Clinical Research Directory

HFOV + volume guarantee (VG) as the intervention group HFOV was provided only with piston or membrane oscillators capable of delivering true oscillatory pressure with an active expiratory phase (i.e., Acutronic FABIAN-III, SLE 5000, Löwenstein Med LEONI+, or Sensormedics 3100A). Other machines offering high frequency ventilation were excluded. The lung recruitment maneuver was performed as previously described, and lung volume was assessed by chest radiography or lung ultrasound, targeting the right diaphragm at the level of 8th-9th rib (or 7th-8th rib in case of air leak). Crossover between HFOV and CMV This study allowed infants who failed to respond to their assigned ventilation mode to receive a trial of the alternate mode. Crossover criteria for HFOV-assigned neonates included failure for 3 hours to maintain SpO2 ≥ 50% despite FiO2 of 1.0, PaCO2 \> 60 mmHg for 3 hours, or signs of ventilator-induced cardiac output reduction. Non-responders to HFOV were switched to CMV.

CMV as the standard group CMV was delivered by time-cycled, pressure-limited ventilators. Only pressure regulated volume control (PRVC) will be provided by any type of neonatal ventilator. Crossover criteria for CMV-assigned neonates included failure for 3 hours to maintain SpO2 ≥ 50% despite FiO2 of 1.0, PaCO2 \> 60 mmHg for 3 hours, or requiring \> 30 cm H2O PIP to sustain ventilation. Non-responders to CMV were switched to HFOV. Ventilator settings were adjusted at the discretion of the attending clinician to maintain a SpO2 between 90%-94%, a PaO2 between 50 and 80 mm Hg and a PaCO2 between 35 and 60 mm Hg and a pH between 7.20 and 7.45. PO2 and PCO2 levels were monitored using arterial blood gas analysis and/or transcutaneous monitoring in both groups.