Answer:
We must all be thoughtful as we evaluate devices that are designed or marketed to develop a skill. It is the thoughtful use of a modality, or the thoughtful decision not use it, based on the clinical assessment of our patient and the evidence, that should be our guide, both in the NICU or in any other level of care in which SLPs are a part of the team.

My NICU clinical experience for over 28 years suggests that PAL (Pacifier Assisted Lullaby)  is not an answer for the feeding/swallowing problems preterm infants present, and may actually inhibit functional skill (i.e., feeding). The issue for preterm infants is more complex than a “sucking problem.” Feeding problems in the NICU are rarely so simple, though sometimes a “poor suck” is unfortunately perceived as the reason for many of them. Learning to feed, both effectively and safely, is a complex, multifaceted challenge for preterm infants.¹

I have been part of the team in two large level III NICUs, and many of those babies have been extremely preterm. Many have respiratory distress syndrome (RDS) or CLD (Chronic Lung Disease), requiring intubation and ventilation, and/or need supplemental oxygen in the course of their recovery. We have not observed a direct detrimental effect on non-nutritive suck (NNS). These infants typically demonstrate effective non-nutritive sucking when ready to initiate bottle feeding, with respiratory issues being the paramount barriers. We have found that the NNS typically emerges with development and positive support during care. For all infants, our nurses provide excellent oral care, including developmentally appropriate hand-to-mouth, rooting and pacifier activities, to support development of non-nutritive sucking. For infants with delays in onset of oral feeding due to medical status or those profiled as likely to be high-risk fragile feeders, the speech-language pathologist is added to the team to provide positive early pre-feeding and graded swallowing experiences. This helps the infant make the transition to nutritive sucking more safely and effectively.²

The challenges preterms encounter in learning to feed are most often the direct sequelae of residual respiratory problems. These problems (e.g., tachypnea, increased work of breathing, compensatory breathing behaviors, breath-holding) jeopardize the coordination of sucking, swallowing and breathing. ¹  This can lead to respiratory fatigue and incoordination, or indeed adverse events such as choking, coughing and color change. Even infants with excellent NNS can have significant problems learning to suck nutritively because their drive to suck is often stronger than their physiologic sense of oxygenation.³

Very often the co-morbidities of early gestation, lower birth weight and attendant respiratory sequelae make feeding a challenge. The NNS, for which PAL was developed, has not been the issue delaying discharge.

It is also  important to recognize that the NNS and the nutritive suck are very different in their rate and rhythm due to the addition of fluid with nutritive sucking. This renders non-nutritive and nutritive sucking different developmental skills. Lingual patterns on ultrasound have shown significantly greater displacements and excursions when a preterm infant was sucking nutritively vs. non-nutritively on a pacifier.⁴

The NNS is not in itself a predictor of nutritive success (i.e., bottle feeding), research has found.⁵
NNS is just one of several domains that require consideration when contemplating the introduction of oral feeding. While found to be helpful, typical non-nutritive interventions have not been shown to decrease length of stay.⁶

A recent study reported that a non-nutritive stimulation program in an NICU did not result in earlier weaning from an nasogastric (NG) tube or earlier discharge when compared to similar infants without that intervention.⁷

In addition, PAL is designed to foster, and has as its outcomes, longer sucking bursts. Longer sucking bursts are problematic for the preterm. Longer sucking bursts may inadvertently, and likely do, increase WOB and overall respiratory effort. This “drain” on the infant’s respiratory reserves can have detrimental effects on the functional skill of feeding,⁸   as PAL is often provided just prior to a feeding.

Also, during PAL, it is likely at the preterm infant is not able to stop on his own at the appropriate junctures to take a series of deep breaths. This is directly related to immaturity, i.e. the drive to suck can inhibit the drive to breathe in the preterm, as he cannot register changes in CO2 versus O2, which can be a by-product of continuous sucking. So we often see a continuous sucking pattern with the pacifier and with PO feeding.⁹  While continuous sucking may sound like a hallmark of skill, in the preterm infant it can destabilize the autonomic system, lead to breath-holding or insufficient breaths, which can lead to desaturation, and potentially a cascade of events leading to decompensation. So sucking, faster sucking or engaging in longer sucking bursts, is not necessarily good for the preterm and typically is not. Sucking can’t be looked at in isolation, as it is part of a dynamic physiologic event that has multiple system implications/effects. ¹⁰   When the focus is on sucking itself, i.e. with PAL, we are not providing the preterm with the careful support required to integrate breathing with sucking. Then sucking activities provided can actually be detrimental to motor-learning, and potentially increase stress on a physiologic level.¹¹  This can then lay down neural pathways that, instead of facilitating positive learning, may move the infant away from learning to feed.¹²

While it may seem to some that enhancing sucking can be the answer for feeding issues that delay discharge, it is just not that simple. NICU infants learning to feed require dynamic, infant-guided supportive strategies during both pacifier sucking and during feeding, based on watchful vigilance and continuous feedback from the infant. The focus is on physiologic stability, active participation of the infant, and coordination of sucking with swallowing and breathing.⁵   This approach is more likely to promote readiness for  and eventual swallowing safety, support adequate nutrition, and result in the earlier discharges we have seen in the NICUs I have been fortunate to work in.

As you are undoubtedly aware of, supporting successful feeding for preterm infants goes way beyond sucking. For those infants who indeed do have “sucking” problems, then the involvement of the SLP, who can problem-solve with reflective/critical thinking, is far better than a referral for PAL, in my opinion.

References

1. 1. Shaker, C.S. (2013) Reading the Feeding. The ASHA Leader – American Speech-Language-Hearing Association.
2. 2. Shaker, C.S. (2013) Cue-Based Co-regulated Feeding in the NICU: Supporting Parents in Learning to Feed Their Preterm Infant. Newborn and Infant Nursing Reviews (2013) 13 (1): 51-5
3. Shaker, C.S. (2012) Feed Me Only When I’m Cueing: Moving Away From a Volume Driven Culture in the NICU. Neonatal Intensive Care, Journal of Perinatology-Neonatology, 25 (3) May-June, 27-32.
4. Miller, J.L., Kang, S.M. (2007).Preliminary ultrasound observation of lingual movement patterns during non-nutritive versus non-nutritive sucking in a premature infant. Dysphagia, 22: 150-60.
5. Lau, C., Kusnierczyk, I. (2001). Quantitative evaluation of infants’ non-nutritive and nutritive sucking. Dysphagia, 16: 58-67.
6. Fucile, S., Gisel, E.G., Lau, C. (2002). Oral stimulation accelerates the transition from tube to oral feeding in pre-term infants. Journal of Pediatrics, 141: 230-36.
7. Bragelian, R., Rokke, W., Markestad, T. (2007). Stimulation of sucking and swallowing to promote oral feeding in premature infants. Acta Paediatrica, 96: 1430-32.
8. Thoyre, S.M., Shaker, C.S., Pridham, K.F. (2005). The early feeding skills assessment for preterm infants. Neonatal Network, 24: 7-16.
9. Shaker, C.S. (2010) Improving Feeding Outcomes in the NICU: Moving from a Volume-Driven to an Infant-Driven Approach. American Speech, Language, Hearing Association. Swallowing Disorders Division 13 Perspectives – Oct
10. Shaker, C.S. (1999) Nipple feeding preterm infants: An individualized, developmentally supportive approach. Neonatal Network, 18(3), 15-22.
11. Smith G.C., Gutovich, J. et al (2011) Neonatal intensive care unit stress is associated with brain development in preterm infants .Annals of Neurology. 70(4), 541-549.
12. Browne, J. V., & Ross, E. S. (2011). Eating as a neurodevelopmental process for high-risk newborns. Clinics in Perinatology, 38(4), 731.

Catherine