Effect of Volume Guarantee-High Frequency Oscillatory Ventilation on Cerebral Blood Flow in Neonates

Neonatal respiratory distress (NRD) is one of the most common problems in the first few days of neonatal life. NRD has been reported to be prevalent in 5 - 29% of the NICU hospitalized neonates. High-frequency oscillatory ventilation (HFOV) has been used for more than three decades, it is a rescue maneuver for failed conventional mechanical ventilation. It delivers small tidal volumes to improve gas exchange. As it uses a low tidal volume, under the anatomical dead space at supra-physiological respiratory frequencies HFOV can reduce the risk of lung injury related to the ventilator and consequently reduce the risk of bronchopulmonary dysplasia HFOV is indicated for patients with neonatal air leak syndrome, persistent pulmonary hypertension, and meconium aspiration Several factors are known to influence cerebral perfusion during HFOV. Hypercapnia increases cerebral blood flow (CBF) while a reduction in PaCO2 leads to cerebral vasoconstriction and decreases CBF, Hypoxia is also known to increase CBF via cerebral vasodilation HFOV with volume guarantee (HFOV-VG) is a promising new ventilator mode for the treatment of respiratory failure in newborns. HFOV-VG is expected to result in less lung injury since it reduces fluctuations of high frequency tidal volume (VThf), reduces the number of out-of-target pCO2 values and provides fewer hypoxia attacks compared with HFOV alone