Case 39-2001

Abstract

A two-day-old girl was admitted to the hospital because of persistent hypoglycemia.The infant had been born at 34 weeks' gestation to a 35-year-old mother after an uneventful pregnancy. The birth weight was 3510 g. The Apgar score was 4 at one minute and 7 at five minutes. There was no maternal history of gestational or insulin-dependent diabetes mellitus. The blood glucose level, measured at the hospital where the child was born, was less than 10 mg per deciliter (0.6 mmol per liter). An umbilical arterial catheter was inserted, and a bolus of glucose was given, followed by a 22-ml infusion of glucose, for one hour, and then by a 10-ml infusion, given hourly. At three hours, the glucose level was 24 mg per deciliter (1.3 mmol per liter). During the next several hours, repeated boluses and a continuous infusion of glucose were administered; the glucose level ranged between 21 and 34 mg per deciliter (1.2 and 1.9 mmol per liter). At 14 hours, a seizure occurred, and the dose of glucose was increased.The results of laboratory tests (except for glucose and insulin), performed at 12 hours and subsequently, are shown in Tables 1, 2, and 3. During the next few hours, the glucose level varied; a level of approximately 60 mg per deciliter (3.3 mmol per liter) was common, but the level repeatedly dropped to 25 mg per deciliter (1.4 mmol per liter). The infant had six seizures, each of which lasted for 25 to 30 seconds and was characterized by facial grimaces, twitching of the left eye, and a cat-like scream, followed by tonicclonic movements of the arms and legs and lethargy of a few minutes' duration. The oxygen saturation fell to 80 to 90 percent during these episodes. Phenobarbital was administered after the third seizure.Two hours later, a 45-second episode of apnea responded to continuous positive airway pressure. Shortly after birth, the infant had been placed in a hood that provided 40 percent oxygen; between seizures, the oxygen saturation ranged from 95 to 100 percent. Ampicillin and gentamicin were administered. On the second day of life, the infant was transferred to this hospital. An umbilical venous catheter was inserted en route.The infant had two normal siblings; the third sibling had cerebral palsy.The temperature was 36.7°C, the pulse was 144, and the respirations were 60. The mean arterial pressure was 45 mm Hg. The weight was 3460 g.On examination, the infant had a plethoric appearance and was large for her gestational age. The Moro and grasp reflexes were present; there was no sucking reflex.The urine was normal. The phenobarbital level was in the therapeutic range. The insulin level was 105.5 µU per milliliter (757.0 pmol per liter). A thoracic radiograph showed hyperexpanded lungs with possible pneumonia.The glucose infusion was increased to 90 mg per kilogram of body weight per minute at a concentration of 22.5 percent glucose. Ampicillin and gentamicin were continued, and a central venous line was inserted. The ionized calcium level was normal.Hypoglycemia persisted. By the second hospital day, the...