Final answer:
The nurse is upholding the ethical principle of confidentiality by refusing to share a patient's medical information with unauthorized personnel, thereby protecting the patient's privacy.
Step-by-step explanation:
The nurse is demonstrating the principle of confidentiality. This principle is a cornerstone of nursing and medical ethics, emphasizing the importance of maintaining the privacy of patient information.
It ensures that sensitive personal health details are not disclosed without the consent of the patient. The nurse's refusal to share the patient's medical diagnosis with a staff member from another unit is a clear application of this ethical principle, upholding the patient's right to privacy.
In contrast to the other principles mentioned, such as autonomy, which focuses on the patient's right to make informed decisions about their own health care, and justice, which involves fairness in the distribution of care, confidentiality is specifically about protecting patient information.
The principle of veracity, which refers to truth-telling, is also not the principle at hand, as it does not directly address the issue of privacy and information sharing.