Mixed Presentation of Hyperglycemic Hyperosmolar State and Diabetic Ketoacidosis in a Pediatric Patient: a Case Report and Literature Review.

The coexistence of diabetic ketoacidosis (DKA) and hyperglycemic hyperosmolar state (HHS), known as mixed hyperglycemic crisis, is a rare but potentially fatal metabolic emergency in pediatrics, and is frequently underrecognized because it is misclassified as isolated DKA. It carries a higher risk of complications than either entity alone, particularly in patients with complex comorbidities. We describe the case of a 16-year-old female with myelomeningocele, neurogenic bladder, obesity, and insulin resistance, who had self-discontinued treatment with metformin, atorvastatin, and allopurinol one year prior and presented with sudden neurological deterioration. Initial workup revealed extreme hyperglycemia (1,777 mg/dL), severe hyperosmolarity (431 mOsm/kg), decompensated metabolic acidosis (pH 7.13), and positive urine ketones (+++), consistent with a mixed DKA-HHS presentation. She subsequently developed septic shock of urinary origin, acute kidney injury, and acute pancreatitis (lipase 3,911 U/L). Despite intensive management guided by International Society for Pediatric and Adolescent Diabetes-ISPAD recommendations, she progressed to refractory shock and multiorgan failure, dying within 48 hours of admission. To the best of our knowledge, this represents one of the most extreme metabolic derangements reported in pediatric mixed hyperglycemic crisis. The convergence of extreme hyperosmolarity, concurrent sepsis, and structural comorbidities created a lethal risk phenotype in which sepsis, rather than the degree of metabolic derangement alone, appeared to determine the fatal outcome. Early recognition and an individualized therapeutic approach are essential to improve outcomes in vulnerable pediatric patients.