A nurse is caring for a child with a history of vomiting, diarrhea and dehydration, who is receiving IV fluids to correct dehydration. Which of the following laboratory values should be the priority for the nurse to follow up with the pediatrician?

Rationale: A. Potassium 2.8 mEq/L indicates hypokalemia, which is concerning and requires monitoring and replacement, but it is not as immediately life-threatening as severe hypernatremia. B. Urine specific gravity 1.020 is within normal limits and does not indicate a critical issue. C. Sodium 165 mEq/L represents severe hypernatremia, which can lead to neurological complications such as seizures or cerebral hemorrhage. This is the priority laboratory value requiring immediate intervention. D. Hematocrit 62% suggests hemoconcentration from dehydration, which is important to monitor, but correction of hypernatremia takes precedence to prevent acute complications.