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

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

A randomized controlled clinical trial evaluates cerebral blood flow changes associated with HFOV-VG in comparison to HFOV alone in preterm neonates with respiratory insufficiency during the period of invasive respiratory support

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

High Frequency Oscillatory Ventilation, Volume Guarantee-High Frequency Oscillatory Ventilation, Preterm, Cerebral Blood Flow

After documenting parental consent, preterm neonates with respiratory insufficiency randomly ventilated on (HFOV-VG ) will be assessed by doppler cerebral blood flow velocity measurements

After documenting parental consent, preterm neonates with respiratory insufficiency randomly ventilated on (HFOV) will be assessed by doppler cerebral blood flow velocity measurements

ventilator settings will be recorded such as: inspiratory: expiratory ratio (I:E), fractionated inspired oxygen (FiO2), mean airway pressure (MAP), frequency (HZ), delta P and high-frequency tidal volume (VThf).

ventilator settings will be recorded such as: inspiratory: expiratory ratio (I:E), fractionated inspired oxygen (FiO2), mean airway pressure (MAP), frequency (HZ), delta P

Investigate the effect of combining the VG mode with HFOV (HFOV-VG), versus the effect of HFOV alone, on Doppler cerebral blood flow velocity measurements

Evaluate the efficiency of HFOV-VG in comparison with HFOV alone as a rescue therapy in providing adequate neonatal ventilation and its possible impact on the short-term clinical outcome in terms of mortality and morbidities of these preterm neonates.

Chest x ray grading of RDS performed to patient before and after the assigned mode to compare lung aeration degree

Inclusion Criteria: Preterm neonates with gestational age ≤ 35 weeks. Neonates with various causes of respiratory failure: respiratory distress syndrome (RDS), air leak syndromes, pneumonia, or pulmonary hemorrhage, failing with conventional ventilation (i.e. when conventional ventilation failed to maintain either oxygenation or ventilation) and are switched to HFOV as a rescue therapy. Exclusion Criteria: Preterm neonates with major upper or lower airway anomalies. Preterm neonates with significant congenital anomalies including cardiac, abdominal or respiratory