Different Settings of Nonsynchronized Bilevel Nasal Continuous Positive Airway Pressure and Respiratory Function in Preterm Infants: A Pilot Study

Objective  With this study, we evaluated the short-term effects of different modes and settings of noninvasive respiratory support on gas exchange, breathing parameters, and thoracoabdominal synchrony in preterm infants in the acute phase of moderate respiratory distress syndrome. Study Design  A feasibility crossover trial was conducted in neonates < 32 weeks' gestation on nasal continuous positive airway pressure (n-CPAP) or bilevel n-CPAP. Infants were delivered the following settings in consecutive order for 10 minutes each: • n-CPAP (5 cm H 2O) • bilevel n-CPAP 1 (Pres low = 5 cm H 2O, Pres high = 7 cm H 2O, T-high = 1 second, rate = 30/min) • n-CPAP (5 cm H 2O) • bilevel n-CPAP 2 (Pres low = 5 cm H 2O, Pres high = 7 cm H 2O, T-high = 2 second, rate = 15/min) • n-CPAP (5 cm H 2O). During each phase, physiologic parameters were recorded; the thoracoabdominal synchrony expressed by the phase angle (Φ) and other respiratory patterns were monitored by noncalibrated respiratory inductance plethysmography. Results  Fourteen preterm infants were analyzed. The mean CPAP level was significantly lower in the n-CPAP period compared with bilevel n-CPAP 1 and 2 (p = 0.03). Higher values were achieved with bilevel n-CPAP 2 (6.2 ± 0.6 vs. 5.7 ± 0.5 cm H 2O, respectively; p < 0.05). No statistical difference in the Φ was detected, nor between the three settings. Conclusion  Our study did not show any superiority of bilevel n-CPAP over n-CPAP. However, nonsynchronized bilevel n-CPAP might be helpful when additional pressure is needed. Key Points There is currently a high degree of uncertainty about the superiority of one modality and setting of noninvasive respiratory over another. Our study confirmed that non-synchronized bilevel n-CPAP might be helpful when additional pressure is needed for recruitment. A T-high of 1 second could possibly be better tolerated in this population, but further research is needed.