Ventilator-circuit configurations for noninvasive ventilation in infants with acute respiratory failure: a randomized crossover trial

Patient–ventilator synchrony may differ across ventilator and circuit configurations during noninvasive ventilation (NIV) in infants. We compared an intentional-leak single-limb turbine configuration (SLC-turbine), a dual-limb turbine configuration with an active expiratory valve (DLC-turbine), and a dual-limb compressed-gas pediatric ICU configuration (DLC-PICU) in infants receiving NIV for acute respiratory failure In this single-center randomized crossover physiological study, infants underwent three 30-minute NIV phases in randomized order with unchanged pressure support, PEEP, and FiO₂. Esophageal pressure was used to assess the asynchrony index (AI), individual asynchronies, and inspiratory effort. Primary and secondary endpoints were AI differences between DLC-PICU and SLC-turbine and between DLC-PICU and DLC-turbine, respectively Twenty infants entered stabilization, 13 were randomized, and 12 completed the protocol (age 10 [7–21] months; SpO₂/FiO₂ 185 [160–220]). AI differed across configurations: 8.6% [6.7–16.5] with SLC-turbine, 25.4% [16.3–35.0] with DLC-turbine, and 45.7% [30.5–63.8] with DLC-PICU (p=0.0023). AI was higher with DLC-PICU than with SLC-turbine (Hodges–Lehmann difference +32.0%, 95% CI +13.9 to +50.1; p=0.0015) and DLC-turbine (+18.4%, 95% CI +5.9 to +36.3; p=0.021). Auto-triggering showed the clearest configuration-dependent difference and was more frequent with DLC-PICU than with SLC-turbine (7.5 [0.6–11.4] vs 0 [0–2.5] events/min; difference +5.30 events/min; p=0.0039), without a significant difference between DLC-PICU and DLC-turbine. Ineffective efforts, double triggering, and premature cycling did not differ across configurations. All NIV configurations reduced inspiratory effort versus unassisted spontaneous breathing, with no significant differences among NIV configurations AI was lower with SLC-turbine and DLC-turbine than with DLC-PICU and lowest with SLC-turbine. Auto-triggering showed the clearest configuration-dependent difference. All configurations reduced inspiratory effort versus unassisted spontaneous breathing, without significant between-configuration differences. Because ventilator platform, circuit and expiratory architecture, and device-specific control functions differed, effects of individual components cannot be determined. These findings are specific to the ventilators and configurations evaluated. Further studies should determine whether these physiological differences translate into improved NIV tolerance or short- and long-term clinical outcomes ClinicalTrials.gov, NCT04017780.