Hyperosmolar hyperglycemic state with severe hypernatremia coexisting with central diabetes insipidus: A case report and literature review.

Diabetes insipidus is characterized by polyuria and polydipsia, often resulting from central or nephrogenic causes. In diabetic emergencies, hyperosmolar hyperglycemic state (HHS), severe hypernatremia, and ventricular fibrillation are life-threatening conditions that require prompt intervention. This report describes a 47-year-old male with poorly controlled diabetes mellitus, who developed coma, excessive thirst, polyuria, hyperglycemia (47.29 mmol/L), hypernatremia (195.6 mmol/L), and plasma hyperosmolality (385 mOsm/kg). Despite fluid resuscitation and insulin therapy, refractory hypernatremia persisted, leading to a diagnosis of central diabetes insipidus (CDI). The patient also developed ventricular fibrillation, which was managed with defibrillation. Concurrently, desmopressin and blood purification were administered to address CDI and severe hypernatremia. This case emphasizes the importance of considering CDI when polyuria persists despite glucose control. The occurrence of ventricular fibrillation underscores the necessity of continuous cardiac monitoring in the context of hypovolemia and severe electrolyte imbalance. We propose that diabetes mellitus-related vascular injury impairs blood flow in the hypothalamus-pituitary tract, disrupting arginine vasopressin synthesis and secretion, contributing to CDI in poorly controlled diabetes mellitus.