A newborn with which of the following clinical manifestations should receive nasal CPAP?

a. Substernal retractions, PaCO2 = 65 mm Hg, PaO2 = 48 mm Hg, FIO2 = 0.4
b. Tachypnea, nasal flaring, PaCO2 = 50 mm Hg, PaO2 = 50 mm Hg, FIO2 = 0.6
c. Grunting, substernal retractions, pH = 7.20, PaCO2 = 70 mm Hg, PaO2 = 40 mm Hg, FIO2 = 0.7
d. Tachypnea, pale skin, pH = 7.32, PaCO2 = 45 mm Hg, PaO2 = 75 mm Hg, FIO2 = 0.21

ANS: B
A newborn with tachypnea, nasal flaring, a PaCO2 of 50 mm Hg, a PaO2 of 50 mm Hg, and an FIO2 of 0.6 meets the criteria for nasal CPAP. A newborn with these findings has adequate mi-nute ventilation, as evidenced by the PaCO2 of 50 mm Hg, but also has hypoxemia that is not be-ing corrected by an FIO2 of 0.6. The newborn in option A (substernal retractions, PaCO2 = 65 mm Hg, PaO2 = 48 mm Hg, FIO2 = 0.4) does not have an adequate minute ventilation and requires some ventilatory assistance. Mechanical ventilation is indicated for the newborn in option C (grunting, substernal retractions, pH = 7.20, PaCO2 = 70 mm Hg, PaO2 = 40 mm Hg, FIO2 = 0.7), because this patient has respiratory acidosis and uncorrected hypoxemia. The newborn in option D (tachypnea, pale skin, pH = 7.32, PaCO2 = 45 mm Hg, PaO2 = 75 mm Hg, FIO2 = 0.21) has two of the physical indications for CPAP, but the ABG findings demonstrate adequate oxygenation.