Soru

A newborn male, delivered at 38 weeks of gestation following an uncomplicated pregnancy, develops profound perioral and truncal cyanosis at 4 hours of life. His peripheral oxygen saturation is 58% on room air and increases to only 62% after 15 minutes of 100% fraction of inspired oxygen ($FiO_2$) via headbox. His respiratory rate is 65/min with minimal work of breathing. Cardiac auscultation reveals a single, loud second heart sound ($S_2$) and a faint, non-radiating systolic murmur at the left mid-sternal border. Urgent echocardiography confirms the aorta arising anteriorly from the right ventricle and the pulmonary trunk arising posteriorly from the left ventricle. The ventricular septum is intact, and color Doppler demonstrates a highly restrictive patent foramen ovale ($PFO$) with minimal bidirectional flow. Arrange the following interventions in the most appropriate chronological sequence for the management of this patient, from immediate life-saving stabilization to definitive treatment.