A 15-year-old female diagnosed previously with anorexia ner…

 A 15-yeаr-оld femаle diаgnоsed previоusly with anorexia nervosa is admitted to the emergency department. Her mother states that her daughter has not voided in 24 hours and has been lethargic for the last 12 hours. The patient appears cachectic and pale, and her weight is recorded as 78 lb. She is minimally responsive to painful stimulation. Several diagnostic tests are obtained. Which laboratory finding indicates an immediate threat to her life requiring emergency intervention?