Integration of suck and swallow rhythms during feeding in preterm infants with and without bronchopulmonary dysplasia

Abstract

The aim of this study was to define quantitative measures for assessing the integration and maturation of suck and swallow rhythms in preterm infants as they relate to each other. Fourteen preterm infants (eight males, six females; gestational age range 26 to 32 weeks) with bronchopulmonary dysplasia (BPD) and an age-matched cohort of 20 infants (10 males, 10 females; gestational age range 26 to 33 weeks) without BPD were studied weekly from time of initiation of oral feeding using simultaneous recordings of nipple and pharyngeal pressure. The integration of suck and swallow rhythms was quantified by using the coefficient of variation (COV) of the suck-swallow dyad interval. Infants without BPD had a significant correlation between increasing postmenstrual age (PMA) and decreasing COV of the dyadic interval (increasing stabilization; r=0.45; p=0.008). In the non-BPD cohort 35 weeks or less PMA, the mean dyadic COV was 0.42 (SD 0.12) versus 0.34 (SD 0.09) in those more than 35 weeks PMA (p=0.039). In contrast, dyadic stability in infants with BPD was not correlated with PMA. Infants with BPD of more than 35 weeks PMA had less dyadic stability (0.45, SD 0.10) than did age-matched controls (p<0.001). Dyadic stability was also correlated with feeding efficiency in the non-BPD group (r=0.46;p=0.007) but not in the BPD cohort. Therefore, ontogeny of rhythmic suckle feeding can be described quantitatively in preterm infants, allowing comparison with at-risk populations. Infants with BPD do not follow predicted maturational patterns of suck-swallow rhythmic integration.

Attainment of early feeding milestones in preterm neonates

“…These findings are consistent with the findings of previous studies of preterm neonates, which have reported that suckling skills [6][7][8] and the coordination of suckling, swallowing and breathing [9][10][11][12][13][14][15] improve with ongoing maturity. These findings are also consistent with previous studies that have suggested that certain morbidities affecting body-systems involved in feeding, such as the respiratory and circulatory systems, may affect the efficiency of suckle-feeding in preterm neonates.…”

“…[15][16][17][18][19][20] The results from these studies suggest that certain comorbidities affecting the respiratory and circulatory systems may affect the ability to suckle-feed in preterm neonates. [15][16][17][18][19][20] However, there is minimal information regarding the effects of morbidity affecting other body-systems involved in feeding, such as the digestive and nervous systems. In addition, there are no large studies that have specifically investigated the relationship between the overall degree of neonatal morbidity and age at commencement of suckle-feeds and/or age at attainment of exclusive suckle-feeding.…”

“…These findings are also consistent with previous studies that have suggested that certain morbidities affecting body-systems involved in feeding, such as the respiratory and circulatory systems, may affect the efficiency of suckle-feeding in preterm neonates. [15][16][17][18][19][20] It is also possible that the iatrogenic effects of interventions required to treat morbidities and/or the interruption of normal development caused by invasive medical interventions and time spent in hospital may also have affected preterm neonates' suckle-feeding ability as well as their stamina for the work of feeding.…”

“…5 Depending on their GA at birth, preterm neonates may display various degrees of immaturity of their nervous, anatomical and physiological control systems, which have the potential to affect the strength, coordination and efficiency of the skills required for suckle-feeding. Several studies have documented that for preterm neonates, suckling skills [6][7][8] and the coordination of suckling, swallowing and breathing [9][10][11][12][13][14][15] improve with ongoing post-natal maturation. However, few studies have specifically investigated the relationship between GA at birth and either GA at commencement of suckle-feeds or GA at attainment of exclusive suckle-feeding.…”

Coordination of Sucking, Swallowing, and Breathing and Oxygen Saturation During Early Infant Breast-feeding and Bottle-feeding

“…Thus, infants are able to maintain a relatively constant milk flow and continue breathing by inserting swallows into particular regions of the extant sucking and breathing relationship. The results are consistent with and extend the findings of earlier studies (3,4,20).…”