Case 1: Case of Lactic Acidosis in a Term Neonate

Presentation

A full term boy is delivered vaginally at 38 weeks’ gestation to a 35-year-old gravida 4, para 2 woman with unremarkable prenatal laboratory findings including negative group B Streptococcus findings. The maternal history is significant for early neonatal death of a male infant from unknown cause 7 years earlier. Pregnancy and delivery are uncomplicated. The neonate has a birthweight of 2,800 g, appropriate for gestational age, and Apgar scores of 8 and 9 at 1 and 5 minutes, respectively. He is initially feeding well in the term nursery until 6 hours after birth, when he develops respiratory distress and lethargy.

On physical examination, he is ill appearing with intermittent grunting and subcostal and intercostal retractions. He appears lethargic and hypotonic without identifiable dysmorphic features. His respiratory rate is 80 breaths/min and oxygen saturation 80% in room air. Arterial blood gas (ABG) shows a pH of 7.06, Pco₂ of 22 mm Hg (2.9 kPa), Po₂ 65 mm Hg (8.7 kPa), bicarbonate (HCO₃) 6 mEq/L (6 mmol/L), base deficit –22, and lactate 203.6 mg/dL (22.6 mmol/L). Complete blood cell count is normal and comprehensive metabolic panel reveals low serum bicarbonate of 5 mEq/L (5 mmol/L). Serum glucose level is 79 mg/dL (4.3 mmol/L). He receives 2 normal saline boluses and an acetate infusion is started. Chest …