A 6-hour-old female neonate born to a 32-year-old multiparous woman at 39 weeks gestation presents with progressive respiratory distress. Delivery was complicated by thick, dark-green meconium-stained amniotic fluid. The infant required intubation and mechanical ventilation in the delivery room due to gasping respirations and poor perfusion (Apgar 3/10 at 1 min). On current examination, the baby is on synchronized intermittent mandatory ventilation (SIMV) with FiO₂ 0.80, yet remains hypoxemic (SpO₂ 82%) and hypotensive (mean arterial pressure 35 mmHg). Chest X-ray shows bilateral infiltrates with hyperinflation and a right-sided tension pneumothorax. Echocardiography reveals right-to-left shunting across the foramen ovale and ductus arteriosus with elevated right ventricular pressures. What is the most likely complication of meconium aspiration syndrome in this infant, and what is the next step in management?