Final answer:
A registered nurse must inform superiors, document the situation, ensure a handover if possible, and make arrangements for continuity of patient care before leaving their unit due to understaffing.
Step-by-step explanation:
Before leaving the unit, a registered nurse (RN) must take steps to ensure patient safety and adhere to the professional standards of nursing practice. This would involve informing their supervisor or the charge nurse of the situation, documenting the conditions and reasons for their intended departure, and ensuring that the handover to any arriving staff is completed if possible. The nurse must also attempt to make arrangements for safe continuity of patient care, even if that means contacting higher-level administration or seeking legal advice.