Does the choice of bottle nipple affect the oral feeding performance of very‐low‐birthweight (VLBW) infants?

Background: There is a continuous debate regarding the best bottle nipple to be used to enhance the bottle-feeding performance of a preterm infant. Aim: To verify that feeding performance can be improved by using the bottle nipple with the physical characteristics that enhance infants' sucking skills. Methods: Ten “healthy” VLBW infants (941±273 g) were recruited. Feeding performance was monitored at two time periods, when taking 1-2 and 6-8 oral feedings/d. At each time and within 24 h, performance was monitored using three different bottle nipples offered in a randomized order. Rate of milk transfer (ml/min) was the primary outcome measure. The sucking skills monitored comprised stage of sucking, suction amplitude, and duration of the generated negative intraoral suction pressure. Results: At both times, infants demonstrated a similar rate of milk transfer among all three nipples. However, the stage of sucking, suction amplitude, and duration of the generated suction were significantly different between nipples at 1-2, but not 6-8 oral feedings/d.

Conclusion: We did not identify a particular bottle nipple that enhanced bottle feeding in healthy VLBW infants. Based on the notion that afferent sensory feedback may allow infants to adapt to changing conditions, we speculate that infants can modify their sucking skills in order to maintain a rate of milk transfer that is appropriate with the level of suck-swallow-breathe coordination achieved at a particular time. Therefore, it is proposed that caretakers should be more concerned over monitoring the coordination of suck-swallow-breathe than over the selection of bottle nipples.     

Coordination of suck-swallow and swallow respiration in preterm infants

Safe oral feeding of infants necessitates the coordination of suck-swallow-breathe. Healthy full-term infants demonstrate such skills at birth. But, preterm infants are known to have difficulty in the transition from tube to oral feeding. AIM: To examine the relationship between suck and swallow and between swallow and breathe. It is hypothesized that greater milk transfer results from an increase in bolus size and/or swallowing frequency, and an improved swallow-breathe interaction. METHODS: Twelve healthy preterm (<30 wk of gestation) and 8 full-term infants were recruited. Sucking (suction and expression), swallowing, and respiration were recorded simultaneously when the preterm infants began oral feeding (i.e. taking 1-2 oral feedings/d) and at 6-8 oral feedings/d. The full-term infants were similarly monitored during their first and 2nd to 4th weeks. Rate of milk transfer (ml/min) was used as an index of oral feeding performance. Sucking and swallowing frequencies (#/min), average bolus size (ml), and suction amplitude (mmHg) were measured. RESULTS: The rate of milk transfer in the preterm infants increased over time and was correlated with average bolus size and swallowing frequency. Average bolus size was not correlated with swallowing frequency. Bolus size was correlated with suction amplitude, whereas the frequency of swallowing was correlated with sucking frequency. Preterm infants swallowed preferentially at different phases of respiration than those of their full-term counterparts. CONCLUSION: As feeding performance improved, sucking and swallowing frequency, bolus size, and suction amplitude increased. It is speculated that feeding difficulties in preterm infants are more likely to result from inappropriate swallow-respiration interfacing than suck-swallow interaction.     

Maturation of oral feeding skills in preterm infants

AIM: Safe and successful oral feeding requires proper maturation of sucking, swallowing and respiration. We hypothesized that oral feeding difficulties result from different temporal development of the musculatures implicated in these functions. METHODS: Sixteen medically stable preterm infants (26 to 29 weeks gestation, GA) were recruited. Specific feeding skills were monitored as indirect markers for the maturational process of oral feeding musculatures: rate of milk intake (mL/min); percent milk leakage (lip seal); sucking stage, rate (#/s) and suction/expression ratio; suction amplitude (mmHg), rate and slope (mmHg/s); sucking/swallowing ratio; percent occurrence of swallows at specific phases of respiration. Coefficients of variation (COV) were used as indices of functional stability. Infants, born at 26/27- and 28/29-week GA, were at similar postmenstrual ages (PMA) when taking 1-2 and 6-8 oral feedings per day. RESULTS: Over time, feeding efficiency and several skills improved, some decreased and others remained unchanged. Differences in COVs between the two GA groups demonstrated that, despite similar oral feeding outcomes, maturation levels of certain skills differed. CONCLUSIONS: Components of sucking, swallowing, respiration and their coordinated activity matured at different times and rates. Differences in functional stability of particular outcomes confirm that maturation levels depend on infants' gestational rather than PMA.     

Développement de l'oralité chez le nouveau-né prématuré

Preterm infants cannot readily transition from tube to oral feeding. Such difficulty often delays their discharge from the hospital and mother-infant reunion. Therefore, understanding the development of the necessary skills preterm infants need to acquire for safe and successful oral feeding is essential. It is now recognized that a mature sucking pattern consisting of the rhythmic alternation of suction and expression is not sufficient for an infant to feed by mouth safely. Rather, an adequate coordination of sucking, swallowing, and respiration appear to be crucial if the infant is to feed with no episodes of desaturation, apnea, bradycardia, and/or aspiration. Studies have shown the benefits of some interventions in facilitating oral feeding in the preterm infant. However, it remains to be determined whether these effects can be generalized.     

Interventions to improve the oral feeding performance of preterm infants

Aim: Preterm infants have difficulty oral feeding. We hypothesized that a specific sucking and swallowing exercises vs. no intervention accelerate the attainment of independent oral feeding through a faster maturation of infants’ oral feeding skills (OFS). Methods: Very low birthweight infants were randomized to a control, sucking and swallowing groups. Sucking consisted of active sucking on a pacifier, and swallowing of placing a milk bolus (0.05–0.2 mL) on the tongue where the bolus rests prior to entering the pharynx. Primary outcome was days from start to independent oral feeding (SOF‐IOF). Secondary outcomes included overall transfer (OT, % volume taken/volume prescribed), proficiency (PRO, % volume taken at 5 min/volume prescribed), rate of transfer (RT, mL/min) over the entire feeding and infants’ OFS levels. OFS levels were defined by PRO and RT. Results: Days from SOF to IOF vs controls (21 ± 2) were similar for the sucking group (19 ± 2) and shorter for the swallowing group (15 ± 2; p = 0.019). Only the latter infants demonstrated more mature OFS levels than controls. Conclusion: The swallowing exercise is an efficacious intervention in facilitating the attainment of independent oral feeding, but not the sucking exercise. We speculate that the swallowing benefit resulted from an accelerated maturation of infants’ OFS levels.     

Comparison of sucking patterns at introduction of oral feeding and at term in Israeli and American preterm infants

BACKGROUND: It has been hypothesized that early initiation of oral feeding in premature infants may enhance the maturation of sucking patterns. AIM: To compare preterm infant sucking characteristics in urban level III neonatal care units in the USA and Israel. The two hospitals have different practices regarding the introduction of oral feeding. METHODS: Infants were assessed at 34-35 wk postconceptional age (PCA) and at term. Sucking parameters were assessed with the Kron's Nutritive Sucking Apparatus. RESULTS: 70 infants (38 Americans and 32 Israelis) participated in the study. Oral feedings were initiated earlier (32.6 +/- 4.3 vs 34.5 +/- 1.8 wk PCA, p < 0.01) and full oral feedings were reached earlier (35.4 +/- 2.8 vs 36.5 +/- 2.5 wk PCA, p < 0.05) in the USA infants. American preterm infants produced significantly more sucks (p < 0.001), had a higher suck rate (p < 0.001), more sucks per burst (p < 0.05), and a shorter interburst width (p < 0.01) at 34 wk PCA than Israeli infants. At term, American infants produced significant more sucks (p < 0.001), higher suck rate (p < 0.001), shorter intersuck width (p < 0.001), and a shorter interburst width (p < 0.05) than the Israeli infants of the same PCA. CONCLUSION: Different practices in the care of preterm infants, such as postconceptional age at introduction of oral feeding, may play a role in the development of feeding and feeding organization at term.     

An evidence-based guideline for introducing oral feeding to healthy preterm infants

The ability of a preterm infant to make the transition from gavage to oral nipple feeding depends on the infant's neurodevelopment in relation to behavioral organization, to a rhythmic suck-swallow-breathe pattern, and to cardiorespiratory regulation. Research-based knowledge about infant neurodevelopment in these three areas has led to the creation of a semidemand feeding method to aid in this transition. The method combines the use of nonnutritive sucking to promote awake behavior for feeding, use of behavioral assessment to identify readiness for feeding, and systematic observation of and response to infant behavior cues to regulate frequency, length, and volume of oral feedings. Semidemand feeding may be individualized for healthy preterm infants. This article discusses both the relevant knowledge about neurodevelopment and the semidemand feeding method itself.     

A randomized study of the efficacy of sensory-motor-oral stimulation and non-nutritive sucking in very low birthweight infant

To assess if sensory-motor-oral stimulation and non-nutritive sucking gavage feeding enhances the oral feeding performance of preterm infants born between 26 and 32 weeks of gestational age. STUDY DESIGN: Very low birthweight infants (n=98) were randomized into a experimental and control group. Preterm infants in the experimental group received sensory-motor-oral stimulation and non-nutritive sucking and infants in the control group received a sham stimulation program. Both were administered from when they reached enteral diet (100 kcal/kg/day) until the beginning of oral diet. Primary outcome was length of hospital stay. RESULTS: Independent oral feeding was attained significantly earlier in the experimental group than the control group, 38+/-16 days of life (mean+/-S.D.) versus 47+/-17 days of life, respectively (P<0.001) There was significant difference in length of hospital stay between the two groups (41.9+/-17 (mean+/-S.D.) versus 52.3+/-19 days (P<0.01)). CONCLUSION: Sensory-motor-oral stimulation, together with early non-nutritive sucking (as soon as the newborn reaches full diet and is clinically stable) in very low birthweight preterm infants, as long as they are clinically stable, in this study, earlier initiation of oral feeding and earlier hospital discharge.     

Decreased ventilation in preterm infants during oral feeding

As respiratory difficulty may accompany nipple feeding in preterm neonates, we studied the effect of oral feeding on ventilation in 23 preterm infants. The infants composed two groups based on their postconceptional age at the time of study: Group A comprised 12 infants 34 to 35.9 weeks of age, and group B, 11 infants 36 to 38 weeks. Ventilation was measured via a nasal mask pneumotachometer, and sucking pressure via a nipple that also permitted milk delivery; transcutaneous PO2 and PCO2 were continuously monitored. The feeding pattern comprised an initial period of continuous sucking of at least 30 seconds, followed by intermittent sucking bursts for the remainder of the feed. When compared with an initial semi-upright control period, minute ventilation (V1) during continuous sucking fell by 52 +/- 6% (P less than 0.001) and 40 +/- 2% (P less than 0.001) in groups A and B, respectively. This was the result of a decrease in respiratory frequency and tidal volume and was associated with a fall in TcPO2 of 13 +/- 4 mm Hg (P less than 0.01) in group A and 10 +/- 2 mm Hg (P less than 0.01) in group B. During intermittent sucking, V1 and TcPO2 recovered partially only in the more mature infants (group B). At the end of the feed, TcPCO2 have risen by 3 +/- 1 mm Hg (P less than 0.001) in group A and by 2 +/- 2 mm Hg (P less than 0.05) in group B. Thus oral feeding results in an impairment of ventilation during continuous sucking and the subsequent recovery during intermittent sucking is dependent on postconceptional age.     

The early feeding skills assessment for preterm infants

Preterm infants develop the skills necessary to begin oral feeding as their health stabilizes and as they reach a postconceptional age that supports coordination of breathing and swallowing with oral-motor functioning. The time from initiation of oral feeding to full oral feedings (with adequate intake for growth and maintenance of physiologic stability) can vary from days to months for the preterm infant. The approach to feeding the infant during this transition period must be developmentally supportive and tailored to meet the needs of the individual. To accomplish this, caregivers--notably nurses and parents--need to communicate about the specific skills that the infant has gained, about skills that are emerging, and about skills that the infant has not yet developed. The Early Feeding Skills (EFS) Assessment is a checklist for assessing infant readiness for and tolerance of feeding and for profiling the infant's developmental stage regarding specific feeding skills: the abilities to remain engaged in feeding, organize oral-motor functioning, coordinate swallowing with breathing, and maintain physiologic stability. This article introduces the EFS.     

Evaluation of beneficial effects of nonnutritive sucking in preterm infants

The effects of nonnutritive sucking (NNS) were studied in 40 preterm infants weighing less than or equal to 1800 g and of less than or equal to 35 weeks gestation by using a pacifier. The provision of NNS accelerated the maturation of sucking resulting in a faster transition from gavage to oral feedings. Treated infants (20) were ready for bottle feeds 1.54 days earlier, took their bottle feeds 1.5 min/30 ml faster and were transferred out of the nursery on an average .5 days earlier than the control infants. No adverse effects due to NNS were observed throughout the period of study. This resulted in an earlier union with their mother, less maternal deprivation and decreased work load on the nursery staff. Used judiciously this simple and safe modality of providing a pacifier for NNS during tube feeding may be useful in the management of preterm infants.     

The effect of non-nutritive sucking on plasma insulin, gastrin, and somatostatin levels in infants

The aim of the present investigation was to study the effect of non-nutritive sucking on plasma levels of insulin, gastrin, and somatostatin in infants. These hormones were measured with radioimmunoassay in plasma collected from fullterm and preterm infants sucking a pacifier. In fullterm infants, sucking caused a significant increase of insulin levels from 13 +/- 10 microU/ml to 40 +/- 36 microU/ml and 21 +/- 17 microU/ml after 45 sec and 5 min respectively, from when the infants started sucking. A similar pattern was seen in preterm infants. In contrast, gastrin and somatostatin levels were not significantly affected. We suggest that sucking causes an activation of the vagal nerve, which results in the release of insulin. We also suggest that in infants, oral feeding is superior to bolus feeding, since in the latter case no vagal activation and consequently no release of hormones with anabolic properties occurs.     

Nonnutritive sucking during tube feedings: effects on preterm neonates in an intensive care unit

Preterm neonates (mean 32 weeks' gestation, 1,300 gm birth weight) were provided a pacifier for nonnutritive sucking during tube feedings in the intensive care nursery. Their clinical course, subsequent bottle feeding behavior, and performance on the Brazelton Neonatal Behavior Assessment scale were compared with those of control group infants. The infants provided with pacifiers averaged 27 fewer tube feedings, started bottle feeding three days earlier, averaged a greater weight gain per day, and were discharged eight days earlier for an average hospital cost savings of approximately $3,500. Formula intake was similar for the two groups, although nurses appeared to provide more feeding stimulation for the control infants. On the Brazelton scale, the infants provided with pacifiers showed weak reflexes more frequently. Increased restfulness and diminished activity level in these infants may have contributed to the appearance of weak reflexes. The consistency between these findings and those of previous investigators suggests that the provision of a pacifier for nonnutritive sucking during tube feedings may be a cost-effective form of intervention.     

Effect of early feeding on maturation of the preterm infant''s small intestine

To determine the response of the preterm infant's intestine to entire feedings at different postnatal ages, we recorded results of manometry of the gastroduodenum and determined fasting plasma concentrations of gastrin, gastric inhibitory peptide, neurotensin, and peptide YY three times in each of two groups: 27 preterm infants were randomly assigned to receive hypocaloric enteral nutrition on postnatal days 3 to 5 (early feeding) or on days 10 to 14 (late feeding). Initial observations (study 1) were performed by the fifth postnatal day; study 2 was performed on days 10 to 14, and study 3 on days 24 to 28. Early-fed infants received hypocaloric feedings immediately after study 1; late-fed infants did not receive enteral feedings until the completion of study 2. Although motor activity and fasting gastrointestinal peptide concentrations did not differ between groups at study 1, at study 2 early-fed infants had significantly more mature motor patterns than did babies not being fed. Early-fed infants also had significantly higher plasma concentrations of gastrin and gastric inhibitory peptide than did late-fed infants; neurotensin and peptide YY values were similar in both groups. By the time of study 3, when late-fed infants had also received enteral feedings, gut development was not different in the two groups. However, early-fed infants were able to tolerate full oral nutrition sooner, had fewer days of feeding intolerance, and had shorter hospital stays. Thus the provision of early hypocaloric nutrition was associated with earlier nutrition of preterm infants' intestinal function and resulted in improved feeding tolerance. These findings support the use of early feedings in preterm infants.     

Oral stimulation accelerates the transition from tube to oral feeding in preterm infants

OBJECTIVE: To assess whether an oral stimulation program, before the introduction of oral feeding, enhances the oral feeding performance of preterm infants born between 26 and 29 weeks' gestational age. STUDY DESIGN: Preterm infants (n = 32) were randomized into an experimental and control group. Infants in the experimental group received an oral stimulation program consisting of stimulation of the oral structures for 15 minutes. Infants in the control group received a sham stimulation program. Both were administered once per day for 10 consecutive days, 48 hours after discontinuation of nasal continuous positive air pressure. RESULTS: Independent oral feeding was attained significantly earlier in the experimental group than the control group, 11 +/- 4 days (mean +/- SD) versus 18 +/- 7 days, respectively (P =.005). Overall intake and rate of milk transfer were significantly greater over time in the experimental group than the control group (P =.0002 and.046, respectively). There was no difference in length of hospital stay between the 2 groups. CONCLUSION: An early oral stimulation program accelerates the transition to full oral feedings in preterm infants. This was associated with greater overall intake and rate of milk transfer observed in the experimental group when compared with the control group.     

Oral feeding in premature infants: advantage of a self-paced milk flow

An earlier study demonstrated that oral feeding of premature infants (<30 wk gestation) was enhanced when milk was delivered through a self-paced flow system. The aims of this study were to identify the principle(s) by which this occurred and to develop a practical method to implement the self-paced system in neonatal nurseries. Feeding performance, measured by overall transfer, duration of oral feedings, efficiency, and percentage of successful feedings, was assessed at three time periods, when infants were taking 1-2, 3-5, and 6-8 oral feedings/day. At each time period, infants were fed, sequentially and in a random order, with a self-paced system, a standard bottle, and a test bottle, the shape of which allowed the elimination of the internal hydrostatic pressure. In a second study, infants were similarly fed with the self-paced system and a vacuum-free bottle which eliminated both hydrostatic pressure and vacuum within the bottle. The duration of oral feedings, efficiency, and percentage of successful feedings were improved with the self-paced system as compared to the standard and test bottles. The results were similar in the comparison between the self-paced system and the vacuum-free bottle. Elimination of the vacuum build-up naturally occurring in bottles enhances the feeding performance of infants born <30 wk gestation as they are transitioned from tube to oral feeding. The vacuum-free bottle is a tool which caretakers can readily use in neonatal nurseries.     

Oral and nonoral sensorimotor interventions facilitate suck-swallow-respiration functions and their coordination in preterm infants

Background

Preterm infants are at high risk of encountering oral feeding difficulties. Early sensorimotor interventions may improve oral feeding skills in preterm infants.

Aim

To further explore the effects of an oral (O), tactile/kinesthetic (T/K), and combined (O + T/K) sensorimotor intervention on preterm infants' nutritive sucking, swallowing and their coordination with respiration.

Study design

Seventy-five infants (29 [0.3, standard error of mean, SEM] weeks gestation, 49 males/26 females) were randomly assigned to an O group involving sensorimotor input to the oral structures; a T/K group involving sensorimotor input to the trunk and limbs; a combined (O + T/K) group; and a control group.

Outcome measures

Stage of sucking, suction and expression amplitudes (mm Hg), suck–swallow ratio, stability of suck–swallow interval, and swallow–respiration patterns.

Results

The O group had significantly more advanced sucking stages, and greater suction and expression amplitudes than controls [p ≤ 0.035, effect size (ES) > 0.6]. The suck–swallow ratio and stability of suck–swallow intervals did not significantly differ among groups (p ≥ 0.181, ES ≤ 0.3). The three interventions led to fewer swallows bracketed by prolonged respiratory pauses compared to controls (pause–swallow–pause, p ≤ 0.044, ES ≥ 0.7). The T/K and combined (O + T/K) groups had greater occurrence of swallows bracketed by expiration than the control and O groups (expiration–swallow–expiration, p ≤ 0.039, ES ≥ 0.3).

Conclusion

The O intervention enhanced specific components of nutritive sucking. All three interventions resulted in improved swallow–respiration coordination. Sensorimotor interventions have distributed beneficial effects that go beyond the specific target of input.     

The Effect of Non-Nutritive Sucking on Plasma Insulin, Gastrin, and Somatostatin Levels in Infants

ABSTRACT. The aim of the present investigation was to study the effect of non-nutritive sucking on plasma levels of insulin, gastrin, and somatostatin in infants. These hormones were measured with radioimmunoassay in plasma collected from fullterm and preterm infants sucking a pacifier. In fullterm infants, sucking caused a significant increase of insulin levels from 13 ± 10 μU/ml to 40 ± 36 μU/ml and 21 ± 17 μU/ml after 45 sec and 5 min respectively, from when the infants started sucking. A similar pattern was seen in preterm infants. In contrast, gastrin and somatostatin levels were not significantly affected. We suggest that sucking causes an activation of the vagal nerve, which results in the release of insulin. We also suggest that in infants, oral feeding is superior to bolus feeding, since in the latter case no vagal activation and consequently no release of hormones with anabolic properties occurs.     

Clinical effects of oral motor intervention combined with non-nutritive sucking on oral feeding in preterm infants with dysphagia

ObjectiveTo explore the effectiveness of oral motor intervention combined with non-nutritive sucking in treating premature infants with dysphagia.MethodsSixty preterm infants admitted to the neonatal intensive care unit of the present study's hospital were selected and randomly divided into the control and intervention groups. The control group was given non-nutritive sucking intervention alone, while the intervention group was given oral motor intervention combined with non-nutritive sucking. The oral motor ability, milk sucking amount and sucking rate, feeding efficiency and outcomes, and the occurrence of adverse reactions were measured and compared.ResultsCompared to first-day interventions, preterm infant oral feeding readiness assessment scale-Chinese version (PIOFRAS-CV) scores of the two groups significantly increased after 14 days of intervention, and this score was higher in the intervention group compared to the control group. Similarly, after 14 days of intervention, the intervention group's milk sucking rate and amount were significantly higher than the control group. Also, after the intervention, the intervention group's total oral feeding weeks were considerably lower, while the feeding efficiency and body weight were significantly higher than the control group. Moreover, the overall adverse reaction rate in the intervention group was lower than that in the control group.ConclusionsOral motor intervention combined with non-nutritive sucking can significantly improve the oral motor ability of premature newborns, promote the process of oral feeding, improve the outcome of oral feeding, and reduce the occurrence of adverse effects. The combined intervention seems to have a beneficial effect on oral feeding proficiency in preterm infants.     

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.