http://en.wikipedia.org/wiki/Incident_commander

Incident Commander – oversees all operations at the incident.[2]
usually one of the first officers on scene.
assessment of the scene.
establish command as well as command centre.
request required resources.
initiates triage.

MIO - medical incident officer is olvasható egy brit honlapon
http://www.hpa.org.uk/webc/HPAwebFile/HPAweb_C/1194947395416

szinoníma két lehetőség

Assessing the scene

An ambulance is likely to be at the scene at an early stage. If it is a major incident, the crew should not get involved in treating individuals but they need to assess the situation and report back to control. Survivors are better served by an informed and co-ordinated response than by instant treatment of a few on arrival. There will be an Ambulance Incident Officer (AIO) who is the senior crew member who is in charge until a more senior officer arrives. His tasks include:

az AIO érkezik elsőnek a helyszínre és tőle átveheti az irányítást a MIO, de szerintem a MIO és az AIO lehet ugyanaz a személy is
Assessing the scene.
Declaring a major incident and giving a situation report (SITREP).
Deciding where to locate the Control Point, Casualty Clearing Station (CCS), and Ambulance Parking Point, as well as planning ambulance entry and exit routes.
The AIO is in charge of communication with all health service personnel on the scene.
The AIO discusses with the chain of command the need for additional support, such as a Medical Incident Officer (MIO) on scene, the Medical Emergency Response Incident Team (MERIT) and additional equipment.

szóval nem körbelövöldözni akarom a lehetőségeket, hanem szerintem ezek szinonímák és országonként vagy helyzet szerint változik