masscasualty

Mass casualty, in emergency management and disaster medicine, refers to an incident in which the number or severity of casualties overwhelms the response capabilities of the affected community or responders operating under normal procedures. The term is operational rather than medical, and its threshold varies by jurisdiction, resources, and infrastructure. MCI triggers changes in incident management, triage, and resource allocation. Causes include natural disasters (earthquakes, floods), major transportation accidents, mass-casualty violence, industrial incidents, and large-scale disease outbreaks; many events combine multiple factors. The central idea is that standard care cannot be delivered to every patient without adjustments.

Response to an MCI relies on structured coordination: a scalable command system, predesignated roles, and the rapid mobilization of additional personnel, equipment, and facilities. Prehospital triage aims to sort patients by urgency, directing those most likely to benefit from immediate care to appropriate treatment streams while conserving resources for the most critically injured. Hospitals activate disaster plans, expand bed capacity, and establish casualty receiving areas, while mutual aid agreements bring in outside staff and supplies. Communications, patient tracking, and interoperability between agencies are essential to prevent bottlenecks and misallocations.

Preparedness for mass casualty events emphasizes training, drills, stockpiling of supplies, and interoperable protocols. After-action reviews identify gaps and drive improvements in planning and infrastructure. Public information management is crucial to reducing panic and ensuring orderly evacuation or sheltering when needed. While MCI terminology is widely used, exact thresholds for declaring an MCI vary, reflecting local context and capabilities.