No doubt that EMS typically sees things as more emergent than our hospital colleagues. A product, I think, of both our training (we're trained for emergencies, so we see emergencies) and our lack of training (we often don't have the education or experience to "take it easy" and understand that there's no bogeyman lurking here).
Nevertheless, in pathologies for which (by the best evidence and physiological reasoning available) there's essentially a continuous positive relationship between time and risk/injury/mortality, it makes sense to me to move as quickly in all respects as you can do without endangering anybody, compromising necessary life support, or losing control of the situation. The only purpose to placing specific time milestones on it is to simplify guidelines or to pick an arbitrary goal.
In other words, if sooner is better for a STEMI (or whatever), it's not "get there under 90 minutes and you win," it's "80 is better than 90, 70 is better than 80, et cetera, all else being equal." I realize it's easier to set concrete goals to check off, but that rarely makes much sense when you think about the human body.
For what improvement in time-to-care would you find it worthwhile to walk faster? Clearly not five minutes. Ten? Twenty? Would you drive 2 MPH faster if I gave you thirty minutes? Would you listen to Taylor Swift the whole way if I gave you forty? I assume you're not all-or-nothing on this, so it's clearly a matter of scale.
The bolded part I think you are correct about, but I think the relationship is far from linear. If 95% of damage to heart tissue is done in the first hour of a STEMI and the remaining 5% is done over the next 4 hours, and this guy has been having chest pain for an hour, is it really worth saving 5 minutes to save .3125% of the tissue....considering the risk of driving code-3?
I think many people look at a situation and say, well we got him there really fast, that probably saved X amount of tissue and contributed to a better outcome. I think the reality is that is not as true. I would be interested in seeing some studies (and I clearly need much more learning) as to when the damage actually occurs in many of these "time sensitive" emergencies.
my point is you say 80 minutes is better than 90, 70 is better than 80. What if the reality is 80 is basically the same as 90, and 70 is basically the same as 80, but 30 minutes is much better than 40.
Honestly, I don't see much of a point in driving code three when you are within 45 minutes non emergent drive of an appropriate facility unless you have one of a very few conditions.
Failed airway with no solution (attempted multiple tubes and your not allowed to place a surgical airway).
Trauma that is hemodynamically unstable.
Unstable STEMI that you think is going to code in the next 5 minutes
and honestly if you are more than 45 minutes to an hour drive from an appropriate facility and you have a STEMI or stroke or unstable traumatic head injury or etc...you should probably be flying those patients on all days with good weather. On days with cruddy weather an hour our I could see running code 3 but if the weather sucks you shouldn't be exceeding the speed limit by much if at all anyways.
Now you can always come up with what ifs and other such things, and yes Code-3 is absolutely critical when dealing with large cities and traffic, just for the mere sake of trying to get people to move a bit.
I would like to understand the time frame of tissue damage in common injuries more. That would help us all make better decisions.