A nurse is planning care for a child who has a prescription for somatropin. Which of the following interventions should the nurse include to evaluate the therapeutic effect of this medication?

Choice A rationale Somatropin is a synthetic growth hormone used to treat growth hormone deficiency. The primary therapeutic effect of this medication is to promote linear growth in children. Therefore, monitoring the child's height monthly is a direct and quantifiable measure to evaluate the effectiveness of somatropin therapy and ensure that the child is achieving the expected growth velocity. Choice B rationale While thyroid function can influence growth, and growth hormone deficiency can sometimes coexist with or impact thyroid axis, evaluating the therapeutic effect of somatropin directly involves assessing growth. Monitoring thyroid function is important for overall endocrine health but is not the primary measure for the therapeutic effect of somatropin itself, assuming thyroid function is within normal limits (e.g., TSH 0.4-4.0 mIU/L, free T4 0.8-1.8 ng/dL). Choice C rationale Checking the child's sodium level regularly is not a direct measure of the therapeutic effect of somatropin. Growth hormone can influence fluid balance, but sodium levels (normal range 135-145 mEq/L) are primarily monitored for hydration status or potential adverse effects like fluid retention, not as an indicator of growth hormone's efficacy in promoting growth. Choice D rationale Measuring the child's abdominal girth is a measure of abdominal circumference, primarily used to assess abdominal distention, fluid accumulation, or changes in visceral fat. It is not a relevant parameter for evaluating the therapeutic effect of somatropin, which is specifically aimed at stimulating linear bone growth and overall somatic growth.