A patient presents with type 1 diabetes mellitus and symptoms of excessive thirst, frequent urination, and fatigue. Blood tests reveal hyperglycemia and acidosis. What is the priority nursing intervention?

Rationale: A. The patient’s presentation—hyperglycemia, polyuria, polydipsia, fatigue, and acidosis—is consistent with diabetic ketoacidosis (DKA), a life-threatening emergency. The priority intervention is to restore circulating volume with IV fluids and correct hyperglycemia and acidosis with IV insulin. Rapid intervention prevents shock, electrolyte imbalances, and cerebral edema. Nursing responsibilities include frequent monitoring of glucose, electrolytes, vital signs, and urine output, while initiating therapy. B. Oral agents are ineffective in type 1 diabetes and cannot reverse DKA. Insulin therapy is required to stop ketosis, normalize blood glucose, and correct acidosis. C. Giving a high-carbohydrate meal would worsen hyperglycemia and exacerbate DKA. Nutrition is carefully managed after stabilization, not during the acute phase. D. While monitoring urine output is important for assessing fluid status and renal perfusion, it is secondary to correcting the life-threatening hyperglycemia and dehydration. Observation alone does not treat the underlying emergency.