Case 1: A Medically Complex 10-month-old Boy with Lethargy

Presentation

A 10-month-old boy status-post hematopoietic stem cell transplant for leukemia, with type IV renal tubular acidosis secondary to cyclosporine and resolved hypertension, presents to the emergency department with lethargy. He had been difficult to awaken since this morning. His family denies fever, other symptoms suggestive of infection, or trauma. Current medications include cyclosporine, sulfamethoxazole/trimethoprim, and citric acid. His family denies any possibility of unintentional toxic ingestion.

On examination he is lethargic, with a Glasgow Coma Scale score of 10 (eye opening = 2, verbal = 3, motor = 5). His temperature is 98.6°F (37°C), heart rate is 102 beats/min, respiratory rate is 22 breaths/min, and blood pressure is 84/35 mm Hg. The head is without signs of trauma. Pupillary examination is notable for miosis (2mm-1mm) bilaterally. A nasogastric tube is affixed to the right cheek. There is no meningismus. The chest, cardiac, and abdominal examination results are all within normal limits. The neurologic examination is notable for lethargy but without other focal deficits.

A complete blood cell count with a differential count reveals a white blood cell count of 5.6/μL (0.01×10⁹/L) (71% neutrophils), a hemoglobin level of 8.0 g/dL (80 g/L), and a platelet count of 129×10³/μL (129×10⁹/L). Serum chemistry values (including calcium, magnesium, and phosphorous) are normal aside from a bicarbonate level of 19 mEq/L (19 mmol/L). A urine toxicology screen is negative for opiates, cannabinoids, benzodiazepines, barbiturates, and cocaine. Findings from …