardia occurs versus when no bradycardia occurs.

METHODS

Preterm infants (N = 40, 27 ± 3 weeks gestation), underwent concurrent pharyngoesophageal manometry, electrocardiography, respiratory inductance plethysmography, and nasal airflow thermistor to evaluate pharyngoesophageal motility, heart rate (HR), and respiration during graded abrupt pharyngeal sterile water stimuli. Infants with recurrent bradycardia (N = 28) and controls (N = 12) were evaluated at 38 (38-40) and 39 (38-40) weeks postmenstrual age, respectively. Comparisons were performed (a) between study and control groups; and (b) among HR responses of <80 BPM, 80-100 BPM, and >100 BPM.

RESULTS

Overall, characteristics of PECR responses in infants with a history of recurrent bradycardia (vs. controls) did not differ (p > .05). However, when pharyngeal stimulus induced severe bradycardia (<80 BPM): prolonged respiratory rhythm change, increased pharyngeal activity, increased esophageal dysmotility (as evidenced by prolonged esophageal inhibition and motor activity), and prolonged lower esophageal sphincter relaxation were noted (all p < .05).

CONCLUSIONS

In control infants and those with recurrent bradycardia, pharyngeal stimulation results in similar PECR response characteristics. However, when severe bradycardia occurs, PECR response characteristics are distinct. The mechanisms of severe bradycardia spells are related to abnormal prolongation of vagal inhibitory effects on cardiorespiratory rhythms in conjunction with prolonged esophageal inhibition and delays with terminal swallow.

Approach to Feeding Difficulties in Neonates and Infants: A Comprehensive Overview

Deglutition disorders (DD) can be transient and considered as physiologic during normal maturation. However, when oral feeding milestones are impaired and bothersome symptoms and aerodigestive consequences are associated, it is interpreted as DD with varying specific entities, such as feeding difficulties, swallowing disorders, aerodigestive illness, and aspiration syndromes. Symptoms related to DD are heterogeneous and managed empirically. This article clarifies current controversies, explains the potential role of safe feeding and physiologic and pathophysiologic perspectives, and highlights current advances in the field. Evidence basis for diagnostic strategies is discussed, and involves evaluation for structure and function tests, and nutrition and feeding assessment.

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.

Neonatal Aerodigestive Disorders: Epidemiology and Economic Burden

Aerodigestive disorders, those affecting the upper and lower airway or upper gastrointestinal tract, are interrelated anatomically during fetal development and functionally after birth. Successful respiration and feeding requires careful coordination to promote effective swallowing and prevent aspiration. I describe the epidemiology, including the prevalence of the most common aerodigestive disorders. The ability of an infant to feed by mouth at discharge, without a surgically placed feeding tube, is an important neurodevelopmental marker. Therefore, aerodigestive disorders have a high potential for lifelong morbidities and health care expenditures. When available, published research on related medical costs for these disorders is provided.

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.

Novel Use of Impedance Technology Shows That Esophageal Air Events Can Be Temporally Associated With Gastroesophageal Reflux Disease-like Symptoms

A few studies have shown that esophageal air events (EAEs), such as air-swallows, may be associated with symptoms that have historically been associated with gastroesophageal reflux disease (GERD). To objectively test a hypothesis that all EAE types (air-swallows, supragastric belches and gastric belches) can be associated with GERD-like symptoms, we removed the impedance "tags" from the GER episodes (placed during autoscan) and instead tagged either air-swallows, supragastric belches or gastric belches in each of 3 copies of the 24-hour impedance tracing for 2 infant patients who presented with symptoms suggestive of GER as an etiology. Impedance system software (MMS) analyses revealed that, in both infants, all EAE types were significantly associated (SAP >95%) with 1 or more of the GERD-like symptom types (cough, pain/crying, back-arching, and gagging). These data underscore the importance of considering other diagnoses when developing management strategies for treating GERD-like symptoms in infants.