Personally I don't think its a fair question Vene. Especially considering fluid resuscitation/responsiveness is a grey area. Hell when one of the major recommendations by, what many would consider an expert on this very topic (Paul Marik), is essentially give it a try and see what happens.
For something like fluid resuscitation there is no great indicator of your end points, most good studies have shown that almost everything we use to measure it is voodoo (including most of the PE findings we associate with it).
I do consder it a fair question.
One of the only reasons fluid resuscitation is a grey area is because for a long time, in many areas, it has been all or nothing. However, in the ICU environment, fluid balance has been the norm for a long time.
Not just in cases such as hemorrhage, but also in neuro pathologies, as well as renal pathologies. Certainly in MODS as well.
When dscussing overload, I read 5 studies today on its increase of mortality with another handful I need to go over tomorrow. The best centers at fluid balance are using <10% over calculated as the benchmark, with mortality decreasing from 50% to 39% that may not seem like much, but these are patients in which 3 or more organs are failing so that is a big deal.
From the EMS standpoint, and actually resucitation in general, fluid overload is a problem. If you do not think so, consult the studies on fluid resuscitation and cerebral edema (with corresponding mortality and morbidity) in cross-clamp aneurysm repair.
To sum up, overfluid resus kills people.
Now if you are trying to pick a fight on quantitative endpoints, I will agree there are no good ones. But you will be hard pressed to pick any quantitative score or chart that actually does make a major difference with the literature to prove it. Even when they are commonly accepted.
In my opinion these scores are part of the problem. Trying to make medicine so simple anyone can do it simply by starting or stopping treatment at specific numeric parameters just doesn't work. Claiming that it works "sometimes" When those "sometimes" are such low percentages is no better than guessing.
Probably why there are no definitive studies showing the benefits of many of these quantative endpoints and they are constantly being revised, edited, debated, etc.
Moreover, there may never be good studies because of the ethical limits.
I will also nit pick ad say there is a difference between "give some fluid and see what happens" and "2 large bore IVs wide open."
Here is the conclusion, from the review of research by Dr. Marik.
"By virtue of its simplicity, accuracy and availability as a continuous monitoring tool, dynamic monitoring of the pulse pressure, stroke
volume and pulse oximeter plethysmographic waveform would appear to be the ideal methods for the titration of fluid resuscitation in
critically ill patients undergoing mechanical ventilation. Echocardiographic methods of assessing ventricular function and size
complement the information obtained by these dynamic indices of fluid responsiveness. Measurement of EVLW and IAP may be
useful in preventing volume overload. These data should be interpreted in the context of the patients' clinical condition as well as
other parameters including the chest radiograph, PaO2/FiO2, urine output, renal function and cumulative fluid balance. The CVP and
PAOP no longer have a place in modern hemodynamic monitoring."
Bolded type better articulates my point. Maybe I need to start a blog so people will follow my observations too.
When EMS provider claim they are experts, more knowledge and ability is expected.