NIH

It is well recognized that preterm infants have difficulty transitioning from tube to oral feeding (bottle/breast), particularly those born < 30 weeks gestation (term defined as 37-40 weeks gestation). Such difficulty frequently leads to prolonged hospitalization, delayed mother-infant reunion and increased medical cost. Poor oral feeding may result from immature oral-motor skills, disorganized or delayed swallowing, and/or in-coordination of sucking, swallowing, and respiration. The latter is essential if these infants are to feed safely, i.e., with no aspiration, and successfully, i.e., capable of finishing all their feedings by mouth with adequate daily weight gain. There is no understanding of when and how such coordination develops. Clinical signs of in-coordination typically include oxygen desaturation, episodes of apnea and bradycardia during feeding, and/or coughing/choking. We have developed a nipple device that allows for the simultaneous monitoring of sucking, swallowing, and breathing. With this tool, we have gained an understanding of the development of sucking in infants and established a 5-stage scale that assesses the level of infant sucking skills.

From our studies, we have noted that non-nutritive sucking, e.g., on a pacifier, matures before nutritive sucking. Insofar as swallowing is minimal during non-nutritive as compared to nutritive sucking, we speculate that sucking skills mature before sucking, swallowing, and breathing are coordinated. The maturation of the swallowing process in preterm infants is not well understood. Oral feeding difficulties resulting from disorganized and delayed swallow usually are diagnosed by videofluoroscopy. Knowledge of pulmonary maturation in preterm infants has progressed significantly over the last decade as reflected by the increased survival of the preterm population.

However, the adaptability of the respiratory system to regular interruption of airflow resulting from swallowing events during oral feeding is unclear. Infants are primarily abdominal breathers as a result of the immaturity of the rib cage effectors that restrict the mobility of the upper chest. It is uncertain to what extent such limitation may impair the swallow-breathe process during oral feeding when swallowing frequency is increased. Preterm infants < 30 weeks gestation remain in the hospital ~11 to 12 weeks. During this time, concern focuses primarily on their medical status. It is only after they are medically stable that oral feeding issues are addressed, generally during the last 3 weeks of their hospitalization.

In 2 of our earlier studies, we have observed that early interventions such as early introduction of bottle feeding (H # 6748) and the use of a non-nutritive stimulation program prior to the introduction of oral feeding (H# 7469), both initiated ~ 31 weeks postmenstrual age, accelerated the transition of these infants from tube to oral feeding. It is speculated that these early experiences prepared the neural and muscular structures implicated in sucking, swallowing and respiration to the function of oral feeding. When bottle feeding, infants are held usually in a relatively supine position similar to that used when they are breastfeeding. However, infants with anatomical oral anomalies, e.g., Pierre Robin syndrome, or conditions such as meningocele have benefited from being fed in a prone position. In general, this approach has facilitated their respiration during oral feeding.

Given that preterm infants <30 weeks gestation, during their prolonged hospitalization, receive minimal stimulation appropriate for the development of their immature anatomical structures and physiological functions, we hypothesize that interventions can be developed to compensate for such void. In as much as oral feeding difficulty can arise from sucking, swallowing, and/or respiration, the present protocol will evaluate 5 interventions aimed at ameliorating sucking, swallowing, respiration, and the interaction of swallow-breathe during oral feeding. Insofar as many preterm infants demonstrate long-term feeding disorders (40%), this study will follow the above subjects post-dicharge at 3,6,12,18, and 24 months corrected age for any long-term feeding issues.

Our primary outcome will be the number of subjects requiring more than 1 visit to a feeding specialist/feeding disorder clinic for oral feeding issues.Secondary outcomes will be collected from our Oral Feeding Sensitivity Checklist that rates the behavioral responses to stimulation approaching facial contact and stimulation inside the mouth and from the Pre-Speech Assessment Scale (PSAS) that assesses the infant/child's functional feeding abilities at different ages, e.g., duration of a meal, amount taken, types of food eathen by mouth, sucking liquid from bottle/breast/cup, spoon feeding (Doddill et al 2004; Morris 1982). These 2 checklists are available upon request. Subjects will be tested at the same ages for the Bayley Mental and Motor Scale of Infant Development as proper growth and development are expected to affect oral feeding performance.

First Aim: To evaluate the effect of the following 5 interventions on oral feeding performance of preterm infants (< 30 weeks gestation) versus control infants who do not receive any interventions and are fed in the "supine" position (30 degree from horizontal) as is the current practice in nurseries:

1. Efficacy of a sucking exercise in enhancing sucking behavior
2. Efficacy of a swallowing exercise in reducing the occurrence of delayed/disorganized swallow
3. Efficacy of the prone position during feeding in improving the coordination of suck-swallow-breathe.
4. Efficacy of the upright position during feeding in improving the coordination of suck-swallow-breathe
5. Efficacy of a combined intervention including both sucking and swallowing exercises and the optimal feeding position (prone, upright, or control) in the overall feeding performance of the subjects.

Second Aim: to follow the subjects' long-term oral feeding problems, if any, following the above interventions early on in life.

Other

Experienced personnel will perform the various interventions. Oral feeding interventions will be administered by our co-investigator, Verna Eschenfelder, who is an occupational therapist. She will also teach caretakers about feeding the infants in the prone and upright position based on their group assignment. These evaluations will be conducted so as not to interfere with any other procedures. These studies are not intensive nor invasive to the subjects. If indication of overstimulation is observed during the interventions, they will be halted. Assessment of oral feeding issues post discharge using the Oral Feeding Sensitivity Checklist and the PSAS will be under the supervision of Dr. Carol Redel, Director of the Feeding Disorder Clinic at TCH. The Bayley Mental and Motor Development Scale will be administered by Marie Tucich, a psychologist at the Meyer Center, TCH.

The subjects may not benefit from this study. However, potential benefits of the proposed interventions may include earlier attainment of independent oral feeding, earlier hospital discharge, and decreased long-term oral feeding problems.