Diabetic ketoacidosis, hyperuricemia and encephalopathy intractable to regular-dose insulin.

BACKGROUND

Diabetic ketoacidosis (DKA) in children less than 1 year of age is a rare occurrence. Typical presentation includes a prodrome of weight loss and polyuria with subsequent presentation to medical care when acidosis becomes symptomatic.

CASE PRESENTATION

We describe an unusual case of a previously healthy infant with a 3 days' history of constipation, presenting acutely with abdominal pain, lethargy, and dehydration. On initial evaluation, our patient had profound encephalopathy, with marked tachypnea and work of breathing. Arterial blood gas revealed a pH of 6.9, pCO2 of 20 and a bicarbonate level of <5. There was profound leukocytosis (WBC 77 K/μL), hyperuricemia (uric acid 15.9 mg/dL), and evidence of pre-renal azotemia [blood urea nitrogen (BUN) 54, Cr 0.82]. Blood glucose was >700 mg/dL. Despite fluid resuscitation and insulin infusion of 0.1 unit/kg/h, which are the mainstays of therapy for DKA, her severe metabolic acidosis and altered mental status did not improve. Differential diagnosis for her metabolic derangements included inborn errors of metabolism, insulin receptor defects, toxic ingestions, and septic shock secondary to an underlying oncologic or intra-abdominal process. The patient was treated with broad spectrum antibiotics and rasburicase. She continued to have significant shock for the first 30 h of her hospital stay, requiring moderate vasoactive support. Due to her refractory acidosis and persistent hyperglycemia, insulin infusion was increased to 0.15 units/kg/h. A hemoglobin A1C obtained on the second hospital day revealed a level of 7.4 and helped to solidify the diagnosis.

CONCLUSIONS

Metabolic acidosis in an infant requires a broad differential. Rasburicase should be considered in hyperuricemia and DKA.