Index of Suspicion in the Nursery

A healthy term neonate is born at a community hospital to a 26-year-old primigravida after an uncomplicated vaginal delivery. The prenatal laboratory parameters are normal amd negative for syphilis, human immunodeficiency virus, hepatitis B, and group B streptococci. The birthweight is 3.5 kg and the Apgar scores are 8 and 9 at 1 minute and 5 minutes, respectively. The neonate receives a vitamin K injection at the delivery suite. After an uneventful 1 hour postdelivery, the nurse notes that the infant appears “dusky” and “blue.” His temperature is 99.1°F (37.3°C), heart rate is 130 beats/min, mean blood pressure is 45 mm Hg, respiratory rate is 36 breaths/min, and oxygen saturation is 98%. Approximately 15 minutes later, he exhibits a gasping respiratory pattern, his oxygen saturation falls to 80%, and his respiratory rate is 64 breaths/min. Endotracheal intubation for respiratory distress is accomplished successfully. The mean blood pressure begins to fall, reaching a nadir of 30 mm Hg, at which time the heart rate increases to 160 to 180 beats/min. A capillary blood gas in room air reveals a pH of 7.40, Pco2 of 50 mm Hg, oxygen saturation of 82%, and bicarbonate value of 23 mEq/L (23 mmol/L), and a bedside blood glucose reads 52 mg/dL (2.9 mmol/L). The low blood pressure responds promptly to a fluid bolus administration, and the infant's vital signs shortly improve to a heart rate of 110 beats/min, blood pressure of 68/47 mm Hg without any pressors, and oxygen saturation of 100% on inspired oxygen fraction of 0.4. Chest radiography shows normal lung fields. The only finding of note on physical examination is acrocyanosis of the extremities with no obvious dysmorphic features. Pupils are round and reactive to light equally, auscultatory examination of the respiratory system reveals no adventitious sound, and abdomen is …