Nasal Noninvasive NAVA in the Very Low Birth Weight Infant
Nasal Noninvasive NAVA in the Very Low Birth Weight Infant
The purpose of this study is to determine if a new type of mechanical ventilation, or
 breathing machine (called neurally adjusted ventilatory assist or NAVA), will provide
 additional support to infants who were born prematurely. Investigators are looking to
 determine if in two hours infants who weighed less than 1500 grams or 3 pounds 5 ounces, will
 demonstrate a decrease in the amount of carbon dioxide (the gas that humans exhale) dissolved
 in their blood as compared to prior to starting the study. This will be accomplished by
 enrolling infants who are stable on their current type of mechanical breathing that provides
 a constant air flow into the infant. This type of mechanical support helps keep the lungs
 inflated but does not help remove carbon dioxide. This study will change the type of
 mechanical support to a type of support called neurally adjusted ventilatory assist or NAVA.
 This type of mechanical support detects when the infant is breathing in by having electrical
 sensors on a feeding tube that is placed into the stomach through the nose or mouth. These
 electrical sensors detect when the diaphragm or the muscle that helps humans breath is trying
 to take a breath in. When the NAVA ventilator senses the attempt to breath, it provides
 additional air flow to make the effort of breathing easier. The ventilator will be attached
 to a tube or cannula that is placed into the infant's nose. After two hours of being on the
 NAVA ventilator a repeat measure of carbon dioxide in the blood will be performed by taking a
 small amount of blood from the infant's heel.
Baseline Data Collection:

 Demographic data: Patient gestational age at delivery, maternal betamethasone therapy, APGAR
 scores, admission weight, receipt of surfactant administered, age at extubation, time since
 extubation, current post menstrual age, and current weight.

 Baseline vitals and ventilation mode: Heart rate, blood pressure, FiO2, oxygen saturations,
 transcutaneous partial pressure of carbon dioxide (TCO2) and current mode of ventilation will
 be recorded four times in a one minute period and the values average to minimize normal
 variation. Intervention time will be manipulated to begin no later than one hour after the
 previous feeding, as to minimize interruption of feedings to no greater than 30 minutes.

 Safety Safety: TCO2 monitor will be attached to the infant and the device will be calibrated
 according to protocol (reference TCO2 monitor manual). Carbon dioxide diffusion through the
 skin will be monitored continuously during the intervention (Bromley 08) to avoid periods of
 hypo or hypercarbia.

 Edi Catheter placement: Edi catheter size will be selected according to infant's weight and
 length. It will be inserted according to manufacturer's guidelines and adjustments will be
 made to optimize positioning (reference NAVA manual).

 NAVA settings:

 Infants will be maintained on previous level of PEEP or calculated PEEP, rounding up to whole
 numbers. Initial NAVA level will be determined by starting with an initial NAVA level of 0.5
 microvolts/cm of H20. The NAVA level will then be adjusted either by increasing or decreasing
 to generate a PIP that is a minimum of 8 cm of H2O greater than the current PEEP. Apnea alarm
 will be set at 5 seconds, which will initiate the NAVA back up setting if no electrical
 activity is detected by the Edi catheter. Back up NAVA settings will be set with a PIP of 12
 cm of H20 greater than current PEEP, respiratory rate of 60 breaths per minute (RR) and
 inspiratory time of 0.5 seconds. Fraction of inspired oxygen (FiO2) will be adjusted to keep
 infant's oxygen saturations within previously established clinical parameters.

 Study Intervention Procedure and Data Collection:

 At initiation of intervention, and at time 30, 60, 90, and 120 minutes, heart rate (HR),
 respiratory rate (RR), tidal volume (TV), minute ventilation, FiO2, oxygen saturations, peak
 Edi and PIP will be recorded four times in a one minute period and the values average to
 minimize normal variation. Current NAVA settings, TCO2, and blood pressure (BP) will also be
 recorded. At 60 minutes of intervention if the TCO2 level has not decreased by 5 torr from
 baseline or has risen, the current NAVA level will be increased by 50%. At 90 minutes if the
 TCO2 level has not decreased by 5 torr from baseline or has risen; the NAVA level will be
 increased by 50% from the current level. At the completion of the study (120 minutes or pCO2
 outside of established limits) the HR, RR, BP, TV, minute ventilation, FiO2, oxygen
 saturations, peak Edi and PIP will be recorded four times in a one minute period and the
 values average to minimize normal variation. A capillary blood gas will be obtained according
 to standard unit protocol with a warmed heel.
Inclusion Criteria:

 -  birth weight less than 1,500 grams

 -  Clinical history of respiratory distress syndrome treated with surfactant

 -  Chronological age greater than or equal to seven days

 -  48 hours post-extubation or greater

 -  Medically stable per primary medical team

 -  Receiving ventilatory support on one of the following systems via nasal pharyngeal
 tube or nasal prongs:continuous positive airway pressure (CPAP), intermittent
 mechanical ventilation (IMV), or neutrally adjusted ventilatory assistance (NAVA)

 -  Receiving ventilatory support via high flow nasal cannula if the flow is large enough
 to provide a positive end expiratory pressure (PEEP) of 6 as defined by PEEP of 6 =
 0.68 * weight (kg) + 0.92

 -  Capillary blood gas via heel stick within 24 hours that demonstrates a pH of less than
 or equal to 7.35 and/or a partial pressure of carbon dioxide (pCO2) greater than or
 equal to 45 mmHg

 Exclusion criteria:

 -  Severe congenital abnormalities

 -  Grade III or IV interventricular hemorrhage.