Boston C-Med System

I had been considering doing a blog post on C-Med for a while now, so when I received an email today with some questions about it, I figured now is as good a time as any.

At the most basic, C-Med is a statewide system used by ambulances to communicate patient information with the receiving hospital. The Massachusetts C-Med system is divided among five control centers throughout the state. Each system uses the same frequencies, but different PL tones. The frequencies and tones can be found here.

The basic system is made up of eight channels, each consisting of two frequencies. One frequency is used by the hospital, and the other, by the ambulance. The "hospital" side is repeated, so you will be able to hear that throughout the region, but the ambulance side can only be heard if you are within a few miles of the ambulance itself. The exception to this for Boston C-Med are Med-4 and Med-8, both of which have the ambulance side repeated on the hospital frequency. In other words, you can hear both sides of the traffic on the hospital frequency for Med-4 and Med-8. Medical helicopters also use the C-Med system, so you can often hear them on the ambulance side from a good distance away, due to their elevation.

Med-4 is the "hailing" channel, and is used to contact the control center and receive a channel assignment. A typical C-Med conversation runs something like this (for this example, we'll say you are close enough to the ambulance to receive their side clearly):

Ambulance on 463.075: Boston C-Med, Boston C-Med, this is Fallon Paramedic 104 with an ALS entry note for Brigham & Women's hospital, currently on 93 south of the city.

C-Med dispatcher on 463.075: Fallon, switch to Med-5 for Brigham & Women's.

C-Med dispatcher on 463.100: Brigham & Women's, this is C-Med, I have Fallon online with an entry note.

Hospital on 463.100: Go ahead, Fallon.

Ambulance on 468.100: Brigham & Women's, this is Fallon Paramedic 104, currently 11 minutes out from your facility with a 44 year old woman involved in a head on MVA...(Medics will give relevant details, such as vital signs, medications administered, chief complaint, etc)...any questions?

Hospital on 463.100: No questions, see you in 10 minutes in room 3.

The channel will then be released back to C-Med control. All traffic is prioritized based on the nature of the call, and can range from something as small as a BLS entry note, to as serious as a trauma case.

If you want to program Boston C-Med into your scanner, you'll only need to program the hospital frequencies  for Med-4 and Med-8. The other channels you will have to program the hospital and ambulance sides. Listen up to Med-4, and when you hear a call you are interested in, switch to the hospital side of the assigned channel, and once they acknowledge, try the ambulance side to see if you are in range.

The C-Med system also is used for medical control, for instance, if medics need a doctor's permission to administer drugs, or to stop CPR on a non-viable patient.

Corrections or contributions from EMT's, paramedics, or ER staff are more then welcome. Please post to the comments below (I'm sure I messed something up).