Behavioral and Physiologic Effects of Nonnutritive Sucking during Gavage Feeding in Preterm Infants

Abstract

Behavioral and physiologic responsivity to nasogastric gavage feeding was assessed in 36 preterm infants on 2 consecutive d. On one of these days, a pacificr was provided during and after the gavage segment of the standardized protocol. The protocol was divided into segments that included baseline, preparatory handling, prcgavagc, gavage, and postgavage periods. Patterns of cardiac (heart period and vagal tone), oxygen saturation, behavioral state, and defensive behavioral responses to gavage were quantified. Thcsc stable pretcrm infants responded to handling and gavagc feeding with reductions in heart period, vagal tone, and oxygen saturation. Thcsc responses were not altered by provision of a pacifier, although there was a tendency for fewer episodes of bradycardia and oxygen desaturation. Conversely, behavioral state was affected Infants w h o remain hospitalized after the initial postpartum period are exposed to multiple iatrogenic stressors during neonatal intensive care and are vulnerable to the potentially destabilizing effects of these events (1). Such vulnerability is manifest in disruption of physiologic stability after medical and caregiving procedures. Effects on blood oxygenation have been the most frequently investigated responses in these infants. Decrements in blood gas levels in response to both noninvasive procedures, such a s weighing, diapering, neurobehavioral examinations, and preparatory handling and cleansing before lumbar puncture, as well a s to invasive procedures, including blood sampling, endotracheal suctioning, and lumbar puncture, have been documented (2-7). significantly by nonnutritive sucking: when provided with a pacifier, infants exhibited less behavioral distress, spent less time in fussy and active awake states during and after feeding, and returned to a sleep state significantly faster. There is converging evidence to suggest that nonnutritive sucking lessens behavioral distress to iatrogenic stressors but docs not alter physiologic responsiveness.

Synthetic orocutaneous stimulation entrains preterm infants with feeding difficulties to suck

“…Repeated exposure to patterned orocutaneous events, on the order of 12 to 24 min per day in the NICU presented simultaneous with NG tube feeds over the course of 7-10 days, provides the preterm infant with a neural entrainment experience that facilitates the development and strengthening of central pathways that regulate suck. Establishing the NNS provides the infant with additional benefits, including improved state control pre-feed [35][36][37][38][39] and post-feed, 40 growth, maturation, gastric motility, whereas decreasing stress 2,6,35,40,41 and enhancing oral feeds. 42 The present study has also demonstrated a significant positive relation between oral entrainment intervention and the transition to oral feed as taken from the infants' daily feed log.…”

Gastrointestinal Function and Growth in Premature Infants: Is Non-Nutritive Sucking Vital?

“…31 Widstrom et al 28 found decreased somatostatin and increased gastrin levels in gastric aspirates of preterm infants that were allowed to suck on a pacifier during gavage feedings. Other studies have found that gastrin 20,31 and somatostatin 30 levels were not significantly altered in treatment and control groups.…”

“…23 In addition, these infants returned to a sleep state much faster. 20 One mechanism that has been postulated for the potential beneficial effect of NNS, that of improved weight gain, has been attributed to the optimal behavior states achieved with NNS. 24 General movements of the limbs, head, and trunk occur without a distinctive pattern or sequencing of the various body parts.…”

“…The reduced energy expenditure may contribute to weight gain. 20,23 A second mechanism in support of improved weight gain and enhanced gastrointestinal function is thought to be related to the effect of NNS on enzymes and hormones. 24 NNS is postulated to stimulate tissues in and around the base of the tongue, resulting in secretion of an enzyme called pharyngeal lipase.…”

The development of potentially better practices to support the neurodevelopment of infants in the NICU

“…One postulated mechanism is a stimulation of digestive and anabolic hormones, although measurable hormonal differences have not been demonstrated. 169 Non-nutritive sucking with oral support 170 is associated with positive changes in behavior including enhanced physiologic stability, 171-173 a more alert and receptive behavioral state for feeds 174,175 and diminished signs of stress 176 and improved pain response. 177 Systematic reviews of experimental evidence for the practice of non-nutritive sucking have found a beneficial effect on length of stay and response to pain, but did not find consistent benefit involving behavioral states, sucking improvement, gastric emptying or weight gain.…”