Tube-fed preterm infants with respiratory distress syndrome who were treated with a therapeutic device rapidly learned to suck far better and transitioned to oral feeding faster than a control group of babies with the syndrome, a new study has found.¹

The NTrainer device, patented by the University of Kansas, in Lawrence, powers a Soothie silicone pacifier with a computer-controlled air pump to transform the nipple into a dynamically patterned pulsing touch stimulus on the surface of the infant's lips and tongue. Modeled extensively on the burst-pause suck dynamics of healthy preterm infants, the NTrainer device essentially teaches babies the correct pattern to produce the non-nutritive suck, what they normally do in the womb beginning as early as the second trimester of development.

Researchers conducted the initial clinical trial of the NTrainer at the neonatal intensive care units of Stormont-Vail Regional Health Care, in Topeka, KS, and the University of Kansas Medical Center in Kansas City. They compared 20 tube-fed preterm infants who had moderate to severe respiratory distress syndrome and were treated with the NTrainer to a control group of age-matched infants who had respiratory distress syndrome and received a sham consisting of a non-instrumented pacifier during tube feedings.

Respiratory distress syndrome, also known as hyaline membrane disease, is a common condition of prematurity, particularly in the youngest infants, because the lungs are too immature to survive outside the womb without the help of a ventilator and/or oxygen. It is the seventh leading cause of death among all infants younger than a year, fifth for African-American infants, and third for Hispanic infants.

Infants in the study who received the patterned NTrainer treatment exhibited a near doubling of non-nutritive suck burst complexity, a 50 percent to 100 percent increase on select suck burst production measures, and a tripling of their average daily oral feed levels to 72.8 percent compared to the untreated controls (23 percent).

All of the infants quickly learned to bottle feed, one of the main objectives of Stormont-Vail project partners José Gierbolini, MD, medical director of newborn services, and Joy Carlson, NP, neonatal nurse practitioner.

"We were delightfully surprised at the results," said study leader Steven Barlow, PhD, director of the Communication Neuroscience Laboratories and Speech Aerodynamics and Voice Laboratory of the Schiefelbusch Speech-Language-Hearing Clinic at the University of Kansas. "This demonstrates the potent effect of the patterned NTrainer orocutaneous stimulation to drive and reorganize the rapidly developing nervous system."

He and Donald Finan, PhD, an assistant professor in the Department of Speech, Language and Hearing Sciences at the University of Colorado, in Boulder, invented the NTrainer technology, which is named after the neuroscientific term "entrainment." They also invented its companion technology, the Actifier, a mobile crib-side workstation that can be configured to permit real-time assessment of oromotor ability and therapeutic intervention in the premature infant.

"Non-nutritive suck has been suggested by some neonatologists to provide a window into the development of the central nervous system," said Dr. Barlow. "The NTrainer system represents the first objective, physiologically-

based tools that give the physician and nurse almost instant feedback about the status of the infant's oromotor system through the assessment of [non-nutritive suck]."

For babies born too soon, the development of non-nutritive suck, which is the precursor behavior to nursing, often is disrupted abruptly by the life-saving but invasive breathing tubes that are inserted down the throat and feeding and oxygen tubes taped to a baby's nose and face to keep it from thrusting the tubes out.

Respiratory distress syndrome delays the release of infants from the neonatal intensive care unit, and those who cannot feed orally competently may be required to continue tube feedings at home, typically by way of a gastric tube. In worst-case scenarios children don't learn to take nourishment orally for months or even years, according to Dr. Barlow.

As an ongoing objective of the study, his research team will examine the effects of NTrainer therapy on the transition of infants to feeding safely orally and the length of hospital stay.

"In today's health care environment being able to send a baby home just one week earlier could save $28,000 to $30,000," Dr. Barlow said.

The National Institutes of Health awarded $2.6 million in funding to Dr. Barlow for a new clinical trial that began in the fall and will continue over the next five years at Stormont-Vail Regional Medical Center and Overland Park Regional Medical Center. The comprehensive study will examine the effects of early NTrainer intervention on the development of feeding skills, fine motor skills, brain development, and the acquisition of speech and language among 240 premature infants followed longitudinally until age 3.

Dr. Barlow hypothesizes that if the NTrainer can stimulate a specialized brain network known as the suck central pattern generator in infant brains through normal sucking patterns at the right time, approximately 32 weeks gestational age, development can proceed more normally for babies with respiratory distress syndrome.

Application of the NTrainer may benefit other preterm populations as well, including infants with bronchopulmonary dysplasia or Down syndrome and preemies with very low birth weight who are at risk for neurologic insults and compromised neurodevelopmental outcome.

The NTrainer system, which received clearance from the U.S. Food and Drug Administration (FDA) earlier this year, is being developed for market by KC BioMediX Inc. of Shawnee, KS. The first units will be available for the neonatal intensive care market in January.

Reference

1.???Barlow, S.M., Finan, D.S., Lee, J. (2008). Synthetic orocutaneous stimulation entrains preterm infants with feeding difficulties to suck. Journal of Perinatology, 28: 541-48.

Karen Henry is on staff at the University of Kansas.

Neonatal RDS

Neonatal respiratory distress syndrome (RDS) is most commonly a complication seen in premature infants whose lungs have not yet fully developed, according to MedlinePlus (www.nlm.nih.gov). The disease primarily is caused by a lack of surfactant, the slippery, protective substance that helps lungs inflate with air and keeps the air sacs from collapsing. Most cases are seen in babies born before 28 weeks. In addition toprematurity, risk factors for neonatal RDS include a brother or sister who had the condition, diabetes in the mother, cesarean delivery, delivery complications that lead to acidosis in the newborn at birth, multiple pregnancy and rapid labor. RDS often worsens for two to four days after birth, with slow improvement thereafter.