Which laboratory finding requires urgent notification when caring for a client with anorexia nervosa?

• A. Potassium 2.8 mEq/L
• B. Sodium 138 mEq/L
• C. WBC 6,000/mm3
• D. HbA1c 9.6%

Answer: (A)

Low potassium in someone with anorexia nervosa signals a medical emergency because it directly risks life-threatening cardiac and muscular complications. A potassium level of 2.8 mEq/L is far below normal and can cause arrhythmias, muscle weakness, and other serious problems if not addressed promptly. This is why urgent notification to the clinician for immediate potassium repletion and close monitoring is essential. In contrast, the sodium value is normal, the WBC is within expected limits, and while a high HbA1c suggests poor long-term glucose control, it does not pose an immediate acute risk in the context of acute care for anorexia nervosa. The key concern for urgent action is the severe hypokalemia and the arrhythmia risk it creates.