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

Acoustic and Perceptual Profiles of Swallowing Sounds in Preterm Neonates: A Cross-Sectional Study Cohort

Cervical auscultation, commonly used by speech-language pathologists in some countries as an adjuvant to the clinical feeding evaluation, requires data on acoustic and perceptual profiles of swallowing sounds. Whilst these exists in adults and children, none currently exist for preterm neonates. Our study aims to establish the acoustic and perceptual parameters of swallowing sounds in preterm neonates. Swallowing sounds were recorded on a digital microphone during oral feeding observations. Acoustic parameters of duration, peak frequency, peak power and peak intensity were determined. Perceptual parameters heard pre, during and post-swallows were rated as 'present', 'absent', or 'cannot be determined'. Eighty preterm neonates (43 males; mean age = 33.4 weeks [SD 2.6]) from three Australian special care nurseries demonstrated mean swallow durations of < 1 s. The peak amplitude correlated with the number of medical co-morbidities (r = 0.24; 95%CI 0.03-0.45). Most preterm neonates have coordinated swallows that are loud, quick and completed in < 1 s. The perceptual parameters of a bolus transit sound was consistently present in all preterm neonates. One in five pre-term neonates have an uncoordinated swallow where wheeze, stridor or wet breath sounds were present post-swallow. Our study provides clinicians with acoustic and perceptual parameters to guide use of cervical auscultation in special care nurseries. Future studies should consider simultaneous instrumental assessment to ensure validity when using cervical auscultation to support diagnostic decision-making on swallowing coordination.

Prevalence of Oropharyngeal Dysphagia in Children: A Systematic Review and Meta-Analysis

OBJECTIVE

This study aims to determine the prevalence of oropharyngeal dysphagia (OD) in children, as diagnosed through instrumental evaluation, and to identify associated risk factors.

METHODS

A systematic search was conducted across six databases (Embase, LILACS, LIVIVO, PubMed/MEDLINE, Scopus, and Web of Science), as well as gray literature sources (ASHA, Google Scholar, and ProQuest). Studies involving children (under 12 years of age), diagnosed using instrumental methods such as videofluoroscopic swallow study (VFSS) or fiberoptic endoscopic evaluation of swallowing (FEES), were included. A random-effects meta-analysis was performed to estimate the prevalence, with heterogeneity assessed through meta-regression. The risk of bias was evaluated using the Joanna Briggs Institute Critical Appraisal Checklist.

RESULTS

A total of 31 studies were included, yielding a pooled prevalence estimate of 69% (95% CI: 61%-77%; I² = 94%). Most studies involved children with predisposing conditions, potentially contributing to an overestimation of OD prevalence in the general pediatric population. Four studies were assessed as having a moderate risk of bias, while 27 were rated as having a low risk of bias.

CONCLUSION

The findings suggest a high prevalence of OD, especially in children with underlying health conditions. These results underscore the importance of early diagnosis and tailored interventions to mitigate the health risks associated with deglutition disorders in pediatric populations.

Evaluation of feeding difficulties using videofluoroscopic swallow study and swallowing therapy in infants and children

BACKGROUND

Infants and children with feeding difficulties have swallowing dysfunction and high risk of aspiration, which could be silent without choking, resulting in recurrent pneumonia and long-term respiratory morbidity. Videofluoroscopic swallow study (VFSS) is a useful tool for real-time visualization of the swallowing process and airway aspiration. This study reported a single-institutional 10-year experience of VFSS in pediatric patients with feeding difficulties and the efficacy of swallowing therapy.

METHODS

From 2011 to 2020, 30 infants and children with feeding difficulties received VFSS examinations in a medical center at a median age of 19 months (range 7 days-8 years). The images of the swallowing process (oral phase, triggering of pharyngeal swallowing, and pharyngeal phase) under videofluoroscopy were analyzed by a radiologist and a speech-language pathologist. Aspiration severity was assessed from VFSS observations and rated by an eight-point Penetration-Aspiration-Scale (PAS), with higher scores indicating increased severity. Swallowing therapy was performed by experienced speech-language therapists, and follow-up of oral feeding tolerance and risk of aspiration pneumonia was done.

RESULTS

Of the 30 patients, 24 (80%) had neurological deficits. High PAS scores (6-8) were observed in 25 (83.4%) patients, and 22 had a PAS score of 8, indicating silent aspiration. Of the 25 patients with high PAS scores, 19 (76%) had neurological deficits, and 18 (72%) depended on tube feeding at a median age of 20 months. Swallowing problems occurred most frequently during the pharyngeal phase in the patients with high PAS scores. VFSS-based swallowing therapy improved oral feeding ability and reduced aspiration episodes.

CONCLUSION

Infants and children with swallowing dysfunction and neurological deficits had high risk of severe aspiration. Swallowing problems in the pharyngeal phase were the most common VFSS findings in patients with severe aspiration. VFSS may help guide problem-oriented swallowing therapy to reduce the risk of recurrent aspiration.

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.

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.

Filling the Gaps for Feeding Difficulties in Neonates With Hypoxic-Ischemic Encephalopathy

Hypoxic-ischemic encephalopathy (HIE) in neonates poses long-term feeding difficulties and abnormalities of swallowing, the sequel of which is growth impairment. Such infants are also at risk of impaired self-feeding in the grown-up stage along with other motor and tone abnormalities leading to malnutrition and multiple aspiration pneumonia episodes. The lack of evidence-based and pragmatic feeding strategies in such neonates is because of varied unrecognized symptoms and lacking validated diagnostic approaches. This article approaches evidence related to the pathophysiologic basis of feeding difficulties in neonates with HIE as well as standardizing measures and techniques to improve the feeding abilities of such babies and, in turn, their long-term development. The present review provides a scaffold for putting importance on this less taken care issue of feeding problems and emphasizes that more objective and evidence-based studies are required to be added to the literature for early interventions and management of this issue so that caregivers and neonatologists are not misguided by crude subjective opinions.

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.

Developing a Quality Improvement Feeding Program for NICU Patients

Practices in NICUs vary widely, particularly when clinical decisions involve complex tasks and multiple disciplines, which occurs with feeding preterm infants. Neonatal feeding difficulties in preterm infants often lead to prolonged tube feeding and therefore lengthened hospital stays. Education and compliance with evidence-based protocols and guidelines are needed on the initiation of feedings and feeding advancement to transform enteral and oral feeding practices and thus reduce practice variation and improve clinical outcomes.

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.

Infant aspiration and associated signs on clinical feeding evaluation

OBJECTIVES

Few studies have examined clinical signs of aspiration in infants <51 weeks post-menstrual age (PMA) for whom the laryngeal cough reflex is not fully developed. This retrospective study explored 1) the association between signs of aspiration on a clinical feeding evaluation (CFE) and/or comorbid conditions with aspiration (silent or overt) on a modified barium swallow study (MBS) for infants in this age range, 2) the association between lower respiratory infection (LRI) and aspiration on MBS, and 3) the sensitivity and specificity of detecting aspiration according to signs on CFE and the evaluating speech-language pathologist's (SLP) years of experience.

METHODS

A retrospective review of charts of patients with MBS completed January 1, 2012-December 31, 2014 was performed. Patients were included if they were <51-weeks PMA at the time of MBS and had a CFE conducted no more than seven days prior to the MBS. Patient age, comorbidities, and MBS and CFE details were collected. The impact of CFE findings, patient age, comorbid syndromes/associations, and aerodigestive diagnoses on the odds of demonstrating silent aspiration (SA) or overt aspiration during MBS with thin liquids was determined using logistic regression, and the sensitivity and specificity of CFE for identifying SA was calculated.

RESULTS

Results from 114 patients indicated that 46 (40 %) of the infants had SA and nine (8 %) had overt aspiration on MBS. Notable signs on CFEs were cough (36 %), oxygen desaturations (33 %), and chest congestion (32 %). On multiple regression analysis there was increased odds of SA on MBS with at least one clinical sign on CFE (OR: 24.3, p = 0.02), chronic lung disease, (OR: 18.2, p = 0.01), and airway abnormalities (OR: 2.94, p = 0.01). Cough on CFE was associated with increased odds of overt aspiration on MBS (OR: 5.69, p = 0.04). Neither SA nor overt aspiration were significantly associated with LRI. Sensitivity and specificity of CFE for correctly identifying the presence of SA were 98 % and 15 %, respectively; experience of the SLP was not a contributing factor.

CONCLUSION

Further study is required to determine if specific signs on CFE are predictive of aspiration.

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.

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.

The Impact of the American Academy of Pediatrics Brief Resolved Unexplained Event Guidelines on Gastrointestinal Testing and Prescribing Practices

OBJECTIVES

To determine if hospitalization, testing, diagnosis, and management of suspected gastroesophageal reflux, and follow-up visits decreased since introduction of American Academy of Pediatrics guidelines for brief resolved unexplained events (BRUEs).

STUDY DESIGN

We performed a retrospective cohort study of infants with BRUE evaluated at Boston Children's Hospital in the year before and after guideline implementation to determine if practice patterns have changed. Outcomes included hospitalization rates, frequency of swallow assessments, other diagnostic testing, and reflux diagnoses, cost of care, and number of repeat visits. Groups were compared based on whether they presented before or after guideline implementation.

RESULTS

In total, 359 subjects (186 pre-, 173 post-guidelines) were identified. There were no significant differences in practice patterns or outcomes before or after guideline implementation. Subjects had mean age 2.53 ± 0.15 months, and 80% were hospitalized for 2.49 ± 0.26 days. Each subject had 2.47 diagnostic tests performed, and 89% were noncontributory. Despite only 13% having videofluoroscopic swallow study performed, 72% showed aspiration/penetration. No subject had gastroesophageal reflux testing, yet reflux was implicated as the cause for admission in 40% of subjects, resulting in increased odds of discharge on acid suppressing medications (OR 2.88, 95% CI 1.68-4.92, P = .0001). In follow-up, 28% of subjects had repeat hospitalizations or emergency department visits for persistent symptoms.

CONCLUSIONS

Infants with BRUE continue to undergo low-yield diagnostic testing and after admission remain symptomatic and frequently re-present to medical care. Swallow testing remains infrequent despite its high-yield, reflux continues to be implicated and children are still being discharged on acid suppression despite lack of efficacy.

Pharyngeal contractile and regulatory characteristics are distinct during nutritive oral stimulus in preterm-born infants: Implications for clinical and research applications

BACKGROUND

Maturation of pharyngeal swallowing during neonatal oral feeding is unknown. Our objective was to evaluate pharyngeal functioning using high-resolution manometry (HRM) during nutritive oral stimulus and test the hypothesis that pharyngeal contractility and regulation are distinct in preterm-born infants.

METHODS

High-resolution manometry data during oral milk feeding were analyzed for pharyngeal contractile (PhCI, mm Hg cm s) and regulatory (number and frequency of pharyngeal contractions and bursts, pharyngeal activity-to-quiescence ratio, upper esophageal sphincter nadir pressure) characteristics in 23 preterm (<38 weeks' gestation) and 18 full-term-born infants at term maturation. Mixed linear models and stepwise regression methods were used.

RESULTS

Despite more oral feeding experiences (P < 0.05), preterm infants (vs full-term), consumed less milk volume (P < 0.001), had lesser pharyngeal contractions within bursts (P = 0.04), lower pharyngeal contraction frequency (P < 0.01), and lower pharyngeal activity (P = 0.03), but higher PhCI per individual contraction (P = 0.01). PhCI is higher for longer PMA (P < 0.05), higher UES nadir pressures (P < 0.05), and lower pharyngeal contraction frequency (P < 0.05).

CONCLUSIONS

Nutritive oral milk stimulus provoked pharyngeal contractility characteristics is distinct in preterm-born. Despite more oral nutritive experiences, preterm infants had underdeveloped excitatory and inhibitory rhythmic activity. Cranial nerve IX and X effects on sensory-motor responses and feedback (excitation-inhibitory rhythm regulation) remain immature among preterm-born even at full-term maturational status. We speculate the relationship between PhCI and UES regulatory activity contributes to the observed differences in preterm and full-term infants.

Feeding Interventions Are Associated With Improved Outcomes in Children With Laryngeal Penetration

OBJECTIVES

To determine if children with laryngeal penetration on videofluoroscopic swallow study (VFSS) who received feeding interventions (thickened liquids, change in liquid flow rate, and/or method of liquid delivery) had improved symptoms and decreased hospitalizations compared with those without intervention.

METHODS

We performed a retrospective cohort study of children under 2 years with laryngeal penetration on VFSS at our institution in 2015 to determine initial and follow-up VFSS findings, symptom improvement at follow-up, and hospitalization risk before and after VFSS. Proportions were compared with Fisher exact test and hospitalizations with paired t tests.

RESULTS

We evaluated 137 subjects with age 8.93 ± 0.59 months who had laryngeal penetration without aspiration on VFSS. Fifty-five percent had change in management, with 40% receiving thickening and 15% a change in flow rate. There was significant improvement in symptoms for children that had feeding intervention and this improvement was the greatest with thickening (OR 41.8, 95% CI 12.34-141.69, P < 0.001). On repeat VFSS, 26% had evidence of aspiration that was not captured on initial VFSS. Subjects had decreased total and pulmonary hospitalizations with feeding intervention and decreased pulmonary nights with thickening (P < 0.05).

CONCLUSIONS

Laryngeal penetration appears to be clinically significant in children with oropharyngeal dysphagia and interventions to decrease its occurrence are associated with improved outcomes including decreased symptoms of concern and hospitalization nights. Thickening or other feeding intervention should be considered for all symptomatic children with laryngeal penetration on swallow study.

Piecemeal Deglutition and the Implications for Pressure Impedance Dysphagia Assessment in Pediatrics

OBJECTIVES

High-resolution impedance manometry (HRIM) enables biomechanical swallow assessment. Piecemeal deglutition (PD) defines swallowing of a single bolus in 2 or more portions. We investigated PD sequences on HRIM recordings to ascertain appropriate swallow selection for analysis and to determine the impact of PD on swallow function measures.

METHODS

Pharyngo-esophageal motility and bolus flow were assessed in 27 children (19 M, mean age 15 months) with repaired esophageal atresia and trachea-esophageal fistula, but who were asymptomatic of oropharyngeal dysphagia. A consistent volume of between 2 and 5 mL saline boluses was given to each patient. Retrospectively, PD sequences were defined based on the number of swallows required to clear the bolus from the oral cavity: pattern A = 1-2 swallows; pattern B = 3 swallows; and pattern C = 4+ swallows. The largest bolus volume swallowed was noted as the dominant swallow in each pattern. Pressure Flow Analysis defined contractility, distension and flow timing metrics. Data were averaged for each PD pattern, and compared with dominant swallows from each pattern.

RESULTS

PD pattern B (43.7%) was the most prevalent across the cohort. PD patterns were similarly distributed across age groups (G1: <1 years, G2: 1-4 years). Differences in upper esophageal sphincter distension and pharyngeal flow timing measures were, however, seen in relation to both age and PD pattern, whereby a larger pharynx in older children elicited greater distension for a longer latency, and for larger volumes.

CONCLUSIONS

PD reduces bolus volume, and biomechanical swallow measures are impacted. PD is a necessary consideration for accurate HRIM analysis of swallow function. Selection of dominant swallows from a PD sequence provides a swallow profile which best represents a child's swallow function, and should always be reported and interpreted in context of the PD sequence observed.

Presenting Signs and Symptoms do not Predict Aspiration Risk in Children

OBJECTIVES

To determine if any presenting symptoms are associated with aspiration risk, and to evaluate the reliability of clinical feeding evaluation (CFE) in diagnosing aspiration compared with videofluoroscopic swallow study (VFSS).

STUDY DESIGN

We retrospectively reviewed records of children under 2 years of age who had evaluation for oropharyngeal dysphagia by CFE and VFSS at Boston Children's Hospital and compared presenting symptoms, symptom timing, and CFE and VFSS results. We investigated the relationship between symptom presence and aspiration using the Fisher exact test and stepwise logistic regression with adjustment for comorbidities. CFE and VFSS results were compared using the McNemar test. Intervals from CFE to VFSS were compared using the Student t test.

RESULTS

A total of 412 subjects with mean (±SD) age 8.9 ± 6.9 months were evaluated. No symptom, including timing relative to meals, predicted aspiration on VFSS. This lack of association between symptoms and VFSS results persisted even in the adjusted multivariate model. The sensitivity of CFE for predicting aspiration by VFSS was 44%. Patients with a reassuring CFE waited 28.2 ± 8.5 days longer for confirmatory VFSS compared with those with a concerning CFE (P < .05).

CONCLUSIONS

Presenting symptoms are varied in patients with aspiration and cannot be relied upon to determine which patients have aspiration on VFSS. The CFE does not have the sensitivity to consistently diagnose aspiration so a VFSS should be performed in persistently symptomatic patients.

Defining pharyngeal contractile integral during high-resolution manometry in neonates: a neuromotor marker of pharyngeal vigor

BACKGROUND

Pharyngeal contractility is critical for safe bolus propulsion. Pharyngeal contractile vigor can be measured by Pharyngeal Contractile Integral (PhCI): product of mean pharyngeal contractile amplitude, length, and duration. We characterized PhCI in neonates and examined the hypothesis that PhCI differs with mode of stimulation.

METHODS

Nineteen neonates born at 38.6 (34-41) weeks gestation were evaluated at 42.9 (40.4-44.0) weeks postmenstrual age using high-resolution manometry (HRM). PhCI was calculated using: (a) Conventional and (b) Automated Swallow Detection algorithm (ASDA) methods. Contractility metrics of all pharyngeal regions were examined using mixed statistical models during spontaneous and adaptive state (pharyngeal and oral stimulus) swallowing.

RESULTS

PhCI of oral stimuli swallows were distinct from pharyngeal stimuli and spontaneous swallows (P < 0.05). Correlation between conventional and ASDA methods was high (P < 0.001). PhCI increased with swallows for pharyngeal stimulation (P < 0.05) but remained stable for swallows with oral stimulation. PhCI differed between proximal and distal pharynx (P < 0.001).

CONCLUSIONS

PhCI is a novel reliable metric capable of distinguishing (1) proximal and distal pharyngeal activity, (2) effects of oral and pharyngeal stimulation, and (3) effects of prolonged stimulation. Changes in pharyngeal contractility with maturation, disease, and therapies can be examined with PhCI.

Stress Signals During Sucking Activity Are Associated With Longer Transition Time to Full Oral Feeding in Premature Infants

Several treatments have been proposed to shorten the time to the attainment of full oral feeding (FOF) for premature infants, but there are only a few evaluation methods useful in estimating predictors of this period. We investigated whether specific items within the disorganized sucking patterns described by the Neonatal Oral-Motor Assessment Scale (NOMAS) could estimate the time to FOF in preterm infants with feeding difficulty. Preterm infants diagnosed with a disorganized sucking pattern in the NOMAS evaluation before 50 weeks of postmenstrual age were included. Video recordings of at least 2 min of oral feeding were further analyzed retrospectively by two assessors and the premature infants who exhibited disorganized sucking patterns (n = 109) were divided into three clusters (clusters 2-4). The observational items compatible with disorganization in the original NOMAS were divided into three groups: cluster 2 (disorganized: arrhythmical), cluster 3 (disorganized: arrhythmical + unable to sustain), and cluster 4 (disorganized: arrhythmical + incoordination ± unable to sustain) and further divided into incoordination-positive (cluster 4) and incoordination-negative groups (clusters 2 and 3). Premature infants in the incoordination-positive group (cluster 4, which means stress signals) showed a median transition time of 22 days (range: 4-121 days) which was longer than that in the incoordination-negative group (median 6 days; range: 1-25 days). Univariate linear regression analysis revealed that the presence of incoordination among disorganized sucking patterns (NOMAS cluster 4 vs. clusters 2 and 3), birth weight, total parenteral nutrition (TPN) duration, non-invasive positive pressure ventilation duration, the presence of moderate to severe bronchopulmonary dysplasia, pulmonary hypertension, sepsis, small for gestational age (SGA), and necrotizing enterocolitis are associated with the transition time to FOF. In a multivariate linear regression analysis, the variables revealed to be associated with the transition time were TPN duration, SGA, and the presence of stress signals (incoordination-positive group) among disorganized sucking patterns. When selecting premature infants to be treated with swallowing therapy, it is reasonable to pay more attention to the incoordination-positive group described in the NOMAS, that is, premature infants with stress signals to shorten the time to attain FOF.

Feeding Methods at Discharge Predict Long-Term Feeding and Neurodevelopmental Outcomes in Preterm Infants Referred for Gastrostomy Evaluation

OBJECTIVE

To test the hypothesis that oral feeding at first neonatal intensive care unit discharge is associated with less neurodevelopmental impairment and better feeding milestones compared with discharge with a gastrostomy tube (G-tube).

STUDY DESIGN

We studied outcomes for a retrospective cohort of 194 neonates <37 weeks' gestation referred for evaluation and management of feeding difficulties between July 2006 and July 2012. Discharge milestones, length of hospitalization, and Bayley Scales of Infant Development-Third Edition scores at 18-24 months were examined. χ², Mann-Whitney U, or t tests and multivariable logistic regression models were used.

RESULTS

A total of 60% (n = 117) of infants were discharged on oral feedings; of these, 96% remained oral-fed at 1 year. The remaining 40% (n = 77) were discharged on G-tube feedings; of these, 31 (40%) remained G-tube dependent, 17 (22%) became oral-fed, and 29 (38%) were on oral and G-tube feedings at 1 year. Infants discharged on a G-tube had lower cognitive (P <.01), communication (P = .03), and motor (P <.01) composite scores. The presence of a G-tube, younger gestation, bronchopulmonary dysplasia, or intraventricular hemorrhage was associated significantly with neurodevelopmental delay.

CONCLUSIONS

For infants referred for feeding concerns, G-tube evaluations, and feeding management, the majority did not require a G-tube. Full oral feeding at first neonatal intensive care unit discharge was associated with superior feeding milestones and less long-term neurodevelopmental impairment, relative to full or partial G-tube feeding. Evaluation and feeding management before and after G-tube placement may improve long-term feeding and neurodevelopmental outcomes.

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.

Using devices to upregulate nonnutritive swallowing in typically developing infants

The role of various sensory stimuli for stimulating swallowing in infants may be of importance for assisting infants to develop oral feeding. We evaluated the swallowing mechanism response to two devices for increasing the rate of nonnutritive swallowing in two typically developing infant age groups, ages 2-4 mo and 7-9 mo. One device was a pacifier familiar to the infant; the other was a small vibrator placed on the skin overlying the thyroid cartilage. The rate of nonnutritive swallowing while infants were awake was compared in three 10-min conditions: at rest without stimulation (spontaneous); during nonnutritive sucking with a pacifier; and over 10 min containing 18 epochs of vibratory stimulation for 10 s each. To assess whether vibration on the throat over the laryngeal area altered respiration, the mean cycle length was compared between 10-min intervals either containing vibratory stimulation or without stimulation at rest. Both the pacifier and laryngeal vibration stimulation doubled the rate of swallowing in the infants with a mean age of 3 mo 16 days and infants with a mean age of 8 mo 8 days. No differences occurred in the mean respiratory cycle length between intervals with and without vibration in either age group. Results suggest that nonnutritive sucking, vibration, or both might be beneficial in enhancing swallowing in young infants. Because vibration on the neck would not interfere with oral transfer of liquid, it might provide additional stimulation for swallowing during oral feeding. Both stimulation types should be evaluated for enhancing swallowing in infants with immature swallowing skills.

Dysphagia in the high-risk infant: potential factors and mechanisms

Neonatal dysphagia, or abnormalities of swallowing, represent a major global problem, and consequences of dysfunctional feeding patterns carry over into infancy and toddler age groups. Growth, development, and independent feeding skills are all delayed among high-risk infants. Such a group comprises premature birth, low-birth-weight, congenital anomalies, perinatal asphyxia, postsurgical, and sepsis categories. The conflict between pathophysiologic and pragmatic feeding strategies remains a major conundrum and is largely due to a lack of validated diagnostic approaches amid heterogeneity of the patient phenotype. Thus, well-tested feeding management strategies that can be generalizable are lacking. Furthermore, the aerodigestive symptoms and signs, potential risk factors, and contributory etiologies remain nonspecific. This article presents mechanistic evidence related to the pathophysiologic basis of neonatal dysphagia as well as potential opportunities to improve feeding abilities and long-term development.

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.

Pediatric Dysphagia: Physiology, Assessment, and Management

Infancy and childhood represent a time of unparalleled physical growth and cognitive development. In order for infants and children to reach their linear and neurological growth potential, they must be able to reliably and safely consume sufficient energy and nutrients. Swallowing difficulties (dysphagia) in pediatric populations can have a detrimental effect on dietary intake and, thus, growth and development. As a result, it is imperative to accurately identify and appropriately manage dysphagia in pediatric populations. This article provides an overview of dysphagia in children, as well as common causes of childhood swallowing difficulties, populations at risk for pediatric dysphagia, techniques used to assess swallowing in pediatric patients, and the current treatment options available for infants and children with dysphagia.

Systematic review of interventions used in or relevant to occupational therapy for children with feeding difficulties ages birth-5 years

Research articles on the effectiveness of feeding interventions for infants and young children were identified, appraised, and synthesized. Thirty-four studies met the inclusion criteria and were reviewed. Three broad intervention themes regarding feeding approaches were identified on the basis of their theoretical orientations. These three feeding approaches were (1) behavioral interventions, (2) parent-directed and educational interventions, and (3) physiological interventions. Synthesis of the evidence suggested that various feeding approaches may result in positive outcomes in the areas of feeding performance, feeding interaction, and feeding competence of parents and children. This synthesis of empirical evidence supporting interventions for feeding problems provides a foundation for future research to define the types of outcomes that can be expected for children with different diagnoses or functional impairments and to develop best practice guidelines.

Physiology of esophageal sensorimotor malfunctions in neonatal neurological illness

We aimed to define the sensorimotor characteristics of aero-digestive reflexes evoked upon midesophageal provocations in neuropathology infants. Provocative esophageal motility testing was performed in 20 neuropathology infants and 10 controls at 42.3 ± 0.6 and 38.9 ± 0.9 wk postmenstrual age. Data from 1,073 infusions were examined for the sensory thresholds, response frequencies, response magnitude of upper esophageal sphincter (UES) contractile reflexes, lower esophageal sphincter (LES) relaxation reflexes, and peristaltic reflexes using mixed statistical models. Threshold volumes for air and liquid in neuropathology and control infants were similar for all reflexes. Graded air- and liquid volume-dependent UES contractile reflex, LES relaxation reflex, and peristaltic reflex frequency recruitment were present in neuropathology and control subjects for the media (P < 0.0001) and the reflexes (P < 0.0001). In neuropathology infants (vs. controls), UES contractile magnitude is higher (P < 0.0001); LES relaxation reflex occurred earlier (P = 0.008); LES nadir duration lasted longer (P = 0.006); secondary peristalsis is the chief method of esophageal clearance (P < 0.0001); pharyngeal swallows and deglutition apneas are less frequent (P = 0.001); proximal, midesophageal waveform magnitudes and duration are exaggerated (P < 0.008). UES contractile reflex was longer with liquid than air in both groups (P = 0.03). We concluded that 1) perception to midesophageal provocation remains preserved in neuropathology neonates; 2) sustained and exaggerated myogenic response from afferent activation is evident by increased excitatory efferent outputs to the UES and esophageal body and increased inhibitory efferent outputs to the LES; 3) dysfunctional regulation of pharyngeal swallowing and infrequent deglutition responses indicate the possibility of impaired descending modulation and central malfunctions of brainstem and vagal nuclei.

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.

Feeding Difficulties in Preterm Infants

Preterm infants often display difficulty establishing oral feeding in the weeks following birth. This article aims to provide an overview of the literature investigating the development of feeding skills in preterm infants, as well as of interventions aimed at assisting preterm infants to develop their feeding skills. Available research suggests that preterm infants born at a lower gestational age and/or with a greater degree of morbidity are most at risk of early feeding difficulties. Respiratory disease was identified as a particular risk factor. Mechanisms for feeding difficulty identified in the literature include immature or dysfunctional sucking skills and poor suck–swallow–breath coordination. Available evidence provides some support for therapy interventions aimed at improving feeding skills, as well as the use of restricted milk flow to assist with maintaining appropriate ventilation during feeds. Further research is needed to confirm these findings, as well as to answer remaining clinical questions.

Impact of prematurity and co-morbidities on feeding milestones in neonates: a retrospective study

OBJECTIVE

Feeding problems are an important area of neonatal morbidity that requires attention. We defined the feeding milestones related to transition to per oral feeding among premature infants based on gestational (GA) and postmenstrual ages (PMA), and elucidated the co-morbidity variables affecting with these skills.

STUDY DESIGN

Feeding progress was tracked during the first hospitalization in a retrospective study involving 186 infants. We measured the age at acquisition of first feedings, maximum gavage feedings and maximum oral feedings. Resource usage measures included the total length of hospital stay (LOS), duration of gavage tube and duration of respiratory support. Effects of perinatal and co-morbidity factors on the acquisition of feeding milestones were evaluated. ANOVA, t-test, Wilcoxon rank sum test, chi(2) test, univariate and multivariate analysis, stepwise linear regression analysis and logistic regression analysis were applied as appropriate. Data were presented as mean+/-s.d., or as stated. P<0.05 was considered significant.

RESULT

We stratified the data into three groups based on GA at birth: <28.0 weeks (group-1), 28.0 to 32.0 weeks (group-2) and 32.0 to 35.0 weeks (group-3). Compared with group-3, group-1 needed four-fold more ventilation and five-fold more continuous positive airway pressure (CPAP) duration (all P<0.001); whereas group-2 needed two-fold more CPAP duration. Age at first feed correlated with age at full gavage feedings and age at full oral feedings (r=0.53 and r=0.71, both P<0.0001). Age at full gavage feedings correlated with age at full oral feedings (r=0.81, P<0.0001). Univariate analysis was significant for GA age, hypotension, the effects of gastroesophageal reflux, and duration of ventilation and CPAP on the PMA at maximal oral feedings (all P<0.05); multivariate analysis for these variables was also significant (R (2)=0.58, P<0.0001). The success rate for oral feedings at discharge accelerated with GA maturation and caffeine use; on the other hand, the need for respiratory support and management of positive blood culture were associated with failure rates (P<0.05).

CONCLUSION

Infants < 28 weeks GA have significant feeding delays with respect to initiation and progression to maximal gavage and oral feedings, as well as prolonged LOS. Infants >28 weeks GA attained successful feeding milestones by similar PMA. Specific aero-digestive co-morbidities significantly affected maximal oral feeding milestone. Delays in achieving maximum gavage and maximum oral feeding milestones suggest delays with the development of control and regulation of foregut motility.

The preterm piglet - a model in the study of oesophageal development in preterm neonates

AIM

Preterm infants have difficulty in attaining independent oral feeding. This can ensue from inadequate sucking, swallowing and/or respiration. In impeding bolus transport, immature oesophageal motility may also be a cause. As studies on the development of oesophageal motility are invasive in preterm infants, the preterm piglet was investigated as a potential research model.

METHODS

Oesophageal motility (EM) of term (n = 6) and preterm (n = 15) piglets were monitored by manometry for 10 min immediately following bottle feeding on days 1-2 and 3-4 of life.

RESULTS

Piglets' oral feeding performance and EM were similar to those of their human counterparts. Term piglets readily completed their feeding, whereas their preterm counterparts did not. They also presented with greater peristaltic activity and propagating velocity. Peristaltic activity remained unchanged over time in preterm piglets, but an increase in synchronous and decrease in incomplete motor activity were noted. Preterm piglets that developed symptoms analogous to necrotizing enterocolitis (NEC) demonstrated uncharacteristic oesophageal activity.

CONCLUSION

Immature EM may cause oral feeding difficulties. NEC-like symptoms may adversely affect EM. The piglet is a valid research model for studying human infant oral feeding and oesophageal development.

Feeding abilities in neonates with congenital heart disease: a retrospective study

OBJECTIVE

An important area concerning morbidity among infants with congenital heart defects (CHD) is related to feeding problems. Our objectives were to characterize the evolution of feeding milestones related to transition to per oral feeding among infants with CHD, and to identify associated variables impacting the feeding abilities. Specifically, we differentiated the feeding characteristics in neonates with acyanotic vs cyanotic CHD.

STUDY DESIGN

Feeding progress was tracked during the first hospitalization in a retrospective chart review study involving 76 infants (29 acyanotic, 47 cyanotic CHD). The ages at which the following milestones attained were recorded: first feeds, maximum gavage feeds, first nipple feeds and maximum nipple feeds, in addition to the length of hospital stay. Effects of perinatal factors, duration of respiratory support, vasopressor and narcotic use and use of cardiopulmonary bypass on the feeding milestones were also evaluated. ANOVA, t-test, and stepwise linear regression analysis were applied as appropriate. Data stated as mean+/-s.e.m., or %; P<0.05 was considered significant.

RESULT

Prenatal and birth characteristics were similar (P=NS) between the neonates with acyanotic and cyanotic CHD. Cyanotic CHD required three times prolonged use of ventilation, narcotics and vasopressor use (all P<0.05, compared to the acyanotic group). In the acyanotic group, prolonged respiratory support correlated linearly with time to attain maximal gavage feeds and nippling (both, R2=0.8). In the cyanotic group, delayed initiation of gavage feeds and prolonged respiratory support both correlated linearly with time to attain maximal gavage feeds and nippling (both, R2=0.8). Age at first gavage feed correlated with maximum gavage feeds among neonates with cyanotic CHD, and first nipple feed correlated with maximum nipple feeds among all groups (P<0.01). Use of cardiopulmonary bypass in cyanotic CHD delayed the feeding milestones and prolonged the length of stay (both, P<0.05 vs non-bypass group); similar findings were not seen in the acyanotic group.

CONCLUSION

In contrast to neonates with acyanotic CHD, cyanotic CHD group had significant delays with (a) feeding readiness, (b) successful gastric feeding, (c) oromotor readiness and (d) successful oromotor skills. Co-morbid factors that may directly influence the delay in feeding milestones include the (a) duration of respiratory support and (b) use of cardiopulmonary bypass. Delays in achieving maximum gavage and maximum nippling may suggest foregut dysmotility and oropharyngeal dysphagia.