Final answer:
The nurse should listen to Mr. Mathis' concern attentively, provide relevant information or take actions to address it, and involve him in care decisions.
Step-by-step explanation:
When responding to Mr. Mathis' concern, the nurse should employ patient-centered communication, listen attentively to understand the nature of his concern, and provide information or take relevant actions to address the issue. It is vital for the nurse to establish rapport, offer reassurance when appropriate, and involve Mr. Mathis in decision-making regarding his care. If the concern is clinical, the nurse may need to perform an assessment, review medical orders, or consult with other healthcare team members to provide correct and comprehensive care.