A nurse is caring for a client with diabetes insipidus (DI). Which data warrants the most immediate intervention by the nurse? Reference Range: Sodium [136 to 145 mEq/L (136 to 145 mmol/L)]

Choice A reason: A serum sodium level of 185 mEq/L is critically high and indicates severe hypernatremia, which can lead to neurological impairment, seizures, and death. Immediate intervention is required to correct fluid balance and prevent complications. Choice B reason: Dry skin and poor turgor suggest dehydration, which is concerning but not as immediately life-threatening as severe hypernatremia. Choice C reason: Tachycardia may reflect dehydration or stress but is not as urgent as the dangerously elevated sodium level. Choice D reason: Polyuria and thirst are hallmark symptoms of DI but are expected findings. They do not require emergency intervention unless accompanied by critical lab values.