A nurse is monitoring an infant who is receiving opioids for pain. Which of the following findings should indicate to the nurse that the medication is having a therapeutic effect?

The correct answer is B: Relaxed facial expression. In infants receiving opioids for pain, a relaxed facial expression indicates pain relief, as opioids work to decrease pain sensation. Bradycardia (A) and increased blood pressure (C) are common side effects of opioids and do not necessarily indicate therapeutic effect. Limb withdrawal (D) may be a reflexive response and not a reliable indicator of pain relief. Therefore, a relaxed facial expression is the most reliable sign that the medication is having a therapeutic effect.