I suggest to you, my fellow medical provider -- be you in the EMS realm or the ER -- that the above question is possibly the least useful question in any urgent/emergent medical situation.
First, let's accept the maxim that we should always assume the worst possible cause for a given set of symptoms is the actual cause until proven otherwise. "Assume the worst" was how I was taught in -P school: "Yes, the patient could be having a mild cause of heartburn, but treat as if it were an MI until you are absolutely certain that it isn't."
If that's the case, then take any set of symptoms that could be the result of being drunk, and tell me which one ISN'T a potential symptom of some greater pathology:
Ataxia? Yeah, probably just drunk. Or maybe a Transient Ischemic Attack.
Flushed skin? Probably the third 24oz tall boy. Or an early sign of allergic reaction due to histamine release.
Decreased mental status? Booze? Or Hypoglycemia? Or decreased cerebral perfusion?
Slurred speech? The bottle talking. Or is it a stroke?
Point is that most every single clinical symptom of alcohol intoxication is also a symptom of some greater, more serious condition.
Now, combine that knowledge above with the seemingly widespread attitude of emergency medical providers that causes us to think "Well, if you weren't drunk, you wouldn't have these symptoms", which causes us to then STOP looking for other things, and you've got a problem.
Couple years ago, back in the ATL, one of my fellow medics brought a patient in, "Just drunk, needs to sleep it off." This diagnosis was made by the presence of an empty bottle of whiskey and a nasty case of halitosis (Old Crow, as I recall... nasty stuff). No vital signs, no physical assessment, no actual physical contact with the patient other than to pick him up off the ground and put him on the stretcher.
At the ER, the triage nurse, being prudent and wise and really smart, decided that perhaps a set of vital signs would be in order. You know, Blood Pressure, Heart Rate, Respiratory Rate, like that.
The Heart Rate? 204 beats/minute. BP? About 70/systolic.
The good news is that the patient was promptly wheeled back to a room, where an IV line and a dose of Adenosine converted that SVT into something more conducive to a decent degree of perfusion.
But if it hadn't been for the assumption that the patient was "just drunk", he might have been treated sooner. And I see the same problem when people have been drinking... the medic or nurse or physician is easily lulled into assuming that the symptoms are all because of the booze.
So, given that the answer to that question often leads us down the wrong treatment path, and that it offers no relevant information that would guide treatment, is there a reason we bother to ask it?
Discuss, if you want.