A nurse is working in the emergency department when a mass casualty incident occurs. Multiple patients arrive simultaneously with varying degrees of injuries. What is the nurse's first priority in this situation?

In mass casualty incidents, the immediate priority is implementing the disaster management plan and initiating triage protocols to systematically assess and categorize patients based on injury severity and treatment urgency.

Mass casualty incidents require the immediate activation of systematic emergency response protocols to ensure optimal patient outcomes and resource utilization in overwhelming situations where the number of patients exceeds normal capacity. The disaster management plan provides a structured framework for coordinating care in these situations.

Triage is central to mass casualty management, a process of rapidly assessing and classifying patients based on injury severity, survivability, and resource requirements. The START (Simple Triage and Rapid Treatment) system commonly categorizes patients into four groups: Immediate (red tag) - life-threatening injuries requiring immediate intervention, Delayed (yellow tag) - serious but stable injuries, Minor (green tag) - ambulatory injured, and Deceased/Expectant (black tag) - unsalvageable conditions.

Implementing the disaster plan first ensures that appropriate communication channels are established, proper personnel are notified, and resources are allocated efficiently. This systematic approach prevents chaos and ensures that the most critical patients receive priority care while saving as many lives as possible with available resources.

The disaster management plan also coordinates with other departments, activates additional staff through established call-in procedures, and ensures proper documentation and family notification processes are in place. Without this initial phase, individual actions such as trauma room preparation or supply gathering may be inefficient or misdirected, potentially compromising patient care and safety.

Understanding the Priority in a Mass Casualty Incident

When a mass casualty incident (MCI) occurs, the operational paradigm of the emergency department shifts dramatically. The standard patient care model, which prioritizes the most critically ill or injured individual, is temporarily replaced by a disaster management model. The immediate, overarching goal becomes doing the greatest good for the greatest number of casualties. This is achieved through a systematic, coordinated response that begins the moment a notification is received.

The correct first action is to implement the hospital's disaster management plan and initiate triage protocols. This is not merely an administrative step; it is the foundational clinical and operational command that activates all subsequent actions. A hospital's disaster plan, often termed a "Code Orange" plan, is a pre-established framework designed to align the facility's response with international guidelines for surge capacity and resource allocation [1]. Activating this plan is the single action that authorizes and orchestrates the entire response, including the very steps listed in the other options. Without this activation, preparing a trauma bay, calling in staff, or gathering supplies are isolated, uncoordinated acts that can lead to confusion, resource misallocation, and ultimately, poorer patient outcomes.

The Central Role of Triage in an MCI

Initiating the triage protocol is inseparable from activating the disaster plan. In an MCI, triage is fundamentally different from the routine Emergency Severity Index (ESI) triage used daily. The goal shifts from identifying the sickest patient first to rapidly sorting all casualties into categories based on the urgency of their need for life-saving intervention and their potential for survival, given the available resources. This process directly addresses the core challenge documented in MCI responses: managing an overwhelming surge where patient needs exceed immediately available resources [2].

A simulation-based program for a rural hospital demonstrated that a key learning objective for effective MCE response is the ability to transition seamlessly to this specific triage mindset, ensuring that team members understand their roles within a pre-defined, coordinated system [3]. The triage protocol provides the critical situational awareness needed to determine how to best use the trauma bay, which staff to call, and what supplies to gather. For example, the triage officer’s rapid assessment will identify patients requiring immediate life-saving interventions, who will then be directed to the trauma bay, making the preparation of that bay a meaningful and informed action rather than a speculative one.

Why the Other Options Are Not the First Priority

The remaining options are all vital components of the MCI response, but they are dependent actions that flow from the initial activation of the disaster plan and triage protocols.

- Preparing the trauma bay is a critical task for receiving the most critically injured. However, until a formal triage process is underway, it is impossible to know how many critically injured patients there are, the nature of their injuries, or if the trauma bay’s resources would be better utilized for a higher volume of moderately injured patients who can be stabilized quickly. The disaster plan dictates how clinical space is repurposed and expanded to create surge capacity [2].
- Contacting additional nursing staff is a core element of the disaster plan’s personnel recall procedure. A staff recall is typically triggered automatically by the plan's activation, often through a designated communication system. A single nurse attempting to call colleagues individually is inefficient and bypasses the structured chain of command essential for a coordinated response. An assessment of healthcare workers' knowledge, attitudes, and practices regarding MCI preparedness highlights that a well-known, documented plan is what ensures staff know their roles and how they will be mobilized [1].
- Gathering emergency supplies and medications is a logistical necessity. However, the specific type and quantity of supplies needed are dictated by the triage categories of the incoming patients. The disaster plan designates how and from where supplies are mobilized, often involving the central supply department to deliver pre-packed disaster caches to designated areas. Acting independently to gather supplies risks creating a redundant stockpile in one area while another critical zone is left without.

The sequence of response is therefore hierarchical. The activation of the disaster management and triage system is the cognitive and organizational first step that informs, directs, and synchronizes all physical preparations, staffing decisions, and resource allocation. This systematic approach is the cornerstone of transforming a chaotic situation into a structured, efficient, and life-saving operation.