Final answer:
The priority nursing action would be to ensure personal safety by leaving the room.
Step-by-step explanation:
When caring for a client in an inpatient mental health facility who gets up from a chair and throws it across the day room, the priority nursing action would be to ensure personal safety. This means that the nurse should leave the room to avoid potential harm. While documenting the incident and informing the charge nurse later is important, the nurse's immediate priority should be to maintain personal safety.
Calling for assistance from other staff members can also be a helpful action to manage the situation, but it may not be the priority in this case. Restraint should only be used as a last resort and in accordance with facility policies.
Keywords: inpatient mental health facility, priority nursing action, personal safety, document incident, inform charge nurse, call for assistance, restrain client.