Recording non-nutritive sucking in the neonate. Description of an automatized system for analysis

Characterization of parameters for the analysis of objective measures of non-nutritive sucking of newborns

PURPOSE

To propose a methodology for analyzing data generated by an instrument measuring non-nutritive sucking pressure in newborns.

METHODS

An analytical observational study was developed, with a cross-sectional design, considering the data collected from 24 full-term newborns without complications. Three collections from each neonate were analyzed, with duration of 2 minutes and a 2-minute interval between them. The defined parameters were extracted using a program developed in Matlab®. The results were obtained by analyzing and comparing 12 variables at a 5% confidence level. Comparison of manual and computerized analyzes was also carried out using the intraclass correlation coefficient.

RESULTS

The multiple comparison between the three collection moments showed that the significant statistical differences occurred between collections one and two and two and three. When analyzing and comparing each variable separately, it was noted that the second collection showed: greater number of sucking groups, greater number of suctions, less time to start the sucking groups, longer time of sucking groups, less number of sporadic suctions, higher mean pressure values and with less standard deviation, more number of pauses with shorter time of pauses. The intraclass correlation coefficient revealed almost perfect agreement for the 12 evaluated parameters.

CONCLUSION

The 12 variables analyzed are relevant, especially in the second collection. The Matlab® program proved to be viable and effective in extracting and analyzing parameters, showing high agreement when compared to manual evaluation.

Non-Nutritive Suckling System for Real-Time Characterization of Intraoral Vacuum Profile in Full Term Neonates

Infant breastfeeding diagnostics remain subjective due to the absence of instrumentation to objectively measure and understand infant oral motor skills and suckling characteristics. Qualitative diagnostic exams, such as the digital suck assessment which relies upon a clinician's gloved finger inserted into the infant's mouth, produce a diversity of diagnoses and intervention pathways due to their subjective nature. In this paper, we report on the design of a non-nutritive suckling (NNS) system which quantifies and analyzes quantitative intraoral vacuum and sucking patterns of full-term neonates in real time. In our study, we evaluate thirty neonate suckling profiles to demonstrate the technical and clinical feasibility of the system. We successfully extract the mean suck vacuum, maximum suck vacuum, frequency, burst duration, number of sucks per burst, number of sucks per minute, and number of bursts per minute. In addition, we highlight the discovery of three intraoral vacuum profile shapes that are found to be correlated to different levels of suckling characteristics. These results establish a framework for future studies to evaluate oromotor dysfunction that affect the appearance of these signals based on established normal profiles. Ultimately, with the ability to easily and quickly capture intraoral vacuum data, clinicians can more accurately perform suckling assessments to provide timely intervention and assist mothers and infants towards successful breastfeeding outcomes.

Non-nutritive sucking milestones of preterm infants in Indonesia: a descriptive study

Background Non-nutritive sucking (NNS) maturity has been used as one of the markers of oral feeding readiness in infants. Prematurity may hinder the attainment of NNS milestones. Depending on gestational age (GA) at birth, preterm infants may display various degrees of immaturity, potentially affecting the strength, coordination, and efficiency of skills required for NNS. Objective To identify the progression of NNS patterns across gestational age groups of preterm infants in Indonesia by comparing NNS parameters between moderate-to-late preterm and very preterm infants. Methods NNS evaluation was conducted in 120 preterm infants born at 28-34 weeks gestational age in five tertiary hospitals in Jakarta, Indonesia. Three aspects of NNS (suction pressure, number of suctions per burst, and time between bursts) were documented and arranged to present a descriptive overview. A suction pressure measurement device was used to record, identify, and analyze NNS parameters. We hypothesize that maturity, as determined by GA, positively affected the attainment of NNS milestones. Results Moderate-to-late preterm infants (GA 32 to <37 weeks), compared to very preterm infants (GA 28 to <32 weeks), had higher mean NNS pressure (-79.8 vs. -72.7 mmHg, respectively, P=0.041) and shorter mean time between bursts (6.63 vs. 7.36 s, respectively, P=0.030). Mean number of suctions per burst were also significantly different between the two GA groups (8.90 vs. 8.99 sucks/burst, respectively, P=0.048). Conclusion Maturity, as reflected by GA, had a positive effect on the attainment of NNS milestones in preterm infants in Indonesia. Significant differences in the three NNS parameters: number of suctions per burst, time between bursts, and suction pressure were found between moderate-to-late preterm and very preterm infants.

Towards Continuous Camera-Based Respiration Monitoring in Infants

Aiming at continuous unobtrusive respiration monitoring, motion robustness is paramount. However, some types of motion can completely hide the respiration information and the detection of these events is required to avoid incorrect rate estimations. Therefore, this work proposes a motion detector optimized to specifically detect severe motion of infants combined with a respiration rate detection strategy based on automatic pixels selection, which proved to be robust to motion of the infants involving head and limbs. A dataset including both thermal and RGB (Red Green Blue) videos was used amounting to a total of 43 h acquired on 17 infants. The method was successfully applied to both RGB and thermal videos and compared to the chest impedance signal. The Mean Absolute Error (MAE) in segments where some motion is present was 1.16 and 1.97 breaths/min higher than the MAE in the ideal moments where the infants were still for testing and validation set, respectively. Overall, the average MAE on the testing and validation set are 3.31 breaths/min and 5.36 breaths/min, using 64.00% and 69.65% of the included video segments (segments containing events such as interventions were excluded based on a manual annotation), respectively. Moreover, we highlight challenges that need to be overcome for continuous camera-based respiration monitoring. The method can be applied to different camera modalities, does not require skin visibility, and is robust to some motion of the infants.

Abnormal Nutritive Sucking as an Indicator of Neonatal Brain Injury

A term neonate is born with the ability to suck; this neuronal network is already formed and functional by 28 weeks gestational age and continues to evolve into adulthood. Because of the necessity of acquiring nutrition, the complexity of the neuronal network needed to suck, and neuroplasticity in infancy, the skill of sucking has the unique ability to give insight into areas of the brain that may be damaged either during or before birth. Interpretation of the behaviors during sucking shows promise in guiding therapies and how to potentially repair the damage early in life, when neuroplasticity is high. Sucking requires coordinated suck-swallow-breathe actions and is classified into two basic types, nutritive and non-nutritive. Each type of suck has particular characteristics that can be measured and used to learn about the infant's neuronal circuitry. Basic sucking and swallowing are present in embryos and further develop to incorporate breathing ex utero. Due to the rhythmic nature of the suck-swallow-breathe process, these motor functions are controlled by central pattern generators. The coordination of swallowing, breathing, and sucking is an enormously complex sensorimotor process. Because of this complexity, brain injury before birth can have an effect on these sucking patterns. Clinical assessments allow evaluators to score the oral-motor pattern, however, they remain ultimately subjective. Thus, clinicians are in need of objective measures to identify the specific area of deficit in the sucking pattern of each infant to tailor therapies to their specific needs. Therapeutic approaches involve pacifiers, cheek/chin support, tactile, oral kinesthetic, auditory, vestibular, and/or visual sensorimotor inputs. These therapies are performed to train the infant to suck appropriately using these subjective assessments along with the experience of the therapist (usually a speech therapist), but newer, more objective measures are coming along. Recent studies have correlated pathological sucking patterns with neuroimaging data to get a map of the affected brain regions to better inform therapies. The purpose of this review is to provide a broad scope synopsis of the research field of infant nutritive and non-nutritive feeding, their underlying neurophysiology, and relationship of abnormal activity with brain injury in preterm and term infants.

Development of a technique for evaluating temporal parameters of sucking in breastfeeding preterm newborns

AIMS

The aim of the current study was to developed and test the reliability of a technique for measuring temporal parameters of sucking in breastfeeding infants.

METHODS

The technique was developed using a cohort of 11 term and 12 preterm infants, and subsequently evaluated using a cohort of 43 preterm infants. Measurements related to sucking pressure in the term and preterm infants were acquired. The signals were recorded for 5 min, saved on a computer, and stored for analysis. For purposes of analysis, the minute with the highest quality signal was chosen. Signal analysis was performed by two researchers, and inter- and intra-observer agreement was assessed. The newborns in the sample had different gestational ages.

RESULTS

A technique was developed for the analysis of temporal parameters of sucking during breastfeeding and evaluated in 43 preterm infants with different gestational ages for the following variables: number of bursts per minute, number of sucks per burst, sucking rate, pause rate, and duration of pauses. The intra-observer agreement was 0.85 and the inter-observer agreement was 0.85.

CONCLUSIONS

The technique that was developed and validated proved capable of measuring temporal parameters of sucking in breastfeeding newborns.

Breast milk odor via olfactometer for tube-fed, premature infants

Human newborns use odor cues to orient to their source of nutrition. However, tube-fed, premature infants have restricted chemosensory experience. New methods of introducing breast milk odor to tube-fed premature infants will permit empiric tests of the effect of controlled exposure to nutrient odor. We therefore developed an infant olfactometer and piloted its use in 7 tube-fed, premature infants in the neonatal intensive care unit. Since nonnutritive sucking shortens the amount of time required to wean from tube-feeding, we tested the effect of breast milk odor on nonnutritive sucking. Six out of 7 subjects responded to breast milk odor with an increase in number of sucks. Statistical analysis supported the hypothesis that breast milk odor reinforces nonnutritive sucking. These results indicate the feasibility and potential of this experimental approach, and warrant further study of the effect of controlled nutrient odor exposure on feeding behavior of premature infants.

Regional neonatal oral feeding protocol: changing the ethos of feeding preterm infants

The Calgary Health Region Neonatal Oral Feeding Protocol is the culminating work of a broad range of healthcare professionals, including staff nurses, nurse practitioners, nurse educators, nurse managers, dietitians, lactation consultants, clinical nurse specialists, and occupational therapists. The protocol represents a synthesis of research evidence and expert opinion pertaining to the introduction and management of oral milk feedings for high-risk infants in the neonatal intensive care unit. This evidence-based neonatal oral feeding protocol is presented to share knowledge and skill required to create positive feeding experiences while assisting high-risk infants to achieve full oral feedings. Goals of this project include promoting consistent neonatal nursing feeding practices and changing the ethos in relation to feeding interactions between caregiver and infant in the neonatal intensive care unit. This culture change will assist nurses to identify what is unique about their professional practice, which is of particular importance given the skill mix resulting from hospital understaffing and a growing nursing workforce shortage.

Non-nutritive sucking in sick preterm infants

BACKGROUND

Non-nutritive sucking (NNS) by the newborn infant is a fundamental behaviour and is one of the first coordinated muscular activities in the fetus.

AIMS

Our objective is to study the NNS pattern in prematurely born infants, who had various conditions commonly associated with immaturity.

METHOD

A specially designed computer-based method that analyses and quantifies components of the NNS pattern was used.

SUBJECTS

The pattern of 51 clinically stable prematurely born infants (gestational ages 26-35 weeks) making a total of 206 observations were analysed and findings were compared with those obtained from 58, healthy preterm infants.

RESULTS

The rhythmic NNS pattern of alternating sucking and pauses was elicited in all examined infants, the earliest at post-menstrual age (PMA) 26 weeks. The role of PMA, the dominant predictor for several sucking variables seen in the control group, became diminished for the infants with risk factors but changes were otherwise similar. The infants' sucking activity and sucking frequency increased and the variability of the pattern declined with increased PMA and weight. Follow-up of a subgroup of infants revealed fewer sucking bursts per minute, slower sucking frequency and a greater variability of the frequency and amplitudes in those infants who developed sequelae.

CONCLUSIONS

It would, thus, appear that the NNS pre-programmed rhythm generator, primarily modulated by maturation in healthy preterm infants, becomes affected by known risk associated events and in infants who later develop sequelae. Quantification of the NNS pattern in preterm infants may be a valuable future component of their evaluation.

Non-nutritive sucking in the healthy pre-term infant

In the infant, sucking behaviour is one of the first coordinated muscular activities. It is under the control of the brainstem. In utero sucking is observed from 13 weeks' gestation. The healthy full-term newborn infant has a very stable rhythm of alternating bursts of sucking with pauses in between. The non-nutritive sucking (NNS) patterns of 58 low-risk prematurely born infants (gestational ages between 26 and 35 weeks) were studied using a specially designed computer-based method that analyses and quantifies NNS. A total of 183 observations were analysed. The typical NNS pattern with bursts of sucking activity separated by quiescent periods was recorded in all infants studied and was already present before 30 weeks of gestation. A gradual change over time of their NNS was seen. With increased maturation the sucking activity, sucking frequency, amplitude and burst duration all increased, while the variability of the sucking frequency and the duration of the intervals between bursts declined. Post-menstrual age (PMA) was the dominant predictor of this result but gender, state of activity and weight also influenced it to some extent. Girls had more sucking activity and a higher sucking frequency than boys. State of activity affected the stability of the rhythm. The weight of the infant influenced both sucking activity and duration of separate bursts.