In the case of a mass casualty event, what should the nurse in charge of the emergency department do first?

In the event of a mass casualty, the nurse in charge of the emergency department plays a critical role in ensuring an effective response to the disaster. Activating the disaster plan is the primary responsibility because it sets into motion the pre-determined protocols designed to handle such overwhelming situations. This plan typically includes notifying the appropriate staff members, mobilizing additional resources, coordinating with emergency medical services, and organizing triage and treatment areas.

By contacting the nursing supervisor to activate the disaster plan, the nurse ensures that the entire department is prepared to manage the influx of patients and can allocate resources effectively to provide care to those in need. This step is essential for maintaining order and maximizing the efficiency of the emergency response, ultimately improving patient outcomes.

The other options, while they may seem useful, do not address the immediate need to implement a coordinated response plan. Gathering volunteers or closing the emergency department could disrupt the flow of care. Demanding EMS to reroute victims could lead to miscommunication and delay in treatment, thus undermining the emergency management efforts already in place. Consequently, activating the disaster plan is the most critical first step for the nurse in charge.