A high school girl reveals to the school nurse that she has been engaging in self-induced vomiting as a weight-control measure. Which initial assessment should the nurse focus on with this adolescent?

A. National percentile of weight and height: Growth percentiles provide information about overall nutritional status and long-term development. However, they do not immediately determine the severity or pattern of disordered eating behaviors. An adolescent with bulimia nervosa may maintain a normal weight range, making percentile data less useful. B. Perceptions of family and social relationships: Family dynamics and peer influences are important contributing factors in eating disorders and should be explored during comprehensive assessment. However, understanding relational stressors does not immediately quantify the medical risk associated with ongoing purging. C. School grades and extracurricular activities: Academic performance and activity involvement may reflect psychosocial functioning and stress levels. While relevant in a holistic assessment, these factors do not directly assess the frequency or severity of self-induced vomiting. Immediate clinical concern is on behaviors that can cause electrolyte imbalance and cardiac complications. D. Frequency of binging and purging behaviors: Determining how often bingeing and purging occur is essential to assess severity and potential medical instability. Repeated vomiting can lead to hypokalemia, metabolic alkalosis, dehydration, and risk for cardiac dysrhythmias. The frequency and duration of these behaviors guide the urgency of medical evaluation and intervention planning.