Without evidence of benefit, an intervention should not be presumed to be beneficial or safe.

- Rogue Medic

Some Research Podcasting Comments

This Eve of Christmas Eve both EMS Garage and EMS EduCast.

I Hate People: EMS Garage Episode 67, which is really much more cheerful than it sounds – and it comes with beer recommendations. One warning is that everybody seemed to be having connection problems, so we couldn’t always hear each other. this led to people talking over each other more than usual and pauses, where nobody is talking since they think someone else is still talking. these problems are minor, but do pop up occasionally. Steve Whitehead of The EMT Spot even brings a surreal dimension to the show with mime podcasting.


Understanding EMS Research: Episode 42, which may have helped to provide some understanding of research. The problem is that there is far too much to the topic to be covered in one episode. This was expected to be a brief, year end episode. A brief episode? With me on it? What were they thinking?

The other problem is believing that research can be covered effectively and briefly.

A couple of points. I point out that I think that we should start EMS education with research. Only after the students understand research, should we move on to assessment and treatment.

The big disagreement was when we were discussing some of the old discarded EMS myths, which unfortunately have not been discarded everywhere. The old rule of thumb about what pressure is indicated by what pulses, that I wrote about in A Radial Pulse Means a Pressure of At Least . . . ., where I describe the research from the BMJ from 2000[1] (not 2001 as I stated on the show). There was a bit of discussion of this and somebody mentioned relying on heart rate as an indicator of blood loss. I pointed out that beta blockers and abdominal trauma are two of the confounders of this approach.

The abdominal trauma is something that I will have to do a post on, and I do not have the studies in front of me, but there have been several papers written about surgical patients losing significant amounts of blood, but not becoming tachycardic to indicate the blood loss. Some abdominal surgery patients even became bradycardic with significant blood loss. this is an important problem, because relying on heart rate alone would did cause the continuing uncontrolled bleeding in some of these patients to be missed.

This is something important that we need to be aware of. There are many things that may mislead us in our assessments. The more that we are aware of these confounders, the less likely we are to miss a significant problem. While part of the debate was about whether this happens in the majority of abdominal trauma (it probably does not), this approach is completely irrelevant to developing an awareness of a potentially significant problem. We stress over spinal cord injuries, while the incidence of spinal cord injuries is probably much lower than the incidence of exsanguination due to abdominal trauma that is unrecognized because there is no significant rise in heart rate. The outcome may be more likely to be fatal, as well.

Anyway, my biggest disagreement was when somebody started, based on less information than I already wrote, to try to figure out why this is happening. This is a bad idea.

Why is not important!

When we started to discuss this, that this may be due to vagal stimulus, someone stated that this is just a hypothesis for a study. I don’t have any problem with using that as the hypothesis for a study, but we were not designing a study. We were providing information for educators to use to teach students.

This is exactly where medical myths come from.

The students do not need to know why something works, only that it may work. To suggest anything more than that is suggesting that we know a lot more than we do know.

It is important to know as much about the limitations of our assessments.

It is not important to know why, until after we have a lot of information to support that idea.

Look at where the EMS myths started from. Somebody started explaining why something was happening, or maybe they were only wondering about the cause. Educators got a hold of the idea, and rather than say, I don’t know why, some gave an explanation that was repeated enough to become a myth. A myth that is almost impossible to get rid of, because people want certainty.

Certainty is nice, but it is a problem.

The only certainty in medicine is that we do not know as much as we think we know.

When we start taking explanations for granted, we find that somebody read too much into an observation, or a bunch of observations, or read too much into a study, or a bunch of studies.

This is the same thing that leads the general public to distrust science. We have research that provides limited information, but somebody decides to explain that limited information. If you want to bet on something that is almost a sure thing, here is what you should do.

Bet that the explanation is wrong.

This does not mean that the science was bad, or that the science was wrong, or that the study was not done well, et cetera. It means that somebody took a look at some science and decided to create some fiction, because they assume that they know what they are doing.

The safe bet certain bet is that the explanation is wrong.

The certainty in science and medicine is that our explanations will be wrong. These erroneous explanations will create distrust of science and medicine. these will not be the fault of the researchers, but of those explaining the research.

When we create explanations, we create a narrative – a story. We should start out with, Once upon a time . . . , or something similar, but we don’t. I have discussed this problem with narrative fallacy further in the links listed below. I will write about this more, because this is important.

I do not mean to put down anyone on the show. This is a problem that is almost universal. One of the reasons that it is so common, is that it is natural for us to explain things with stories. When life was simpler, that may have been effective. When the life of someone else is in our hands, we need to be better than that.

Narrative Fallacy –

Narrative Fallacy I

How did this happen? – Research

Narrative Fallacy II

CAST and Narrative Fallacy

C A S T and Narrative Fallacy comment from Shaggy

Some Research Podcasting Comments

Shaggy Comments on Some Research Podcasting Comments.

Spine Immobilization in Penetrating Trauma: More Harm Than Good?

EMS EdUCast – Journal Club 2: Episode 43

Education Problems, Autism, and Vaccines


[1] Accuracy of the advanced trauma life support guidelines for predicting systolic blood pressure using carotid, femoral, and radial pulses: observational study.
Deakin CD, Low JL.
BMJ. 2000 Sep 16;321(7262):673-4. No abstract available.
PMID: 10987771 [PubMed – indexed for MEDLINE]

Free Full Text . . . . Free PDF

Prepublication History of Manuscript



  1. […] Research Podcasting Comments Fri, 25 Dec 2009 15:51:00 +0000 By Rogue Medic Leave a Comment This Eve of Christmas Eve both EMS Garage and EMS […]

  2. […] results wander into narrative fallacy, which I have written about here, here, here, here, here, here, here, here, here, and […]

  3. […] the comments to Some Research Podcasting Comments, Shaggy wrote, I am beginning to think our definition of “why” in the educational arena […]

  4. […] Too often we base our treatments on conclusions drawn from research that has been spun into a tale to explain why something works. This is narrative fallacy. I explain more in Some Research Podcasting Comments. […]

  5. […] Too often we base our treatments on conclusions drawn from research that has been spun into a tale to explain why something works. This is narrative fallacy. I explain more in Some Research Podcasting Comments. […]