mrcem2-0674

mrcem2-0674

A 10-year-old boy is brought to the Emergency Department by his parents with a history of thirst and increased frequency of urination. He is also complaining of severe abdominal pain, and his parents are concerned he may have a urinary tract infection. His condition has deteriorated over the past few hours, and he is now lethargic and slightly confused. His observations are as follows: HR 145, RR 34, SaO2 97%, temperature 37.5°C. On examination, he has dry mucous membranes, and his capillary refill time is 4 seconds. Cardiovascular and respiratory system examinations are both unremarkable. His abdomen is tender across all quadrants with voluntary guarding is evident. The paediatric nurse has performed urinalysis, which has revealed a trace of leukocytes and protein with 3+ ketones and glucose.
What is the SINGLE most likely diagnosis?