Un exercice simulé de préparation à la gestion médicale des urgences radiologiques

The University Health Network’s Medical Emergency Radiation Incident Team (MERIT) provides 24-hour emergency service for radioactively contaminated and/or irradiated casualties. MERIT runs simulated radiological accident scenario exercises at Toronto Western Hospital’s Emergency Department to evaluate team response. A drill was conducted on October 13, 2023, to test MERIT response capabilities.

Background

MERIT comprises University Health Network (UHN) staff, emergency department physicians, nurses, and radiation safety specialists from the clinical areas that are required to maintain updated knowledge and technical skills within the field of medical management of radiation injuries.

The team supports trauma-contaminated casualties from Ontario Power Generation nuclear sites, including Pickering and Darlington, but can be called upon by other nuclear facilities and organizations using or processing radioactive materials. The team is activated through CritiCall Ontario (which provides services to physicians, hospitals, and other healthcare stakeholders to ensure Ontario patients can access urgent and emergent care as close to home as possible), but may also be activated through the Provincial Nuclear Emergency Response Plan and corresponding Radiological Health Response Plan.

Established in 1992 as the Radiation Trauma Unit, MERIT is a provincially supported program through the Ministry of Health and is implemented as part of the Provincial Nuclear Emergency Plan.

MERIT response in a simulation exercise

At around 4:00 am on October 13, police received a distress call from a security guard at an industrial manufacturing plant. When they arrived at the plant, police officers found an unidentified man vandalizing the facility’s equipment.

The man was talking to himself and using a crowbar to damage property. During his destructive episode, he received cuts and scrapes when he broke open a source of Strontium-90. Police officers restrained the man and called for emergency medical services (EMS) to transport him to a nearby community hospital. Fortunately, this was only a simulated incident.

When the hospital discovered that the patient had contaminated radiological injuries, they initiated a MERIT response. Each responding member of the team—which consists of a physician, a radiation safety specialist (RSS), and a decontamination nurse—plays a crucial role in staff safety and patient care.

The team physician leads the response. They

• notify the team,
• coordinate patient arrival, and
• direct patient medical assessment, decontamination, treatment, and countermeasures.

The RSS and site security

• prepare the area for patient transfer from EMS,
• issue responder dosimetry, and
• perform radiation risk assessment and contamination surveys.

The decontamination nurse leads

• patient decontamination,
• biological sampling, and
• other medical supports.

As part of the simulation, a tarpaulin was set up at the emergency entrance and a pathway to the designated emergency room was prepared. The radiation emergency area (REA) was prepared for patient decontamination and treatment. Additional medical and surgical supplies required for treating traumatic injuries were brought in. MERIT responders put on full personal protective equipment (PPE), including Tyvek suits, booties, and face protection.

As part of any MERIT response, decontamination is conducted as needed. In cases of life-threatening conditions, the patient is brought directly from the ambulance into the REA and transferred to the decontamination table. Life-threatening medical management and traumatic injuries take precedence over radiation-related injuries.

Within the REA, clothing is cut away and set aside. Sheets or blankets, along with clothing, are rolled to contain any radioactive material. They are then placed in designated plastic bags and removed. Samples are collected to determine the type and quantity of radioactive contamination.

Unstable wounds are uncovered, stabilized, and covered with leakproof dressing until they can be decontaminated. The order of decontamination is typically wounds, orifices, high-level skin areas, and low-level skin areas. Standard wound treatment protocols are generally followed, with the first decontamination attempt often removing over 90% of the contamination.

Once the patient is medically cleared to leave the REA, the patient is transferred to a clean stretcher. During the cleanup phase, the RSS conducts a survey of the area, removing all contaminated articles. Decontamination liquid waste and disposable solid waste are labelled. A final survey and wipe testing of the REA and ambulance, as well as the staff, is performed.

In the simulation on October 13, actual Strontium-90 check sources (no spoilers to responders) were identified on the patient by the RSS as a beta emitter. Additional information came in shortly after from the incident site to confirm this. Upon medical direction, calcium gluconate was administered for suspected internal contamination.

Prior to the simulation exercise, an educational instrumentation in-service had been provided to the team, and a debrief was held to close the simulation activities.

Simulations like these help ensure we are adequately prepared for potential emergencies. This is increasingly important because of Ontario’s expanding nuclear power reactor fleet and increased use of radioactivity in agriculture and other industrial settings.