Adaptive mechanical backup ventilation for preterm infants on respiratory assist modes - A pilot study

Background: Mechanical respiratory-assist modes, such as assist/control, low-rate intermittent mandatory ventilation, continuous positive airway pressure, or proportional assist ventilation (PAV), require a continuous respiratory effort. Because of the frequent occurrence of periodic breathing and/or apnea, mechanical backup ventilation must be initiated during episodes of reduced or absent respiratory drive to maintain gas exchange. The common approach to this problem is a regular conventional mechanical ventilation, which is initiated and withdrawn in an "on/off" function. Objective: To develop and evaluate a mechanical backup ventilation mode that is adaptive to the rapidly changing breathing pattern of preterm infants. Design: Prospective randomized clinical crossover trial. Setting: Neonatal intensive care unit at the University of Munich, Germany. Patients: Preterm infants undergoing PAV. Interventions: The infants were ventilated with PAV using a newly developed adaptive backup support, with and without pulse-oximetry-guided operation (SpO₂-sensitive backup). Each infant was ventilated with both modes of backup support on 2 consecutive days, with the sequence randomized. Measurements and results: The analysis on 11 preterm infants showed a statistically significant and clinically relevant reduction of the incidence (33%) and duration of oxygen desaturations (52%) when SpO₂-sensitive adaptive backup support was used. Conclusions: SpO2-sensitive adaptive backup proved safe and effective in reducing the incidence and duration of oxygen desaturation in this short-term trial. This technology is potentially applicable to other assisted modalities of ventilation, such as noninvasive nasal ventilation.