Medical Priority Dispatch

I have written in the recent past about my frustrations with Medical Priority Dispatch (MPD), as well as the recent research that has been published pointing out its failings. The posts include Troublesome, Unformed Idea, Fair Enough and Dispatchers.

Bryan E. Bledsoe, DO, FACEP, who has made a name for himself debunking EMS myths in addition to being the author of the standard EMS text, has now weighed in on Medical Dispatch, commenting on the latest research, which shows that on half the MPD protocols, flipping a coin does a better job of correctly prediciting priority than the protocol.

Anecdote Based EMS

I agree with his conclusion: “Either the system needs to be evidence-based (that is, it works) or it should be abandoned.”

“Sixteen of the 32 protocols performed no better than chance alone at identifying high-acuity patients.”-Comparison of the medical priority dispatch system to an out-of-hospital patient acuity score.
Acad Emerg Med. 2006 Sep;13(9):954-60.
Feldman MJ, Verbeek PR, Lyons DG, Chad SJ, Craig AM, Schwartz B.


In one town where I work, someone calls 911, the town dispatcher answers, takes the information, and then kicks the call to a regional medical dispatch center to “EMD” the call. The town dispather calls us, gives us the address, nature and a priority code. “Code Three” is lights and sirens. “Code One” is no lights and sirens. We then get in the ambulance and contact the regional medical dispatch center, who provides us with “EMD” information after interviewing the caller. We basically get more info and another dispatch code. “Hot” is lights and sirens. “Cold” is no lights and sirens. We then call our town dispatcher in the event we have either been upgraded to lights and sirens or downgraded.

Yesterday one of our calls was for a person with swollen legs who had fallen a few days before, and who’s son wanted her to go to the hospital. The town dispatcher send us in nonemergency mode. The medical dispatch center upgraded us to hot because the woman had a heart history. The call was strictly BLS, nonemergency to the hospital.

We do have the ability to overrule the medical dispatch code, which is just “recommended.” I have a pretty good feel for what the call will be, particuarly if I have been to the same address before. I often just continue in the nonemergency mode if the time difference between lights and sirens and non lights and sirens will be minimal.

I think it would be interesting to do a small study comparing the accuracy of the town dispatcher, who uses their “common sense” versus the medical dispatcher who follows the algorithm.

Both have their advantages and disadvantages. I have found the medical dispatch center seems to always overtriage us by sending us “hot” if the patient has any kind of cardiac history. The town dispatchers tend to undertriage us when they send us non emergency for any kind of broken bone and overtriage us when they don’t understand what the caller is talking about just as when a G-tube comes out. They tell us to go lights and sirens. We say “ah, no.”


  • Anonymous says:

    I think it would be intersting to if someone looked at medics responce to a call when they have something like “respiratory distress” or no info. How often are we lost in tunnel vision looking for a condition that never exsisted.

  • Anonymous says:

    Since there are so few calls that a paramedic can truly make any difference between life and death, I would like to see priority dispatch calls be saved for them. These are very uncommon calls:Full arrest with a witnessed arrest.Acute asthma.Anaphylaxis.On the radio today, I heard calls go out numerous times for a code 3 chest pain from an acute car clinic to transport to the hospital. This is stupid. The clinic has more capabilities than the ambulance. Why rush to get a lower grade of care sooner? The clinic can give the baby aspirin, nitro, morphine, and do a 12 lead in the time it takes to get a crew on scene. But they don’t want to.I would like to see a study done on patient outcomes. There’s something fundamentally flawed with a system where 99% of responses to the scene at priority lead to a transfer from scene to hospital at non-priority. If it was so life-threatening as to endanger the responding crew at code 3, the patient should be so critical that they require a priority response to the hospital. How do patients fare when the ambulance is dispatched to the scene code 3, versus code 1? How do patients taken code 3 to the hospital from the scene at code 3 fare versus code 1? I suspect the difference is probably due to chance, not speed. Good procedures can eliminate the most detrimental delays. For instance, in patients within the 2 hour window for a stroke. Calling ahead, having the receiving facility get its act together to have the drugs mixed, the stroke team standing by, and the MRI open for use is much more important than shaving 5-10 minutes off the drive time.For chest pain, transmission of a 12 lead for expert interpretation is a proven way to decrease the event to cath lab time. But if a hospital has too many layers of med radio report taker to nurse to doctor to cardic cath team time, why bother rushing. It’s hurry up and wait. The biggest factors in delays to respond are not due to call priority. They are due to mobilization of a crew. I have watched crews wait in line for their food at a restaurant when they had a call. The 90 seconds saved by a priority response is offset by their wait in the restaurant. More delays happen in the delay to call 911 (half hour to an hour for chest pain. 2-6 hours for stroke symptoms.) There is the delay to prioritize the call where the dispatcher runs through their call algorithm that can be up to 2 minutes on the phone. There is the human delay in listening to the call, and getting the truck moving from the station or post. No amount of speedy driving can ever make up for these delays. It would be easier to minimize the delays earlier in the call processing than it is to over-triage calls.

  • PC says:

    Thanks for the excellent post. I fully agree with your comments.-PC

Leave a Reply

Your email address will not be published. Required fields are marked *