A nurse is working in the emergency department during a mass casualty incident involving a chemical exposure. Which action should the nurse take first when receiving potentially contaminated patients?

In mass casualty incidents involving chemical exposure, decontamination must be the first priority to prevent secondary contamination of healthcare workers and the facility. This includes establishing decontamination areas, ensuring proper PPE is available, and having decontamination protocols ready before any potentially contaminated patients arrive.

In mass casualty incidents involving chemical exposure, immediate implementation of decontamination procedures is necessary to protect healthcare workers, other patients, and the medical facility from secondary contamination. The fundamental principle in chemical exposure emergencies is to prevent the spread of contamination before providing medical treatment.

Decontamination procedures must be established before patients arrive and include several critical components. First, a designated decontamination area should be set up in a separate zone outside the main emergency department, equipped with appropriate drainage and ventilation. Healthcare workers must wear appropriate personal protective equipment (PPE), including chemical-resistant protective clothing, gloves, boots, and respiratory protection, before coming into contact with patients.

The decontamination process typically involves removing all of the patient's clothing and jewelry, followed by thorough washing with copious amounts of water or specific decontamination solutions depending on the chemicals involved. This process must occur before the patient enters the main treatment area to prevent contamination of the facility and exposure to other patients and staff.

Secondary contamination is a significant risk in chemical exposure incidents. Even small amounts of chemicals remaining on a patient's skin, hair, or clothing can cause serious health effects for healthcare workers and other patients. Studies have shown that if proper decontamination procedures are not followed early on, medical facilities can become contaminated, requiring extensive cleaning.

The correct answer prioritizes safety through the prevention of secondary contamination, which is fundamental to emergency preparedness and response protocols. This approach protects the healthcare team's ability to provide ongoing care and prevents the incident from spreading beyond the original victims.

Understanding the Priority: Safety and Decontamination First

In any mass casualty incident involving hazardous materials (HazMat), the overarching principle that guides all actions is the protection of the healthcare team, the facility, and other patients from secondary contamination. If a chemically contaminated patient enters the emergency department without prior decontamination, the substance can off-gas, spread through physical contact, and incapacitate staff, effectively shutting down the emergency response and turning the hospital into a secondary incident site. The nurse’s first action must therefore be to establish a secure perimeter and verify that decontamination processes are operational before the patient physically arrives at the hospital entrance.

Why the Other Options Are Not the First Priority

- Option 1 (Immediately begin triage assessment): Triage is a critical step, but it must occur after decontamination. Performing an assessment on a contaminated patient exposes the nurse to the unknown chemical, risking acute injury. The concept of a "golden rescue window" for decontamination, as highlighted in nuclear and chemical medical rescue research, emphasizes that cutaneous contamination is the primary route of ongoing injury and must be halted immediately to mitigate harm ^[4]. Triage before decontamination bypasses this life-saving window and endangers the triage officer.

- Option 2 (Prepare isolation rooms): While isolation is part of the overall response, simply placing a contaminated patient in a room does not stop the chemical exposure. The patient continues to absorb the agent, and the room itself becomes a contaminated "hot zone." Standard hospital ventilation is not designed for chemical incidents, and the act of moving a contaminated patient through the department spreads the hazard. The priority is to remove the contaminant at the point of entry, not to contain it inside the facility.

- Option 3 (Contact the poison control center): Information gathering is essential for definitive treatment, but it is a secondary action. The immediate, time-sensitive need is to stop the ongoing chemical injury. Delaying decontamination to wait for agent-specific protocols allows the chemical to continue penetrating the skin and causing systemic toxicity. The initial management of a patient exposed to an unknown chemical is always gross decontamination, which is universally effective regardless of the specific agent ^[4].

The Clinical Rationale: A Systems-Based Approach to CBRN Incidents

Hospital preparedness for chemical, biological, radiological, and nuclear (CBRN) incidents is built on a tiered system of readiness, and decontamination is the foundational operational capability. A study developing a hospital preparedness assessment tool for CBRN incidents in resource-limited settings identified decontamination capacity as a core domain of operational readiness . This reflects the universal standard that no patient should cross from the "hot zone" (contaminated area) into the "cold zone" (clean treatment area) without undergoing decontamination.

The process of decontamination directly addresses the mechanism of injury. In chemical exposures, the agent remains on the skin and clothing, acting as a reservoir for continued absorption. Research on human decontamination agents explains that prompt and effective decontamination is a crucial prerequisite for mitigating harm because it physically removes this reservoir, interrupting the primary route of acute injury and internal exposure ^[4]. For the nurse receiving the first ambulance, ensuring that the decontamination tent, water supply, and personal protective equipment (PPE) are set up and that trained personnel are in position is the single most impactful action to reduce morbidity and mortality for all incoming patients.

Furthermore, simulation-based training, such as tabletop exercises, consistently reinforces that the first step in a CBRN scenario is scene safety and preparation of decontamination assets . This training ingrains the sequence: first, protect yourself and your facility; second, decontaminate the patients to stop the injury; and third, begin medical assessment and treatment. By ensuring decontamination procedures are in place before the patient’s arrival, the nurse executes the critical step that enables all subsequent care to be delivered safely and effectively.