A female infant was delivered spontaneously at 32 weeks' gestation after several weeks of amniotic fluid leak. The birth weight was 2100 g. The Apgar score was 9 at 1 and 5 minutes. Moderate respiratory distress was treated effectively with 10 hours of assisted ventilation. At age 10 days, an episode of bradycardia and apnea led to further investigation, which revealed leukopenia, thrombocytopenia (36×109/L), and a serum C-reactive protein level of 0.06 g/L. Results of a lumbar puncture were normal. Cefotaxime (50 mg/kg of body weight every 8 hours) and netromycine (3 mg/kg of body weight every 18 hours) therapy was begun for management of Klebsiella pneumoniae—related septicemia. Development of a profound metabolic acidosis required ventilatory support, and, because of hypotension, fresh frozen plasma, albumin, and vasopressors (dopamine, dobutamine, and naloxone) were administered. The infant became anemic (hemoglobin level, 90 g/L) and developed generalized seizures, jerky nystagmoid eye movements, and a mydriatic left pupil.