Soru

A $41$-week-gestation male neonate is delivered via emergent cesarean section due to fetal bradycardia. The amniotic fluid is thick with meconium. In the delivery room, the infant is limp, cyanotic, and apneic. After initial stabilization with positive pressure ventilation, he begins spontaneous respirations but exhibits severe retractions and grunting. He is admitted to the neonatal intensive care unit. Despite receiving non-invasive continuous positive airway pressure with a fraction of inspired oxygen ($FiO_2$) of $1.0$, his pre-ductal oxygen saturation is $94\%$ and post-ductal oxygen saturation is $76\%$. A chest radiograph demonstrates bilateral coarse infiltrates with areas of lung hyperinflation. Arrange the following management and diagnostic interventions in the most appropriate escalating chronological sequence for this patient, from initial step to final salvage therapy.