A 34-week-gestational-age newborn has ABG results at birth: pH 7.33, PaCO2 46 mmHg, PaO2 44 mmHg, HCO3- 23 mEq/L. What should the neonatal-pediatric specialist recommend?

• A. Mechanical ventilation
• B. Intubate and initiate CPAP at 4 cmH2O with an FiO2 of 0.60
• C. Place the newborn in an oxygen hood and administer an FiO2 of 0.45
• D. Administer oxygen via an isolette at an FiO2 of 0.55

Answer: (C)

When a preterm newborn shows hypoxemia with only a mild respiratory acidosis at birth, the safest initial step is to support oxygenation with a simple, noninvasive method and use the lowest FiO2 that achieves adequate oxygenation. Placing the baby in an oxygen hood and delivering an FiO2 of about 0.45 provides enough supplemental oxygen to raise the PaO2 toward normal while avoiding the higher oxygen levels that come with more invasive methods. This approach also avoids unnecessary airway instrumentation and allows you to reassess quickly; if oxygen alone does not improve oxygenation or CO2 clearance, you can escalate to noninvasive ventilation (for example, CPAP) or, if needed, to intubation and ventilation. Higher FiO2 or invasive strategies at this stage carry greater risks, especially in a 34-week infant, and should be reserved for persistent hypoxemia, worsening acidosis, or respiratory fatigue.