Oral and respiratory control for preterm feeding

Abstract

Purpose of review: Feeding competency is a frequent and serious challenge to the neonatal intensive care unit survivors and to the physician-provider-parent teams. The urgency of effective assessment and intervention techniques is obviated to promote safe swallow, as attainment of oral feeding for the preterm infant/newborn is one of the prerequisites for hospital discharge. If left unresolved, feeding problems may persist into early childhood and may require management by pediatric gastroenterologists and feeding therapists. This review highlights studies aimed at understanding the motor control and development of nonnutritive and nutritive suck, swallow, and coordination with respiration in preterm populations.

Recent findings: Functional linkages between suck-swallow and swallow-respiration manifest transitional forms during late gestation and can be delayed or modified by sensory experience and/or disease processes. Moreover, brainstem central pattern generator (CPG) networks and their neuromuscular targets attain functional status at different rates, which ultimately influences cross-system interactions among individual CPGs. Entrainment of trigeminal primary afferents to activate the suck CPG is one example of a clinical intervention to prime cross-system interactions among ororhythmic pattern generating networks in the preterm and term infants.

Summary: The genesis of within-system CPG control for rate and amplitude scaling matures differentially for suck, mastication, swallow, and respiration. Cross-system interactions among these CPGs represent targets of opportunity for new interventions that optimize experience-dependent mechanisms to promote robust ororhythmic patterning and safe swallows among preterm infants.

Figure 1

Schematic representation of the simultaneous pressure recordings of sucking (suction and expression components), onset of swallowing, and respiration (upward deflection: inhalation) over time. Dotted lines on each tracing delineate measures of time interval (s) gr1 Swallow–respiration interfacings were identified by the time at which onset of pharyngeal swallowing and a particular respiratory phase occurred. The example shown by the dotted line between swallow and respiration is that of a swallow occurring at the beginning of inhalation. Reproduced with permission from Amaizu et al. [4••].

Figure 2

Schematic representation of swallow–respiration interfacings, including swallow at start inspiration/end expiration; swallow at end of inspiration/start expiration; swallow during inhalation position, swallow during exhalation; swallow interrupting inspiration; and a swallow episode when respiration is halted (>2 s) gr2 The yellow highlights indicate interface locations corresponding to safe swallows. Reproduced with permission from Amaizu et al. [4••].