I think you're still missing the point. It is a liability that should not be placed on EMS to document they used a field ultrasound and made a decision based on that (if it turns out to be incorrect). You are definitely right that the vast majority of trauma patients do not need a trauma center, but they do need a full eval from a physician to rule out occult trauma. It is all based on mechanism, if someone has minor trauma, they can easily go to a level 2 or 3 center. If someone has mechanism to warrant a level 1 but have a negative prehospital FAST and minimal symptoms, I don't suggest encouraging EMS to take them to a level 2/3 based on the negative US. The mentality that to sit around on scene and do an ultrasound will improve outcomes is tenuous. The role of EMS is quick stabilization and transport, that has always been shown to improve outcomes in the vast majority of pathology/trauma that is seen.
And I was under the assumption that severe abdominal pain from suspected ovarian cyst has to be evaluated for a rupture, don't OB docs get consulted for that eval/management?
Personally, I do not think US has much practical role in most EMS settings. There are smarter folks than me who feel differently though, so who knows. Theoretically, it is a great idea - all sorts of potential uses. Realistically though, using it to make accurately diagnoses takes much more training and experience than most paramedics will get with it. If I understand your posts, we basically agree on this.
That said, I think you are making the wrong arguments against prehospital US.
First, how is a poor transport decision based on US findings any more of a liability than a poor transport decision based on any other assessment findings? With US you have another tool for gathering information. What you do with that information can be either good or bad. One could turn around your very argument and say "it is a liability for EMS to not use all available technology to accurately assess their patients".
Second, mechanism of injury correlates poorly to both injury patterns and outcomes. I'd go so far as to say that using MOI in any type of decision making algorithm should be completely struck from our educational curricula and our policies/protocols. For the sake of credibility, I would never use the term MOI if your goal is to convince other clinicians.
Lastly, there is no practical difference between a ACOS-verified level 1 and level 2 trauma centers. Participation in educational and research programs are the only real differences. Clinical capabilities and resources are virtually identical. Even a level 3 has the resources to properly manage all but the subspecialty cases. So along with MOI, I would avoid relying on this terminology in your argument.
Theoretically, ultrasound is nothing but a good thing. Where it falls apart is in the nuts of bolts of having everyday paramedics learn anatomy and imaging well enough to use it accurately on all types of patients for all types scans, and then integrate those findings into a treatment plan that they likely would not have developed without the information gleaned from the scan. I think that is a very tall order, especially when compared to the risk of misdiagnosis. But it has to be about more than transport destination to be worth using it.
