Oral Entrainment on Suck Development of Preterm Infants Born 23 to 34 Weeks Gestational Age (GA)
Condition: Preterm Birth
MeSH terms: Premature Birth
Study type: Observational

Summary: 
      The development of sucking behaviors in preterm infants is thought to reflect neurobehavioral
      maturation and organization. From a clinical perspective, the ability to feed depends upon a
      coordinated sucking, swallowing and breathing pattern. In preterm infants less than 32 weeks
      gestation, this ability is not usually effective enough to sustain full oral feeds. In the
      interim, infants are fed by gavage tube until they are mature enough to take milk directly
      from the breast or bottle (Pinelli, Symington, 2005). Non-nutritive sucking has been used
      during gavage feeding and in the transition from gavage to breast/bottle feeding. The
      rationale for this intervention is that non-nutritive sucking facilitates the development of
      sucking behavior and improves digestion of enteral feeds.
    

Detailed description: 
      Study Design Primary Hypothesis The use of a patterned oral somatosensory entrainment
      stimulation program (NTrainer©) will safely accelerate the development of oromotor skills
      (suck) in preterm infants and is expected to significantly enhance the development of oral
      feeding skills. Non-nutritive suck development will be assessed on several dimensions of
      oromotor output including suck burst structure, minute-rates for suck cycle production, and a
      novel quantitative measure of suck pattern formation known as the non-nutritive suck
      spatiotemporal index (NNS STI) (Poore, Barlow, Wang, Estep, 2007, revision for Dev Med Child
      Neurology; Poore, Barlow, Wang, Gu, 2007, in prep for Dev Med Child Neurol). Measures of
      feeding skill include measurement of the transition time (days) to 100% oral feed, feed rate
      (ml/min), pulse oximetry, and documentation of reflux or spit up events. Secondary measures
      will include documentation of infant growth rate compared to no intervention. The growth rate
      will be assessed by examining the change in weight, head circumference and length during the
      28 days following initiation of oral feedings. Safety will be assessed by monitoring
      mortality, and the occurrence of feeding problems (numbers of days when feedings are
      withheld; ie NPO days), necrotizing enterocolitis, and aspiration events.

      Enrollment We will conduct a randomized control trial to evaluate the efficacy of the
      NTrainer on suck development and oral feed performance.

      We estimate we will need to study 100 preterm infants to test our primary hypothesis. (see
      sample size calculations in Statistical Analysis section). Enrollment will include 50
      treatment / 50 controls. Expected ethnic proportion for Kansas [US Federal Census]African
      American 5.9%, Asian American 1.8%, Hispanic American 5.6%,Native American 0.9%, White 86.3%,
      All others --

      Study Population Inclusion Criteria

        1. Documentation of informed consent. Informed consent will be obtained by the principal
           investigator(s) and/or designated research staff for each subject before being
           randomized into the study. We have a PACIRB approved Spanish version of the consent form
           available for interested participants.

        2. Gestational age between 23 weeks and 0/7 days and 34 weeks as per the best estimate by
           the neonatologist.

        3. If subject is transferred to another hospital, the ability to obtain follow-up data on
           outcomes.

        4. Ready for oral feedings. Neonates who meet eligibility criteria (A-E) will be assessed
           by the health care team (neonatology and occupational/developmental therapist) with the
           NTrainer beginning at 32 weeks post menstrual age (e.g., this will be 9 weeks of age for
           a neonate born at 23 weeks estimated gestational age). If they are considered ready for
           feedings they will be enrolled. Feeding readiness criteria include:

      A. Initiate when the health care team feels the baby is ready to try oral feeds.

      B. Hemodynamically stable. C. Stable O2 saturation levels during suck (infant will maintain
      SpO2 levels ≥ 90 during suck).

      D. Alert and active: neurologic exam appropriate for post-menstrual age E. No signs of sepsis
      or intolerance of gastric feedings

      Exclusion Criteria

        1. Gestational age < 23 weeks or > 34 weeks.

        2. Any major congenital anomalies (chromosomal abnormalities, nervous system anomalies,
           cyanotic congenital heart disease, gastroschisis, omphalocele, diaphragmatic hernia
           and/or other major gastrointestinal anomalies).

        3. Major neurological injury including intraventricular hemorrhage (IVH grades III or IV),
           or periventricular leukomalacia (PVL).

        4. Not ready for oral feedings as determined by the health care team.

      Outcome Measures

      Primary Outcome Measures (Primary Study Endpoints)

        1. The Non-Nutritive Suck SpatioTemporal Index (NNS STI) will be used to characterize the
           emergence and integrity of the suck central pattern generator (sCPG) through
           quantitative and statistical analyses of suck pattern stability. This procedure involves
           the calculation of nipple compression variability across multiple suck bursts. By
           calculating the cumulative sum of the standard deviations of an amplitude- and time-
           normalized set of NNS pressure trajectories, suck development can be represented by a
           single numerical value known as the NNS STI. The mathematics underlying STI are well
           suited to quantitatively track the emergence of ororhythmic stereotypy during NNS
           development in preterm infants (Poore, Barlow, Wang, Estep, Lee, 2007). The STI
           indicates the degree to which the set of motor trajectories converges on a single
           underlying template, or the stability of the neuromotor sequences exhibited by the
           preterm infant. This approach is conceptually unique from all previous studies on suck
           development which have attempted to characterize ororhythmic activity through parametric
           analyses such as mean sucks per burst, sucks per second per burst, suck width and
           intersuck width. The NNS STI will be calculated at 7, 14, 21 and 28 days after
           randomization to assess maturation of suck coordination.

           Details of the NNS STI calculation: Two minutes of the digitized ororhythmic pressure
           waveform with the greatest number of pressure peaks greater than 1 cm H2O, reflecting
           each infant's most active period of oromotor output, will be selected for NNS STI
           analysis. Because analyses of NNS spatiotemporal stability depend on comparing suck
           bursts with a fixed peak (suck cycle) number, the first five peaks from five successive
           bursts will be identified from the two-minute ororhythmic pressure waveform sample. For
           infants with degraded NNS pattern structure, the first five most burst-like mouthing
           movements are identified, based on period, amplitude, and duration.

           The selection of NNS bursts and calculation of the non-nutritive suck STI will be
           completed with a specialized LabVIEW© software program developed in Dr. Barlow's
           laboratory known as NNS STI. NNS STI is programmed to initially perform pressure peak
           detection for each burst to identify the time location for each peak. After the desired
           pressure peak locations are identified, the start- and end-points for the selected NNS
           burst are calculated by extending the analysis window 300 samples prior to the first
           peak and 300 samples following the fifth peak, in order to ensure accurate pressure peak
           waveform discrimination. Amplitude and time normalization of these five bursts is
           completed next. Time normalization is based on linear interpolation, which projects the
           five-peak-bursts ensemble to an analysis window based on a preset abscissa scale of
           10,000 data samples. Amplitude normalization is accomplished by deducting the mean and
           then dividing by the standard deviation for each trajectory. The NNS STI represents the
           cumulative sum of the standard deviations, indexed at 100 ms intervals, on the
           normalized NNS burst waveforms.

        2. Transition-to-Oral Feed (TOF): Time from initiation of oral feedings to full independent
           feedings (i.e., no gavage supplementation and taking at least 120-180 ml/kg/day.)

        3. Length-of-Stay (LOS) in the NICU.

        4. Occurrence of any of the following during the 28 day study period:

             -  necrotizing enterocolitis

             -  clinical suspicion of aspiration during feeding event (i.e., cough, spit-ups, O2
                desaturation).

             -  number of days feeding withheld for more than 12 hours (NPO)

             -  death

      Secondary Outcome Measures

      Growth velocity during the 28 days after initiation of oral feedings:

        1. Weight Gain (gms/kg/day) = [wt (gms) at 28 days - bw (gms)] / bw / 28 days

        2. Head Growth (cm/wk) = [hc (cm) at 28 days - hc (cm) at birth] / 3 wks

           • Occipitofrontal circumference = place measuring tape around the front of the head,
           above the brow and the occipital area. The measuring tape should be above the ears.

        3. Length Growth (cm/wk) = [len (cm) at 28 days - len (cm) at birth] / 3 wks
           Abbreviations:birth weight (bw); weight (wt); grams (gms); head circumference (hc);
           centimeters (cm),length (len) and weeks (wks).

      During the course of the study, adverse events will be monitored to ensure that the rate of
      reported events does not exceed the expected rate.

      Randomization and Treatment Assignment Randomization will take place using an electronic
      randomization schedule generated by Minitab v. 15 statistical software program. Neonates who
      are started on a trial of oral feedings will be randomly assigned to one of two groups -
      initiation of oral feedings with the NTrainer or to the Control group.
    

Observational model: Cohort
Time perspective: Prospective
Sampling method: Probability Sample
Study population: 
        Preterm Infants Born Between 23 And 34 Weeks Gestational Age