Development of Swallowing Function in Infants with Oral Feeding Difficulties

Abstract

Background. Discharge of preterm infants is often delayed because of their oral feeding difficulties. Independent oral feeding is the last obstacle to pass after managing acute and chronic morbidities. We conducted this study to determine the prevalence, characteristics, and risk factors of swallowing dysfunction and suggest proper interventions to reduce aspiration and chronic lung injury. Methods. Infants admitted to the neonatal intensive care unit (January 2016 to December 2018) who were performed modified barium swallow study due to oral feeding difficulties were enrolled. Modified barium swallow study was done≥postmenstrual age 37 weeks to limit radiation exposure. Clinical data were collected retrospectively. Swallowing dysfunction was defined as inadequate epiglottic closure, laryngeal penetration, or tracheal aspiration according to result of the modified barium swallow study. Results. Among a total of 54 infants enrolled, nine (16.7%) were term infants, 13 (24.1%) were late preterm infants (gestational age, 34-36 weeks), and 32 (59.3%) were early preterm infants (gestational age<34 weeks). Gestational age and birth weight were smaller in infants with swallowing dysfunction. Total duration of mechanical ventilation and duration of invasive ventilation were longer in infants with swallowing dysfunction. The risk of swallowing dysfunction increased by 11.2 times for infants with gestational age<29 weeks compared to infants with gestational age≥29 weeks. Swallowing dysfunction was improved in most infants after they became matured. They showed different time and rate of maturation with the help of rehabilitation through swallow therapy and dietary modification with thickened formula. Conclusion. Preterm infants with gestational age<29 weeks or with longer ventilation duration are at a higher risk of aspiration. Rehabilitation of swallow therapy and dietary modification with thickened formula can be helpful interventions to prevent aspiration and chronic lung injury and reassure parents until independent oral feeding is possible.

A thickened formula reduces feeding-associated oxygen desaturation and bradycardia in preterm infants

“…Independent oral feeding requires sophisticated control of numerous phases, including sucking, swallowing, breathing, maturation of respiratory function to endure short pauses of ventilation during swallowing, and coordination of the suck-swallow-breathe cycle [ 9 , 10 , 22 , 23 ]. Studies have shown that 50%–60% of preterm infants with feeding desaturation exhibit swallowing dysfunction in video-fluoroscopic swallowing tests at term-equivalent age [ 11 , 24 ]. Further, thickened liquids were slower to reach the hypopharynx and remained there for a shorter period of time, improving swallowing function and safety in neurologically impaired patients such as those with cerebral palsy, brain damage, and neurodegenerative diseases [ 25 - 27 ].…”

“…9,10,22,23) Studies have shown that 50-60% of preterm infants with feeding desaturation exhibit swallowing dysfunction in video-fluoroscopic swallowing tests at term-equivalent age. 11,24) Further, thickened liquids were slower to reach the hypopharynx and remained there for a shorter period of time, improving swallowing function and safety in neurologically impaired patients such as those with cerebral palsy, brain damage, and neurodegenerative diseases. [25][26][27] In addition, adapting the flow rate has been shown to have positive effects on sucking patterns and suck-swallowbreathe coordination.…”

“…Preterm infants with BPD are at a higher risk of developing feeding problems and issues with breathing control during feeding. 11,31) During oral feeding, respiratory frequency decreases, the airway is closed while swallowing, and the following inhalation has a shorter inspiratory time with compensatory larger tidal volume. 13,22,30) Infants with BPD may not be able to decrease their respiratory rate to interdigitate with suck-swallow rhythms without compromising oxygenation and ventilation.…”

“…Studies have shown that apnea, desaturation, bradycardia, or disruption of the suck-swallow rhythm during feeding were more frequent in infants with BPD than in those without BPD. 11,31) As we studied pre-and post-TF feeding changes, we did not compare the effects of TF feeding between infants with and without BPD.…”

“…[1][2][3]6,7) The mechanisms attributed to unstable cardiorespiratory vital signs during oral feeding include poor coordination of the suckswallow-breath cycle, immature sucking power, immature oral structures, gastroesophageal reflux, and associated lung or airway diseases. [8][9][10][11][12][13][14][15] Given the diversity of the underlying etiologies and clinical manifestations of feeding problems in neonates, the lack of standardized diagnostic definitions and therapeutic strategies is challenging.…”