Case 2: Tachypnea and Persistent Neutropenia in a Term Infant

A male newborn is transferred to the neonatal intensive care unit (NICU) for management of respiratory distress and in utero illicit drug exposure. The mother is gravida 3, para 2002 whose previous child was conceived by a different father. Family medical history is not significant. The pregnancy was complicated by limited prenatal care, maternal incarceration, Escherichia coli urinary tract infection, and use of amphetamines, opiates, and tobacco. The infant was delivered at 37 weeks’ gestation in an ambulance en route to the hospital. Resuscitation at birth included chest compressions and positive pressure ventilation. His course in the NICU is remarkable for persistent mild tachypnea necessitating positive pressure ventilation via nasal cannula until age 14 days. The cause of his respiratory distress is unknown, although he has a narrow thorax apparent on physical examination and radiography (Figure 1). Figure 1. Chest radiograph of the patient at age 3 days reveals a narrow thorax. An initial sepsis evaluation revealed thrombocytopenia (platelet count, 60 × 103/μL [60 × 109/L]), leukopenia (white blood cell count, 3,700/μL [3.7 60 × 109/L]), and neutropenia (absolute neutrophil count [ANC], 703/μL [0.7 × 109/L]). The thrombocytopenia responds to platelet transfusion with subsequent normalization throughout the hospital stay. The neutropenia, however, persists. The patient has variable and usually nonsustained response to administrations of granulocyte colony-stimulating factor …