Asking if you've ever had one? I had one when I was working IFT. Granted, receiving facility was as close as paramedics thus paramedics weren't indicated under the circumstances. However I did feel like an ignorant schmuck when my "CVA" patient had complete symptom relief with a dose of D50.
So, how do you rule out hypoglycemia in a patient with a history of diabietes and taking hypoglycemic agents, including but not limited to insulin (this is, of course, ignoring the differential of insulinomas)? Patients lie, patients misremember, patients accidentally take two doses of their medications. More importantly, how many EMTs know which medications can induce hypoglycemia and which can't? It certainly isn't in the education beyond "Diabetic, think hypoglycemia if altered."
Is it not presumptuous to, absent of data leading elsewhere, exclude a valid emergency level differential? If you have a patient presenting with unilateral neurological signs, would you just call a code stroke and not get a BGL?
If the patient is entirely unconscious, thus presumably no or very limited HPI, then how are you going to narrow a differential down to hypoglycemia vs CVA anyways, instead of adding the other bajillion differentials that can lead to an unconscious state?