Fig. 5.

Physiologic targets for arterial blood gases in premature lambs supported for 21 days by invasive mechanical ventilation (IMV; VIP Bird, CareFusion, San Diego, CA, USA) or two approaches to non-invasive high-frequency nasal ventilation (NIV): VDR4 (Percussionaire, Sand Point, ID, USA) or VN500 (Dräger Medical, Lübeck, Germany). Our model prospectively targets arterial oxygenation (PaO₂) range between 60 and 90 mmHg and ventilation (PaCO₂) range between 45 and 60 mmHg. At day-of-life 6, either mode of NIV respiratory support required ~10% lower F_iO₂ to maintain the targeted PaO₂ range compared to IMV respiratory support. Pressure setting for peak inspiratory pressure (PIP) at the ventilators was comparable among IMV and both NIV modes of respiratory support, but PIP at the ventilator is not the same as mean intra-tracheal pressure during NIV. (See Fig. 7; adapted with permission from Null et al. [25].)