An adolescent diagnosed with an eating disorder presents to the emergency department (ED) after losing consciousness during a marching band performance. After reviewing the client's laboratory data, which finding indicates a need for hospitalization?

A. Hypokalemia: Low potassium is a dangerous complication of eating disorders, especially in those who purge. It can cause cardiac arrhythmias, muscle weakness, and potentially fatal cardiac arrest, making it a critical finding that requires immediate hospitalization. B. Hyperphosphatemia: Elevated phosphate levels are not typically associated with eating disorders. In fact, patients are more likely to experience hypophosphatemia, particularly during refeeding, which poses risks but is not suggested in this case. C. Hypoglycemia: Low blood sugar can occur in eating disorders due to poor caloric intake and can cause dizziness, weakness, or fainting. While it requires treatment, it is less immediately life-threatening than severe hypokalemia. D. Hypermagnesemia: Elevated magnesium is not a common finding in eating disorders. Electrolyte disturbances such as hypokalemia, hyponatremia, and hypophosphatemia are more frequently seen and clinically significant.