A 35-year-old male is brought to the emergency room by his wife. She states that he’s had the “stomach flu” for the past 2 days with severe diarrhea and vomiting. During the interview, the patient tells the nurse that he’s weak and fatigued. He also complains of lightheadedness, muscle spasms, as well as numbness and tingling in his extremities. The nurse is the first to review the laboratories ordered by the practitioner. Based on the patient’s history and symptoms, which of these results should the nurse report immediately to the ordering practitioner?