Frequency-modulated orocutaneous stimulation promotes non-nutritive suck development in preterm infants with respiratory distress syndrome or chronic lung disease

Oral motor interventions used to support the development of oral feeding skills in preterm infants: An integrative review

BACKGROUND

One criterion for infant NICU discharge is the ability to meet all nutritional needs by mouth, therefore, it is important to understand interventions that can improve the trajectory to full oral feeding. While many oral motor and feeding interventions are used in clinical practice, it remains unclear which are supported by the literature.

AIM

The aim of this integrative review was to identify and understand what oral motor interventions are defined in the literature to support positive outcomes for preterm infants and their parents.

METHODS

An integrative review of studies published from 2002 to 2022 focusing on applied oral motor interventions and their impact on feeding-related outcomes was completed. The systematic search used databases including PubMed, Cochrane, CINAHL, Scopus, and Google Scholar. Studies were included if they used a study population of preterm infants born

RESULTS

Forty articles met inclusion criteria with four different interventions (or a combination of them) identified: nonnutritive sucking, oral motor stimulation [Fucile's protocol, Premature Infant Oral Motor Intervention (PIOMI)], NTrainer, and swallowing exercises.

DISCUSSION

All interventions were associated with positive outcomes and began between 29- and 30-weeks PMA. Detailed information on adverse events (both physiologic and behavioral) in future research could allow for better risk-benefit analysis. The methodology and quality of the studies differed too much to allow for quantitative analysis; however, there does not appear to be compelling evidence that more stimulatory interventions are superior to less stimulatory interventions - a key consideration when working with preterm infants.

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Key Words

• Feeding development
• Infants
• Oral motor intervention
• Preterm

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MESH Headings Collapse

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Affiliation(s)

Carolyn Ibrahim College of Health Sciences, Rush University, Chicago, IL, United States of America
Patricia Chavez Library of Rush University Medical Center, Chicago, IL, United States of America
Delaney Smith Chan Division of Occupational Science and Occupational Therapy, University of Southern California, Los Angeles, CA, United States of America
Jenene Craig School of Psychology, Infant and Early Childhood Development, Fielding Graduate University, Santa Barbara, CA, United States of America
Roberta Pineda Chan Division of Occupational Science and Occupational Therapy, University of Southern California, Los Angeles, CA, United States of America.

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Impact of volume and rate of milk delivery on coordination of respiration and swallowing in infant pigs

The coordination of respiration and swallowing is a life-critical function in infants. Varying volume and rate of milk delivery changes swallowing frequency and bolus volume but any impact on swallow-respiration coordination is unknown. Five infant pigs were filmed with simultaneous high speed videofluoroscopy and plethysmography while feeding from an automatic system delivering milk across a range of volumes and frequencies. Swallow inspiration delay, respiratory cycle duration, and distribution of inspiratory and expiratory swallows were calculated. At constant volume, there were more inspiratory phase swallows when frequency increased. At high constant frequency, increasing volume changed swallow-respiration coordination patterns, with increased occurrence of inspiratory phase swallows. Respiratory cycle duration did not change in response to changes in oral milk delivery. These results suggest that the observed pattern of expiratory swallowing in infants is achieved primarily by regulation of milk intake, not modulation of respiratory patterns by oral sensation.

Nipple properties affect sensorimotor integration during bottle feeding in an infant pig model

Infant feeding is a critical neurological milestone in development defined by the coordination of muscles, peripheral nerves, and brainstem nuclei. In infants, milk flow rate is often limited to improve feeding performance without treating the underlying deficiencies in the sucking and swallowing processes. Modification of the neuromotor response via sensory information from the nipple during bottle feeding is an unexplored avenue for physiology-based interventions. In this study, we assessed how differences in nipple hole size and nipple stiffness affect sucking muscle activation and subsequent movement. We fabricated four bottle nipples of varying hole size and stiffness to determine how variation in nipple properties affects the sucking behavior of infant pigs. Our results demonstrate that sensory information from the nipple affects sucking motor output. Nipple hole sizes and stiffnesses with a larger milk flow rate resulted in greater muscle activity and kinematic movement. Additionally, our results suggest that sensorimotor interventions are better directed toward modulating tongue function rather than the mandible movements due to a greater response to sensory information. Understanding how sensory information influences infant feeding is instrumental in promoting effective infant feeding.

Oral stimulation for promoting oral feeding in preterm infants

BACKGROUND

Preterm infants (< 37 weeks' post-menstrual age (PMA)) are often delayed in attaining oral feeding. Normal oral feeding is suggested as an important outcome for the timing of discharge from the hospital and can be an early indicator of neuromotor integrity and developmental outcomes. A range of oral stimulation interventions may help infants to develop sucking and oromotor co-ordination, promoting earlier oral feeding and earlier hospital discharge. This is an update of our 2016 review.

OBJECTIVES

To determine the effectiveness of oral stimulation interventions for attainment of oral feeding in preterm infants born before 37 weeks' PMA.

SEARCH METHODS

Searches were run in March 2022 of the following databases: CENTRAL via CRS Web; MEDLINE and Embase via Ovid. We also searched clinical trials databases and the reference lists of retrieved articles for randomised controlled trials (RCTs) and quasi-randomised trials. Searches were limited by date 2016 (the date of the search for the original review) forward. Note: Due to circumstances beyond our control (COVID and staffing shortages at the editorial base of Cochrane Neonatal), publication of this review, planned for mid 2021, was delayed. Thus, although searches were conducted in 2022 and results screened, potentially relevant studies found after September 2020 have been placed in the section, Awaiting Classification, and not incorporated into our analysis.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials comparing a defined oral stimulation intervention with no intervention, standard care, sham treatment or non-oral intervention (e.g. body stroking protocols or gavage adjustment protocols) in preterm infants and reporting at least one of the specified outcomes.

DATA COLLECTION AND ANALYSIS

Following the updated search, two review authors screened the titles and abstracts of studies and full-text copies when needed to identify trials for inclusion in the review. The primary outcomes of interest were time (days) to exclusive oral feeding, time (days) spent in NICU, total hospital stay (days), and duration (days) of parenteral nutrition. All review and support authors contributed to independent extraction of data and analysed assigned studies for risk of bias across the five domains of bias using the Cochrane Risk of Bias assessment tool. The GRADE system was used to rate the certainty of the evidence. Studies were divided into two groups for comparison: intervention versus standard care and intervention versus other non-oral or sham intervention. We performed meta-analysis using a fixed-effect model.

MAIN RESULTS

We included 28 RCTs (1831 participants). Most trials had methodological weaknesses, particularly in relation to allocation concealment and masking of study personnel. Oral stimulation compared with standard care Following meta-analysis, it is uncertain whether oral stimulation reduces the time to transition to oral feeding compared with standard care (mean difference (MD) -4.07 days, 95% confidence interval (CI) -4.81 to -3.32 days, 6 studies, 292 infants; I2 =85%, very low-certainty evidence due to serious risk of bias and inconsistency). Time (days) spent in the neonatal intensive care unit (NICU) was not reported. It is uncertain whether oral stimulation reduces the duration of hospitalisation (MD -4.33, 95% CI -5.97 to -2.68 days, 5 studies, 249 infants; i2 =68%, very low-certainty evidence due to serious risk of bias and inconsistency). Duration (days) of parenteral nutrition was not reported. Oral stimulation compared with non-oral intervention Following meta-analysis, it is uncertain whether oral stimulation reduces the time to transition to exclusive oral feeding compared with a non-oral intervention (MD -7.17, 95% CI -8.04 to -6.29 days, 10 studies, 574 infants; I2 =80%, very low-certainty evidence due to serious risk of bias, inconsistency and precision). Time (days) spent in the NICU was not reported. Oral stimulation may reduce the duration of hospitalisation (MD -6.15, 95% CI -8.63 to -3.66 days, 10 studies, 591 infants; I2 =0%, low-certainty evidence due to serious risk of bias). Oral stimulation may have little or no effect on the duration (days) of parenteral nutrition exposure (MD -2.85, 95% CI -6.13 to 0.42, 3 studies, 268 infants; very low-certainty evidence due to serious risk of bias, inconsistency and imprecision).

AUTHORS' CONCLUSIONS

There remains uncertainty about the effects of oral stimulation (versus either standard care or a non-oral intervention) on transition times to oral feeding, duration of intensive care stay, hospital stay, or exposure to parenteral nutrition for preterm infants. Although we identified 28 eligible trials in this review, only 18 provided data for meta-analyses. Methodological weaknesses, particularly in relation to allocation concealment and masking of study personnel and caregivers, inconsistency between trials in effect size estimates (heterogeneity), and imprecision of pooled estimates were the main reasons for assessing the evidence as low or very low certainty. More well-designed trials of oral stimulation interventions for preterm infants are warranted. Such trials should attempt to mask caregivers to treatment when possible, paying particular attention to blinding of outcome assessors. There are currently 32 ongoing trials. Outcome measures that reflect improvements in oral motor skill development as well as longer term outcome measures beyond six months of age need to be defined and used by researchers to capture the full impact of these interventions.

The effect of stiffness and hole size on nipple compression in infant suckling

During infant feeding, the nipple is an important source of sensory information that affects motor outputs, including ones dealing with compression of the nipple, suction, milk bolus movement, and swallowing. Despite known differences in behavior across commercially available nipples, little is known about the in vivo effects of nipple property variation. Here we quantify the effect of differences in nipple stiffness and hole size on an easily measured metric representing infant feeding behavior: nipple compression. We bottle-fed 7-day old infant pigs (n = 6) on four custom fabricated silicone nipples. We recorded live X-ray fluoroscopic imaging data of feeding on nipples of two levels of hardness/stiffness and two hole sizes. We tested for differences in nipple compression at the nipple's maximum compression across different nipple types using a mixed model analysis of variance. Stiffer nipples and those with smaller holes were compressed less than compliant nipples and nipples with larger holes (p < 0.001). We also estimated the force applied on the nipple during feeding and found that more force was applied to the compliant nipple with disproportionately larger strains. Our results suggest that infant pigs' nipple compression depends on material type and hole size, which is likely detected by the infant pigs' initial assessment of compressibility and flow. By isolating nipple properties, we demonstrated a relationship between properties and suckling behavior. Our results suggest that sensory information affects feeding behaviors and may also inform clinical treatment of poor feeding performance.

Predicting Feeding Conditions of Premature InfantsThrough Non-Nutritive Sucking Skills Using a Sensitized Pacifier

Due to the lack of enough physical or suck central pattern generator (SCPG) development, premature infants require assistance in improving their sucking skills as one of the first coordinated muscular activities in infants. Hence, we need to quantitatively measure their sucking abilities for future studies on their sucking interventions. Here, we present a new device that can measure both intraoral pressure (IP) and expression pressure (EP) as ororhithmic behavior parameters of non-nutritive sucking skills in infants. Our device is low-cost, easy-to-use, and accurate, which makes it appropriate for extensive studies. To showcase one of the applications of our device, we collected weekly data from 137 premature infants from 29 week-old to 36 week-old. Around half of the infants in our study needed intensive care even after they were 36 week-old. We call them full attainment of oral feeding (FAOF) infants. We then used the Non-nutritive sucking (NNS) features of EP and IP signals of infants recorded by our device to predict FAOF infants' sucking conditions. We found that our pipeline can predict FAOF infants several weeks before discharge from the hospital. Thus, this application of our device presents a robust and inexpensive alternative to monitor oral feeding ability in premature infants.

Oro-Motor Intervention Protocol to Improve Sucking Behavior among Neonates with Immature Sucking: An Experimental Protocol

Background:

Oro-motor intervention methods were previously adopted to improve the sucking pattern but there is still a lag in the structured protocol for improving sucking behavior in infants with immature sucking. Thus, this study is aimed to develop a structured protocol for the Oro-motor intervention to improve sucking behavior.

Method:

Using the prospective observational study design, neonates with poor suck (producing less than 10 sucks per minute), under NG tube feeding, and maintaining oxygen saturation at room air were included. A total of 6 subjects were enrolled in this study and they were treated with Oro-motor intervention protocol. The Sucking rate and LATCH score were taken as the outcome measures and measured at beginning of intervention and after 2 weeks of intervention.

Result:

The mean pre-test and post-test values for sucking rate were is (8.66), (32.5) and LATCH were (4.66), (8.16) respectively. The data collected showed that the protocol framed for Oro-motor intervention was significantly effective in improving quality of feeding among infants with immature sucking behavior.

Conclusion:

The structured Oro-motor intervention protocol improves the feeding performance in infants with poor sucking behavior and improves the LATCH score. All the infants included in this study where under nasogastric tube feeding, thus the structured protocol can be considered to be helpful in weaning from NG tube feeding.

Does birth weight affect neonatal body weight, growth, and physiology in an animal model?

Infant birth weight affects neuromotor and biomechanical swallowing performance in infant pig models. Preterm infants are generally born low birth weight and suffer from delayed development and neuromotor deficits. These deficits include critical life skills such as swallowing and breathing. It is unclear whether these neuromotor and biomechanical deficits are a result of low birth weight or preterm birth. In this study we ask: are preterm infants simply low birth weight infants or do preterm infants differ from term infants in weight gain and swallowing behaviors independent of birth weight? We use a validated infant pig model to show that preterm and term infants gain weight differently and that birth weight is not a strong predictor of functional deficits in preterm infant swallowing. We found that preterm infants gained weight at a faster rate than term infants and with nearly three times the variation. Additionally, we found that the number of sucks per swallow, swallow duration, and the delay of the swallows relative to the suck cycles were not impacted by birth weight. These results suggest that any correlation of developmental or swallowing deficits with reduced birth weight are likely linked to underlying physiological immaturity of the preterm infant.

Sucking versus swallowing coordination, integration, and performance in preterm and term infants

Mammalian infants must be able to integrate the acquisition, transport, and swallowing of food to effectively feed. Understanding how these processes are coordinated is critical, as they have differences in neural control and sensitivity to perturbation. Despite this, most studies of infant feeding focus on isolated processes, resulting in a limited understanding of the role of sensorimotor integration in the different processes involved in infant feeding. This is especially problematic in the context of preterm infants, as they are considered to have pathophysiological brain development and often experience feeding difficulties. Here, we use an animal model to study how the different properties of food acquisition, transport, and swallowing differ between term and preterm infants longitudinally through infancy to understand which processes are sensitive to variation in the bolus being swallowed. We found that term infants are better able to acquire milk than preterm infants, and that properties of acquisition are strongly correlated with the size of the bolus being swallowed. In contrast, behaviors occurring during the pharyngeal swallow, such as hyoid and soft palate movements, show little to no correlation with bolus size. These results highlight the pathophysiological nature of the preterm brain and also demonstrate that behaviors occurring during oral transport are much more likely to respond to sensory intervention than those occurring during the "pharyngeal phase."NEW & NOTEWORTHY Physiological maturation of infant feeding is clinically and developmentally significant, but seldom examined as an integrated function. Using longitudinal high-speed videofluoroscopic data, we found that properties of sucking, such as the length of the suck, are more sensitive to swallow physiology than those associated with the pharyngeal swallow itself, such as hyoid excursion. Prematurity impacted the function and maturation of the feeding system, resulting in a physiology that fundamentally differs from term infants by weaning.

Preterm Birth Impacts the Timing and Excursion of Oropharyngeal Structures during Infant Feeding

Swallowing in mammals requires the precise coordination of multiple oropharyngeal structures, including the palatopharyngeal arch. During a typical swallow, the activity of the palatopharyngeus muscle produces pharyngeal shortening to assist in producing pressure required to swallow and may initiate epiglottal flipping to protect the airway. Most research on the role of the palatopharyngeal arch in swallowing has used pharyngeal manometry, which measures the relative pressures in the oropharynx, but does not quantify the movements of the structures involved in swallowing. In this study, we assessed palatopharyngeal arch and soft palate function by comparing their movements in a healthy population to a pathophysiological population longitudinally through infancy (term versus preterm pigs). In doing so, we test the impact of birth status, postnatal maturation, and their interaction on swallowing. We tracked the three-dimensional (3D) movements of radiopaque beads implanted into relevant anatomical structures and recorded feeding via biplanar high-speed videofluoroscopy. We then calculated the total 3D excursion of the arch and soft palate, the orientation of arch movement, and the timing of maximal arch constriction during each swallow. Soft palate excursion was greater in term infants at both 7 and 17 days postnatal, whereas arch excursion was largely unaffected by birth status. Maximal arch constriction occurred much earlier in preterm pigs relative to term pigs, a result that was consistent across age. There was no effect of postnatal age on arch or soft palate excursion. Preterm and term infants differed in their orientation of arch movement, which most likely reflects both differences in anatomy and differences in feeding posture. Our results suggest that the timing and coordination of oropharyngeal movements may be more important to feeding performance than the movements of isolated structures, and that differences in the neural control of swallowing and its maturation in preterm and term infants may explain preterm swallowing deficits.

Physiological Basis of Neonatal Aerodigestive Difficulties in Chronic Lung Disease

In the United States, preterm birth rates have steadily increased since 2014. Despite the recent advances in neonatal-perinatal care, more than 40% of very low-birth-weight infants develop chronic lung disease (CLD) and almost 25% have feeding difficulties resulting in delayed achievement of full oral feeds and longer hospital stay. Establishment of full oral feeds, a major challenge for preterm infants, becomes magnified among those on respiratory support and/or with CLD. The strategies to minimize aerodigestive disorders include supporting nonnutritive sucking, developing infant-directed feeding protocols, sensory oromotor stimulation, and early introduction of oral feeds.

Feeding and Swallowing Difficulties in Neonates: Developmental Physiology and Pathophysiology

Development of enteral and oral feeding milestones in infants is intricately linked to physiologic maturation of the gastrointestinal tract and its complex interplay with cardiorespiratory and central nervous system control and coordination. Assessment of an infant's developmental skills and maturation can guide us with targeted management approaches and prediction of feeding outcomes. In this article, we review and summarize the developmental aspects of oral feeding and swallowing physiology, and current understanding of the pathophysiological changes associated with feeding difficulties in infants.

Reduced Coordination of Hyolaryngeal Elevation and Bolus Movement in a Pig Model of Preterm Infant Swallowing

Preterm infants often have dysphagia. Because reducing lifetime cumulative exposure to radiation in the context of diagnosis and treatment is a continuing goal of all medical fields which use X-ray imaging, efforts exist to reduce reliance on the gold standard diagnostic tool for dysphagia, VFSS. Alternatives, such as video of external hyolaryngeal movement using video recordings of the anterior surface of the neck, must be evaluated and validated against videofluoroscopy, a task for which non-human animal models are appropriate. In this study, we tested the hypotheses that (1) swallows could be identified equally well from video of external hyolaryngeal movement and bolus movement in videofluoroscopy, and that (2) the two measures would be tightly temporally linked in both term and preterm infant pigs. We recorded 222 swallows in simultaneous and precisely synchronized high-speed videofluoroscopy and high-speed camera films of 4 preterm and 3 term infant pigs drinking milk from a bottle. In term pigs, the two measures consistently identified the same swallows in each image stream. However, in preterm pigs there was a high rate of false positives (~ 10% per feeding sequence) and false negatives (~ 27% per feeding sequence). The timing of hyolaryngeal elevation (external video) and bolus movement (videofluoroscopy) was correlated and consistent in terms pigs, but not in preterm pigs. Magnitude of hyolaryngeal elevation was less in preterm pig swallows than term pig swallows. Absence of epiglottal inversion in preterm pigs was not linked to variation in the timing of the two swallow events. Video of external hyolaryngeal movement, though a reliable swallow indicator in term infant pigs, was unreliable in preterm infant pigs. The coordination of swallowing events differs in preterm and term infant pigs. More research is needed into the distinctive biomechanics of preterm infant pigs.

Early Intervention to Improve Sucking in Preterm Newborns: A Systematic Review of Quantitative Studies

BACKGROUND

Premature birth is associated with feeding difficulties due to inadequate coordination of sucking, swallowing, and breathing. Nonnutritive sucking (NNS) and oral stimulation interventions may be effective for oral feeding promotion, but the mechanisms of the intervention effects need further clarifications.

PURPOSE

We reviewed preterm infant intervention studies with quantitative outcomes of sucking performance to summarize the evidence of the effect of interventions on specific components of sucking.

METHODS

PubMed, CINAHL, MEDLINE, EMBASE, and PSYCOLIST databases were searched for English language publications through August 2017. Studies were selected if they involved preterm infants, tested experimental interventions to improve sucking or oral feeding skills, and included outcome as an objective measure of sucking performance. Specific Medical Subject Headings (MeSH) terms were utilized.

RESULTS

Nineteen studies were included in this review: 15 randomized, 1 quasi-randomized, and 3 crossover randomized controlled trials. Intervention types were grouped into 6 categories (i) NNS, (ii) NNS with auditory reinforcement, (iii) sensorimotor stimulation, (iv) oral support, (v) combined training, and (vi) nutritive sucking. Efficiency parameters were positively influenced by most types of interventions, though appear to be less affected by trainings based on NNS alone.

IMPLICATIONS FOR PRACTICE

These findings may be useful in the clinical care of infants requiring support to achieve efficient sucking skills through NNS and oral stimulation interventions.

IMPLICATIONS FOR RESEARCH

Further studies including quantitative measures of sucking performance outcome measures are needed in order to best understand the needs and provide more tailored interventions to preterm infants.

Patterned frequency-modulated oral stimulation in preterm infants: A multicenter randomized controlled trial

Objective

To evaluate the effect of patterned, frequency-modulated oro-somatosensory stimulation on time to full oral feeds in preterm infants born 26–30 weeks gestation.

Study design

This is a multicenter randomized controlled trial. The experimental group (n = 109) received patterned, frequency-modulated oral stimulation via the NTrainer system through a pulsatile pacifier and the control group (n = 101) received a non-pulsatile pacifier. Intent-to-treat analysis (n = 210) was performed to compare the experimental and control groups and the outcomes were analyzed using generalized estimating equations. Time-to-event analyses for time to reach full oral feeds and length of hospital stay were conducted using Cox proportional hazards models.

Results

The experimental group had reduction in time to full oral feeds compared to the control group (-4.1 days, HR 1.37 (1.03, 1.82) p = 0.03). In the 29–30 weeks subgroup, infants in the experimental group had a significant reduction in time to discharge (-10 days, HR 1.87 (1.23, 2.84) p < 0.01). This difference was not observed in the 26–28 weeks subgroup. There was no difference in growth, mortality or morbidities between the two groups.

Conclusions

Patterned, frequency-modulated oro-somatosensory stimulation improves feeding development in premature infants and reduces their length of hospitalization.

Trial registration

ClinicalTrials.gov NCT01158391

Automatic Nonnutritive Suck Waveform Discrimination and Feature Extraction in Preterm Infants

Background and Objective: The emergence of the nonnutritive suck (NNS) pattern in preterm infants reflects the integrity of the brain and is used by clinicians in the neonatal intensive care unit (NICU) to assess feeding readiness and oromotor development. A critical need exists for an integrated software platform that provides NNS signal preprocessing, adaptive waveform discrimination, feature detection, and batch processing of big data sets across multiple NICU sites. Thus, the goal was to develop and describe a cross-platform graphical user interface (GUI) and terminal application known as NeoNNS for single and batch file time series and frequency-domain analyses of NNS compression pressure waveforms using analysis parameters derived from previous research on NNS dynamics. Methods. NeoNNS was implemented with Python and the Tkinter GUI package. The NNS signal-processing pipeline included a low-pass filter, asymmetric regression baseline correction, NNS peak detection, and NNS burst classification. Data visualizations and parametric analyses included time- and frequency-domain view, NNS spatiotemporal index view, and feature cluster analysis to model oral feeding readiness. Results. 568 suck assessment files sampled from 30 extremely preterm infants were processed in the batch mode (<50 minutes) to generate time- and frequency-domain analyses of infant NNS pressure waveform data. NNS cycle discrimination and NNS burst classification yield quantification of NNS waveform features as a function of postmenstrual age. Hierarchical cluster analysis (based on the Tsfresh python package and NeoNNS) revealed the capability to label NNS records for feeding readiness. Conclusions. NeoNNS provides a versatile software platform to rapidly quantify the dynamics of NNS development in time and frequency domains at cribside over repeated sessions for an individual baby or among large numbers of preterm infants at multiple hospital sites to support big data analytics. The hierarchical cluster feature analysis facilitates modeling of feeding readiness based on quantitative features of the NNS compression pressure waveform.

Preterm Neurodevelopmental Outcomes Following Orosensory Entrainment Intervention

Previous research indicates that the NTrainer, a pressurized pacifier programmed to produce pulsed pneumotactile stimulation during gavage feeds, has been found to facilitate non-nutritive suck development and shorten the length of hospital stay when used in the Neonatal Intensive Care Unit (NICU). Four groups of children, including infants of diabetic mothers (IDM), healthy controls (HI), and those with respiratory distress syndrome (RDS), or chronic lung disease (CLD), were randomly assigned to an NTrainer therapy or sham 'control' condition when in the NICU. At 30 months of age, 113/223 study participants were assessed using standardized language, motor, and cognitive assessments. No significant group differences were evident between the NTrainer and sham groups in language, motor, or cognitive functioning. The NTrainer did not improve nor adversely impact language, cognition, or motor outcomes.

Feeding Disorders

Feeding disorders often present in children with complex medical histories as well as those with neurodevelopmental disabilities. If untreated, feeding problems will likely persist and may lead to additional developmental and medical complications. Treatment of pediatric feeding disorders should involve an interdisciplinary team, but the core intervention should include behavioral feeding techniques as they are the only empirically supported therapy for feeding disorders.

Somatosensory Modulation of Salivary Gene Expression and Oral Feeding in Preterm Infants: Randomized Controlled Trial

BACKGROUND

Despite numerous medical advances in the care of at-risk preterm neonates, oral feeding still represents one of the first and most advanced neurological challenges facing this delicate population. Objective, quantitative, and noninvasive assessment tools, as well as neurotherapeutic strategies, are greatly needed in order to improve feeding and developmental outcomes. Pulsed pneumatic orocutaneous stimulation has been shown to improve nonnutritive sucking (NNS) skills in preterm infants who exhibit delayed or disordered nipple feeding behaviors. Separately, the study of the salivary transcriptome in neonates has helped identify biomarkers directly linked to successful neonatal oral feeding behavior. The combination of noninvasive treatment strategies and transcriptomic analysis represents an integrative approach to oral feeding in which rapid technological advances and personalized transcriptomics can safely and noninvasively be brought to the bedside to inform medical care decisions and improve care and outcomes.

OBJECTIVE

The study aimed to conduct a multicenter randomized control trial (RCT) to combine molecular and behavioral methods in an experimental conceptualization approach to map the effects of PULSED somatosensory stimulation on salivary gene expression in the context of the acquisition of oral feeding habits in high-risk human neonates. The aims of this study represent the first attempt to combine noninvasive treatment strategies and transcriptomic assessments of high-risk extremely preterm infants (EPI) to (1) improve oral feeding behavior and skills, (2) further our understanding of the gene ontology of biologically diverse pathways related to oral feeding, (3) use gene expression data to personalize neonatal care and individualize treatment strategies and timing interventions, and (4) improve long-term developmental outcomes.

METHODS

A total of 180 extremely preterm infants from three neonatal intensive care units (NICUs) will be randomized to receive either PULSED or SHAM (non-pulsing) orocutaneous intervention simultaneous with tube feedings 3 times per day for 4 weeks, beginning at 30 weeks postconceptional age. Infants will also be assessed 3 times per week for NNS performance, and multiple saliva samples will be obtained each week for transcriptomic analysis, until infants have achieved full oral feeding status. At 18 months corrected age (CA), infants will undergo neurodevelopmental follow-up testing, the results of which will be correlated with feeding outcomes in the neo-and post-natal period and with gene expression data and intervention status.

RESULTS

The ongoing National Institutes of Health funded randomized controlled trial R01HD086088 is actively recruiting participants. The expected completion date of the study is 2021.

CONCLUSIONS

Differential salivary gene expression profiles in response to orosensory entrainment intervention are expected to lead to the development of individualized interventions for the diagnosis and management of oral feeding in preterm infants.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02696343; https://clinicaltrials.gov/ct2/show/NCT02696343 (Archived by WebCite at http://www.webcitation.org/6r5NbJ9Ym).

Patterned auditory stimulation and suck dynamics in full-term infants

AIM

To determine whether patterned auditory stimuli, designed to mimic the natural burst-pause pattern evident in non-nutritive suck (NNS) with variations to the intraburst frequency, alter infants' NNS and cardiorespiratory patterning.

METHODS

Sixteen healthy full-term infants participated in this study. Infants were fitted with electrocardiogram electrodes and a respiratory belt to measure cardiorespiratory patterning. Infants were offered a custom pacifier attached to a pressure transducer to measure NNS. Prior to the start of the study, a two-minute NNS and cardiorespiratory baseline was attained. Next, three auditory stimulation conditions were presented in the form of sucking clicks at interburst frequencies of 1, 2 and 4 Hz. Each of the three frequencies was played for two minutes.

RESULTS

Separate repeated-measures ANOVAs revealed significant differences in NNS burst duration (p = 0.013), NNS cycles/burst (p = 0.010) and NNS bursts/minute (p = 0.005) across auditory stimulation conditions. No significant differences were evident in the cardiorespiratory outcomes.

CONCLUSION

We found that patterned auditory stimulation significantly reduced NNS dynamics and had no effect on cardiorespiratory patterning. The findings further suggest that infants attempted to modulate their suck pattern to the patterned acoustic stimuli by shortening their burst durations with fewer cycles per burst.

Oral stimulation for promoting oral feeding in preterm infants

BACKGROUND

Preterm infants (< 37 weeks' postmenstrual age) are often delayed in attaining oral feeding. Normal oral feeding is suggested as an important outcome for the timing of discharge from the hospital and can be an early indicator of neuromotor integrity and developmental outcomes. A range of oral stimulation interventions may help infants to develop sucking and oromotor co-ordination, promoting earlier oral feeding and earlier hospital discharge.

OBJECTIVES

To determine the effectiveness of oral stimulation interventions for attainment of oral feeding in preterm infants born before 37 weeks' postmenstrual age (PMA).To conduct subgroup analyses for the following prespecified subgroups.• Extremely preterm infants born at < 28 weeks' PMA.• Very preterm infants born from 28 to < 32 weeks' PMA.• Infants breast-fed exclusively.• Infants bottle-fed exclusively.• Infants who were both breast-fed and bottle-fed.

SEARCH METHODS

We used the standard search strategy of the Cochrane Neonatal Review Group to search the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE via PubMed (1966 to 25 February 2016), Embase (1980 to 25 February 2016) and the Cumulative Index to Nursing and Allied Health Literature (CINAHL; 1982 to 25 February 2016). We searched clinical trials databases, conference proceedings and the reference lists of retrieved articles.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials comparing a defined oral stimulation intervention with no intervention, standard care, sham treatment or non-oral intervention in preterm infants and reporting at least one of the specified outcomes.

DATA COLLECTION AND ANALYSIS

One review author searched the databases and identified studies for screening. Two review authors screened the abstracts of these studies and full-text copies when needed to identify trials for inclusion in the review. All review authors independently extracted the data and analysed each study for risk of bias across the five domains of bias. All review authors discussed and analysed the data and used the GRADE system to rate the quality of the evidence. Review authors divided studies into two groups for comparison: intervention versus standard care and intervention versus other non-oral or sham intervention. We performed meta-analysis using a fixed-effect model.

MAIN RESULTS

This review included 19 randomised trials with a total of 823 participants. Almost all included trials had several methodological weaknesses. Meta-analysis showed that oral stimulation reduced the time to transition to oral feeding compared with standard care (mean difference (MD) -4.81, 95% confidence interval (CI) -5.56 to -4.06 days) and compared with another non-oral intervention (MD -9.01, 95% CI -10.30 to -7.71 days), as well as the duration of initial hospitalisation compared with standard care (MD -5.26, 95% CI -7.34 to -3.19 days) and compared with another non-oral intervention (MD -9.01, 95% CI -10.30 to -7.71 days).Investigators reported shorter duration of parenteral nutrition for infants compared with standard care (MD -5.30, 95% CI -9.73 to -0.87 days) and compared with another non-oral intervention (MD -8.70, 95% CI -15.46 to -1.94 days). They could identify no effect on breast-feeding outcomes nor on weight gain.

AUTHORS' CONCLUSIONS

Although the included studies suggest that oral stimulation shortens hospital stay, days to exclusive oral feeding and duration of parenteral nutrition, one must interpret results of these studies with caution, as risk of bias and poor methodological quality are high overall. Well-designed trials of oral stimulation interventions for preterm infants are warranted. Such trials should use reliable methods of randomisation while concealing treatment allocation, blinding caregivers to treatment when possible and paying particular attention to blinding of outcome assessors.

Effects of pacifier and taste on swallowing, esophageal motility, transit, and respiratory rhythm in human neonates

BACKGROUND

Pacifier use is widely prevalent globally despite hygienic concerns and uncertain mechanistic effects on swallowing or airway safety.

AIMS

The effects of pacifier and taste interventions on pharyngo-esophageal motility, bolus transit, and respiratory rhythms were investigated by determining the upper esophageal sphincter (UES), esophageal body, esophagogastric junction (EGJ) motor patterns and deglutition apnea, respiratory rhythm disturbances, and esophageal bolus clearance.

METHODS

Fifteen infants (six males; median gestation 31 weeks and birth weight 1.4 kg) underwent high-resolution impedance manometry at 43 (41-44) weeks postmenstrual age. Manometric, respiratory, and impedance characteristics of spontaneous swallows, pacifier-associated dry swallowing and taste (pacifier dipped in 3% sucrose)-associated swallowing were analyzed. Linear mixed and generalized estimating equation models were used. Data are presented as mean ± SEM, %, or median (IQR).

KEY RESULTS

Pharyngo-esophageal motility, respiratory, and impedance characteristics of 209 swallows were analyzed (85 spontaneous swallows, 63 pacifier- swallows, 61 taste- swallows). Basal UES and EGJ pressures decreased upon pacifier (p < 0.05) and taste interventions (p < 0.05); however, esophageal motility, respiratory rhythm, and impedance transit characteristics were similar with both interventions.

CONCLUSIONS & INFERENCES

Oral stimulus with pacifier or taste interventions decreases UES and EGJ basal pressure, but has no effects on pharyngo-esophageal motility, airway interactions, or esophageal bolus transit. A decrease in central parasympathetic-cholinergic excitatory drive is likely responsible for the basal effects.

Adaptation of the cortical somatosensory evoked potential following pulsed pneumatic stimulation of the lower face in adults

Cortical adaptation to sustained sensory input is a pervasive form of short-term plasticity in neurological systems. Its role in sensory perception in health and disease, or predicting long-term plastic changes resulting from sensory training offers insight into the mechanisms of somatosensory and sensorimotor processing. A 4-channel electroencephalography (EEG) recording montage was placed bilaterally (C3-P3, C4-P4, F7-P3, F8-P4) to characterize the short-term effects of pulsed pneumatic orofacial stimulation on the cortical somatosensory evoked potential (cSEP) in twenty neurotypical adults (mean age=21±2.88 years). A servo-controlled pneumatic amplifier was used to deliver a repetitive series of pneumatic pulse trains (six 50-ms pulses, 5-second intertrain interval) through a linked pair of custom acetal homopolymer probes (aka TAC-Cells) adhered to the nonglabrous skin of the lower face proximal to the right oral angle to synchronously activate mechanoreceptive afferents in the trigeminal nerve. Blocks of pulse trains were counterbalanced among participants and delivered at two rates, 2 and 4Hz. TAC-Cell stimulation of the lower face consistently evoked a series of cSEPs at P7, N20, P28, N38, P75, N85, and P115. The spatial organization and adaptation of the evoked cSEP was dependent on stimulus pulse index (1-6 within the pulse train, p=.012), frequency of stimulus presentation (2 vs 4Hz, p<.001), component (P7-P115, p<.001), and recording montage (channels 1-4, p<.001). Early component latencies (P7-N20) were highly stable in polarity (sign) and latency, and consistent with putative far-field generators (e.g., trigeminal brainstem, ventroposteromedial thalamus).

The Effects of Non-Nutritive Sucking and Pre-Feeding Oral Stimulation on Time to Achieve Independent Oral Feeding for Preterm Infants

Background:

The survival rates of preterm infants has increased over the last years, but oral feeding difficulties are the most common problems encountered by them

Objectives:

This study aimed at comparing the effects of non-nutritive sucking (NNS) and pre-feeding oral stimulation on feeding skills, length of hospital stay and weight gain of 26-32 weeks gestational age preterm infants in NICU, to determine the more effective intervention.

Patients and Methods:

Thirty-two preterm infants were assigned randomly into three groups. One intervention group received pre-feeding oral stimulation program and the other received non-nutritive sucking stimulation, while the control group received a sham intervention. Gestational age of infants was calculated during 1, 4 and 8 oral feeding and discharge time from NICU. The infants’ weights were measured weekly from birth and at discharge time.

Results:

Mean gestational age on 8 time oral feeding per day, in 3 groups was not significant (P = 0.282). Although NNS and pre-feeding oral stimulation groups has fulfilled this criterion 7.55 and 6.07 days sooner than the control group, respectively (a result which is of great clinical and economic importance), but the difference did not reach statistical significance. Weight gaining at discharge time in NNS group was significantly higher than control and pre-feeding oral stimulation groups (P < 0.05).

Conclusions:

This study revealed that pre-feeding oral stimulation and NNS programs both were effective on oral feeding skills and weight gaining of the immature newborns. Yet, it seems that NNS program was more effective than pre-feeding oral stimulation on weight gaining.

Amplitude-integrated EEG and range-EEG modulation associated with pneumatic orocutaneous stimulation in preterm infants

OBJECTIVE

Controlled somatosensory stimulation strategies have demonstrated merit in developing oral feeding skills in premature infants who lack a functional suck, however, the effects of orosensory entrainment stimulation on electrocortical dynamics is unknown. The objective of the study was to determine the effects of servo-controlled pneumatic orocutaneous stimulation presented during gavage feedings on the modulation of amplitude-integrated electroencephalogram (aEEG) and range electroencephalogram (rEEG) activity.

STUDY DESIGN

Two-channel EEG recordings were collected during 180 sessions that included orocutaneous stimulation and non-stimulation epochs among 22 preterm infants (mean gestational age=28.56 weeks) who were randomized to treatment and control 'sham' conditions. The study was initiated at around 32 weeks post-menstrual age. The raw EEG was transformed into aEEG margins, and rEEG amplitude bands measured at 1-min intervals and subjected to a mixed models statistical analysis.

RESULT

Multiple significant effects were observed in the processed EEG during and immediately following 3-min periods of orocutaneous stimulation, including modulation of the upper and lower margins of the aEEG, and a reorganization of rEEG with an apparent shift from amplitude bands D and E to band C throughout the 23-min recording period that followed the first stimulus block when compared with the sham condition. Cortical asymmetry also was apparent in both EEG measures.

CONCLUSION

Orocutaneous stimulation represents a salient trigeminal input, which has both short- and long-term effects in modulating electrocortical activity, and thus is hypothesized to represent a form of neural adaptation or plasticity that may benefit the preterm infant during this critical period of brain maturation.