A 6-hour-old female neonate born at 39 weeks gestation to a 32-year-old mother with thick meconium-stained amniotic fluid (MSAF) is now in the neonatal intensive care unit. The infant was non-vigorous at birth (Apgar 4/6) with poor respiratory effort. Intubation and tracheal suctioning were performed immediately. She now requires mechanical ventilation with FiO₂ 0.8 to maintain SpO₂ 88–92%. Chest X-ray shows extensive bilateral infiltrates with severe hyperinflation and a right-sided pneumothorax. Blood gas analysis: pH 7.18, PaCO₂ 58 mmHg, PaO₂ 65 mmHg. What is the most appropriate next step in management?