An effectively managed emergency response rests on an established triage system. Triage is a French word that means $$to select.$$ Specially trained personnel follow established triage guidelines to assess patients$$ conditions and determine where they should be sent and what treatment they should receive.

Triage systems are not just for major natural emergencies but are also used in the emergency department when multiple patients need medical care. An example is a bus accident with multiple passengers or a passenger train that derails sending multiple victims to the emergency department. When there are multiple victims, the available services can be overstrained, so the triage personnel must determine who to treat first, what lab or diagnostic tests receive priority, what procedures to perform immediately, and who to send to surgery. They continually reassess patients who are waiting for services to determine if their condition has changed and if their priority needs to be updated.

A less obvious triage system is in place at all times in the emergency department. For example, there may be a patient waiting to be seen for an earache or another who fell off a bike and may have a possible broken collarbone. Then a third patient arrives with complaints of chest pain and may be having a heart attack. The patient with the potential heart attack will be seen first, because his or her need is more urgent and lack of immediate care could lead to death.