If you work with premature infants than you are probably familiar with efforts to increase Non-nutritive suck (NNS). Current research has shown that an external stimulus can increase NNS in infants, which may transfer into nutritive feeding and other gains. In this blog post we will take a look at two methods for increasing NNS: reinforcement and entrainment.
First, what is non-nutritive suck (NNS)? NNS is basically sucking without nutrients. When the infant engages in the suck-swallow-breath pattern without intake of nutrients, they are engaging in NNS (i.e., sucking on a pacifier). Many preterm infants are fed via gavage feeding (nutrients delivered via tube feeding) and need to develop a coordinated suck pattern so that they can transition to breast/bottle feeding. A 2005 Cochrane Review showed that infants who received NNS intervention had a significant decrease in length of stay in the NICU and transitioned to bottle feed better than children who did not receive NNS intervention. No other benefits were found in this review (i.e., weight gain, energy intake, heart rate, etc..).
How can music therapy help infants achieve a better NNS? Standley et al. (2010) completed a randomized control trial study where they investigated the effect of the Pacifier Activated Lullaby (PAL) on variables including weight gain and days until transition to nipple. Infants were randomly selected for age (32, 34, or 36 weeks adjusted gestational age) and for group (control group, 1x PAL intervention group, or 3x PAL intervention group). Results indicated that 34-week babies had a significant shortened length of gavage feeding with PAL; however, PAL trials significantly increased length of gavage feeding for 32-week babies. There were no significant results due to PAL intervention in days until discharge. There are several other studies on the PAL showing significant increases in variables (Standley, 2000, 2003) or non-significant trends towards improvements (Cevasco, 2005); however, the results vary between studies, likely due to changes in design or intervention application.
Another intervention that has been shown to increase NNS via an external stimulus is the use of a tactile entrainment device, or motorized nipple, that entrains the Central Pattern Generators (CPG) involved in the suck pattern. Barlow et al 2008 and Poore et al 2008 used a pneumatic pulsing pacifier that entrains the infant’s CPGs to the temporal pattern of the suck pulse train. Results indicated that the infants significantly increased their coordination of the NNS patterning and intake of nutrients when transferred to oral feeds. Although these studies are completed by speech pathologists/neuroscientists, they are using tactile entrainment in order to improve the suck pattern via dedicated CPG networks. In other words, although this is not music therapy, this is a very cool use of externally cued rhythmic synchronization.
These might be excellent techniques to use if you work with this population; however, both require specialized equipment and advanced training. For other clinicians, these studies provide a nice view of two different methods of reaching a clinical outcome. One employs music as reinforcement for change in behavior and the other on rhythmic entrainment of CPGs.
Further research is needed on both of these interventions. Perhaps even research from different labs showing similar findings of significance.
References:
Barlow SM, Finan DS, Lee J, Chu S. (2008). Synthetic orocutaneous stimulation entrains preterm infants with feeding difficulties to suck. J Perinatol., 28(8), 541-8. PMID: 18548084
Cevasco, A., & Grant, R. (2005). Effect of the pacifier activated lullaby on weight gain of premature infants. Journal of Music Therapy, 42(2), 123- 139. PMID: 15913390
Pinelli, J., & Symington, A.J. (2005). Non-nutritive sucking for promoting physiologic stability and nutrition in preterm infants. Cochrane Database of Systematic Reviews, Issue 4. Art. No.: CD001071. DOI: 10.1002/14651858.CD001071.pub2.