333 - Non-Invasive Neurally-Adjusted Ventilatory Assist Decreases pCO2 in Extubated Premature Infants

Preterm infants often require mechanical ventilatory support, but prolonged endotracheal intubation is associated with airway injury, bronchopulmonary dysplasia (BPD), and developmental impairment. Non-invasive methods to assist ventilation in this population are needed. Non-invasive neurally adjusted ventilatory assist (NIV-NAVA) provides synchronized ventilatory support via measurement of diaphragm electrical activity, but prospective studies are limited in preterm infants.

Objective: To measure the efficacy of ventilation support of synchronized noninvasive ventilation via neurally adjusted ventilatory assist (NIV NAVA) in post-extubated premature infants via comparison of pre-and-post-NAVA capillary pCO2 and pH.

Design/Methods:

Prospective cross-over trial of preterm infants treated with surfactant for respiratory distress syndrome. Infants < 1500 g birthweight, > 7d of age, and extubated > 48 hours on stable CPAP were included. Parents provided informed consent. Infants were placed on NAVA support at stable PEEP with NAVA (cm H30/mV) level increased by 50% q 30min x 3. Capillary blood gas before and after 120 min study period were compared. Heart rate (HR), respiratory rate (RR), SpO2, blood pressure (BP), FiO2, and ventilator settings were measured q 30min. Transcutaneous CO2 monitoring was used for safety. Wilcoxon signed-rank test was used to compare pH, pCO2, and vital signs before and after intervention. Repeated-measures ANVOA was used to assess changes in HR, RR, BP, SpO2, FiO2, and ventilator settings across 4 study time points. SAS 9.4 was used for analysis.

Results: 29 infants were studied, mean gestational age 25 weeks (± 2.02 sd), mean post-menstrual age at study 32 weeks (± 3.5 sd). Mean PEEP was 7.5 cmH20 (±3 sd), FiO2 0.32 (± 0.16). HR, RR, BP, SpO2 were not affected by NAVA intervention. Mean pCO₂ decreased after NAVA (-2.2 mmHg (±3sd), p = 0.02), pH increased (+0.02 (± 0.04 sd, p = 0.03). HR, RR, FiO2 and SpO2 did not vary during the study period (table 2). Ventilator settings are shown in table 1.

Conclusion(s):

Non-invasive NAVA is effective in decreasing pCO2 and increasing pH in preterm infants on CPAP with a history of mechanical ventilation, without affecting vital signs.