Next StepTM Resuscitator as a Novel Device for Providing Volume-Targeted Ventilation in the   Delivery Room
Creators: Tran, Kim
Publisher: name: University of Alberta Library
Year: 2024

<p>Approximately 13-26 million newborns worldwide require breathing assistance at birth. Positive pressure ventilation (PPV) is the cornerstone of neonatal resuscitation. The purpose of PPV is to help the newborn develop a functional residual capacity by delivering an adequate tidal volume (VT). Traditional neonatal resuscitation devices, i.e., the self-inflating bag (SIB) and T-Piece devices are pressure-limited. This mode of ventilation provides a constant inspiratory flow to deliver a set inspired VT. However, if a constant volume of air is being delivered, this can result in volutrauma as the infant’s lung mechanics will fluctuate post-delivery. Modern mechanical ventilators, such as the Dräger VN500, FabianTM HFO, and Leoni Plus use flow sensors to deliver volume-targeted ventilation, which is a mode of ventilation that delivers a stable VT by varying the PIP on a breath-by-breath basis. Recently, a new ventilator was developed called the Next StepTM Resuscitator. Compared to the other ventilators, the Next StepTM has not been extensively studied. In this thesis, the Next StepTM’s performance in providing PPV and its internal properties (i.e., power usage and the time it takes to deliver a target oxygen concentration) were examined in a series of animal and observational studies.  </p>

<p>First, using a neonatal piglet model, we compared the Next StepTM to different ventilation strategies: self-inflating bag (SIB) only, SIB+respiratory function monitor (RFM), T-Piece only, T-Piece+RFM, and FabianTM HFO, to examine which device/strategy can maintain the most consistent VT at ~0.5 cmH2O and ~1.5 cmH2O compliance levels. The Next StepTM and FabianTM HFO provided the most stable VT during PPV (5.10 and 4.76 mL/kg at ~0.5 cmH2O compliance; 5.22 and 4.43 mL/kg at ~1.5 cmH2O compliance, respectively) with no significant differences between the two devices, at all compliance levels tested. </p>

<p>Second, we examined the amount of time it takes for the Next StepTM to achieve changes in oxygen (O2) concentration compared to the Dräger VN500, Leoni Plus, and T-Piece resuscitators (GE, Neo-Tee and NeoPuff). Providing excessive oxygen (100% O2) to the preterm infant can cause oxidative stress whilst providing too little O2 can prevent them from reaching an optimal O2 saturation level, increasing their risks of death and intraventricular hemorrhage. The mean  SD time required to achieve FiO2 changes at 10 L/min was 321 s, 253 s and 362 s for the Leoni Plus, Next StepTM, and Dräger VN500, respectively, at a VT of 4 mL/kg. At a VT of 6 mL/kg, the mean  SD time required to achieve FiO2 changes at 10 L/min for the Leoni Plus, Next StepTM, and Dräger VN500 was 321 s, 283 s and 352 s, respectively. As for the GE T-Piece, Neo-Tee and NeoPuff, the mean  SD time required to achieve changes at 10 L/min was 152 s, 171 s and 191 s, respectively. Overall, there was a lag time of approximately 30 s for the ventilators at a VT of 4 mL/kg and 6 mL/kg. For the T-Pieces, there was a lag time of approximately 20 s. </p>

<pre><code>Third, we compared the amount of electrical power the Next StepTM uses compared to the Dräger VN500, FabianTM HFO, and the Leoni Plus when providing PPV and continuous positive airway pressure (CPAP). A barrier to the installation and use of mechanical ventilators in developing countries is access to electricity. In this study, we found that the Next StepTM used the least amount of power when providing PPV regardless of changes to the respiratory rate and positive end expiratory level (range): 18.47-21.04 W for the Next StepTM versus 89.6-96.1 W for the Dräger VN500, 64.56-65.04 W for the Leoni Plus, and 27.37-29.34 W for the FabianTM HFO. Similarly, the Next StepTM used the least amount of power when providing CPAP: range: 9.95-11 W for the Next StepTM versus 98.6-98.6 W for the Dräger VN500, 64.35-65.25 for the Leoni Plus and 22.7-23.45 W for the FabianTM HFO. 
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