I have yet to use Med Control in the past year I've worked as a EMT-B, but at least in MA where we use the CMed radio system to contact the hospitals, instead of requesting an entry note, we just request Med Control at that facility, and either an attending or resident would pick up the radio and respond to us. Granted though, Charcoal is our only Med Control option, everything else is standing.
You can certainly use medical control for more in MA. I've used them for refusal clearance, extra doses of Epi (if patient has already taken their own PTOA, to give a third), nitro following an ED drug within 48, etc. If transporting, medical control likely comes from the receiving facility, otherwise special protocols etc come from a facility where we have an affiliation agreement and designated medical director (one hospital per region).
In MA, you certainly can used CMED for medical control consultation, but that process just takes a long time, and not all services have it programmed into their portables (most have it only in the radios in the back of the truck, making it impossibly to use on-scene), so for speed, clarity of discussion and convenience, I use cell phones most often (either department-issued or personal).
One of the services I work for consults a medical control physician before some non-emergent ALS-transfers because it allows us to carry medications and equipment inter- and intra-facility not generally considered ALS-level. In those cases, we call a specific non-emergency medical control number, and sometimes wait a few minutes to speak to a physician.
One of the reasons your book doesn't describe this well is, as others have said, because it differs so much regionally, and even by service or level of care.
Please also be advised, in some systems, if you seek medical control consultation at a facility different than where you transport to, you may need to go to the hospital where the physician is in order to get a signature, after the call.
Hope this helps!
