Adaptive Dynamic Inspiratory Nasal Apparatus: Comparison to Traditional Nasal Continuous Airway Pressure (NCPAP)

Abstract

Background: The use of high flow nasal cannula has increased dramatically in the neonatal intensive care setting. High flow nasal cannula (HFNC) simulates a continuous positive airway pressure despite unpredictable leak by way of using a higher flow to “overwhelm” the resistive capacity of the nares and create a NCPAP like effect. There is no absolute way to assure that the transmitted pressures do not exceed what might be considered a safe range for the neonate. The ADINA (Adaptive Dynamic Inspiratory Nasal Apparatus) introduces an additional safety mechanism designed to adaptively restrict the amount of pressure that can be delivered to the nasal interface. Although flows can be entrained up to 4 LPM, airway pressure is limited by an adaptive pop off valve set at 10cm H2O. Even if the pop off mechanisms were to fail to actuate, the device would continue to provide high flow nasal cannula delivery at levels that are already in wide clinical use. Methods: Patients were randomized to receive either “standard” nasal CPAP with Hudson prongs or high flow nasal cannula with the ADINA. Hudson prongs NCPAP pressure was started at 4–8cm H2O. High flow nasal cannula was started at 2–4L/min of flow. Oxygen requirement, level of pressure or flow support, radiologic changes, blood gas measurement, time to wean off protocol, and failure to wean/necessity for endotracheal intubation were monitored. 19 subjects were enrolled. Objectives: 1. Real-time device actuation—Can high flow nasal cannula be delivered with the additional safety of a pop off that actuates in real time? 2. Comfort of interface—Can this novel device provide a high flow nasal cannula effect simulating CPAP at the same comfort levels as those provided by conventional nasal cannula? Results: See Table below. There were two parents who refused to consent out of concern that their child would randomize to CPAP. Discussion: Although there was significant difference apparent in days on ADINA versus NCPAP (p < 0.01) (9.8±8.6 vs. 1.4±0.7), a significant bias towards the ADINA cannula was evident (both towards selection and continuation). No patient failed within a week of starting ADINA, although several patients failed to tolerate NCPAP. Patients randomized to ADINA trended towards lower birthweight and post-conceptual age at the time of the study. No complications of air leak, hypotension, or barotrauma were evident in either group. Conclusion: ADINA appears to be at equivalent to NCPAP in providing non-invasive ventilation.