Swallow–Breath Interaction and Phase of Respiration with Swallow during Nonnutritive Suck among Low-risk Preterm Infants

Abstract

This study describes swallow-breath interaction and phase of respiration with swallow during nonnutritive suck (NNS) in low-risk preterm infants. Suckle and swallow, thoracic motion, and airflow were measured in 16 infants during NNS. Logistic regression models were used to describe swallow-breath interaction and phase of respiration with swallow. One hundred seventy-six swallows occurred in 35 NNS periods. Swallow-breath interaction occurred as: central apnea (CA), obstructive apnea (OA), or attenuated respiration (AR). AR was associated with increased weeks post-first nipple feeding. OA occurred less often in males and with increased weeks post-first nipple feeding. In looking at the phase of respiration, more swallows occurred at beginning expiration with increased gestational age, increased weeks post-first nipple feed, and increased weeks before first nipple feed. More swallows occurred at midexpiration with more swallows per study, increased birth weight (BWT), and weeks before first nipple feed. Fewer swallows occurred at end expiration with increased weeks before first nipple feed. Fewer swallows occurred at midinspiration with increased swallows per study. Fewer swallows occurred at apnea with increasing BWT, more occurred with increased swallows per study. In low-risk preterm infants, swallow-breath interaction progresses from CA and OA to AR. The phase of respiration with swallow shows a maturation progression.

Exploring Factors Related to Oral Feeding Progression in Premature Infants

“…16 Additionally, birthweight is related to improved coordination of breathe, suck, swallow leading to more efficient feeding. 17 Matsubara et al (2005) compared sucking bursts for eight VLBW with seven full-term infants and reported that VLBW infants exhibited lower sucking pressures and shorter sucking bursts, reducing feeding efficiency. 10 Our findings of the negative association between lower birthweight and longer oral feeding progression supports previous findings.…”

“…16 Larger birthweight was significantly associated with more coordinated breath, suck, and swallow cycles. 17 Infants with higher birthweights swallow at either mid-expiration or during apnea which was shown to significantly reduce the risk of aspiration. 17 However, premature infants with very low birthweight (VLBW) exhibit a significantly shorter sucking cycle length (amount of time from the peak of one suck to the peak of the next suck) and low sucking pressures (measured in mmHg as the strength of the suck – e.g.…”

“…17 Infants with higher birthweights swallow at either mid-expiration or during apnea which was shown to significantly reduce the risk of aspiration. 17 However, premature infants with very low birthweight (VLBW) exhibit a significantly shorter sucking cycle length (amount of time from the peak of one suck to the peak of the next suck) and low sucking pressures (measured in mmHg as the strength of the suck – e.g. the depth from the lowest pressure to the peak pressure of one suck), thus confirming that infants with lower weights have more difficulty with oral feeding.…”

Development of Swallowing Function in Infants with Oral Feeding Difficulties

“…Oral feeding in preterm infants with BPD is challenging because preterm infants already have respiratory problems such as decreased minute ventilation. Minute ventilation is even decreased during oral feeding [16,17]. Apnea or desaturation events during feeding is more frequent in infants with BPD compared to that in those without BPD.…”

Breathing and Swallowing: The Next Frontier

“…Reynolds et al studied swallowing-breathing interactions in 16 preterm newborns over a period of several weeks. 18 They found that, initially, the majority of nonnutritive swallows (NNS) occurred primarily during inhalation-exhalation transition points where the authors postulated that airflow was thought to be minimal. However, as gestational age increased, NNS swallows were more frequently timed with early exhalation.…”