Supplementary Material for: A new tool to assess patient-ventilator synchrony in preterm infants receiving non-invasive ventilation: a randomized crossover pilot study

Introduction: Nasal synchronized intermittent positive pressure ventilation (nSIPPV) is an effective non-invasive ventilation technique, especially for preterm infants.
Patient-ventilator synchrony is essential for providing effective respiratory support; however, no automated system is currently available for monitoring this parameter. A new tool for automatic assessment of patient-ventilator synchrony, the SyncNIV system, was developed and applied in this pilot study to evaluate differences between nSIPPV and non-synchronized nasal intermittent positive pressure ventilation (nIPPV) in preterm infants with respiratory distress.
Methods: This study involved designing a custom algorithm for signal analysis. Data were collected through a polygraph that could simultaneously gather respiratory data from the patients and ventilator. Patient-ventilator synchrony was evaluated by applying the SyncNIV system in a randomized crossover study designed to compare nSIPPV and nIPPV. The primary outcome was the mean instant Synchrony Index (i-SI), defined as the portion of the inspiration effort sustained by ventilator inflation, expressed as a percentage.
Results: Fourteen infants with a median (IQR) gestational age of 28.6 (25.6-30.3), were enrolled.
We analyzed 43,304 ventilator inflations and 50,221 patient breaths. The i-SI was 54.69% (44.49-60.09) in nSIPPV and 39.54% (33.40-48.75) in nIPPV, p<0.05.
Conclusion: The SyncNIV system confirmed better i-SI during nSIPPV than during nIPPV, demonstrating its effectiveness in assessing the differences between these two modes of non-invasive ventilation in preterm infants. The SyncNIV system could be a useful tool for optimizing the ventilation parameters and improving the effectiveness and comfort of respiratory support systems.