I just did mine about two weeks ago so it's pretty fresh in my mind. Keep in mind of course that your instructor may run things slightly differently. You should be briefed beforehand on how it's going to be run--whether you are verbalizing or performing procedures, whether you have a "ghost partner" etc.
Before you do *anything*, "I have my BSI on. Is the scene safe?"
Then, start interrogating your instructor. Time doesn't start until you touch the patient, so ask every question you can possibly think of that might give you a clue. I annoyed the crap out of my instructor, but who cares? You're giving yourself time to think. "How many patients do I have? What's my general impression of the patient? Is there an obvious mechanism of injury? Do I see any weapons, medication, drugs or alcohol on the scene? Are there any witnesses I can talk to?" Anything you can think of, ask.
Then request additional resources--no matter what the scenario, request ALS backup before you touch the patient! If your scenario might require extrication, request fire department backup. If your patient or someone else is combative, request law enforcement. Heck, request them all! You won't be wrong (for test purposes, of course.)
Then establish your ABC's (immediate life threats). Even if the instructor tells you the guy has an arterial bleed that is shooting blood across the room, check ABC's first! Start CPR if you need to. Put them on O2. If breathing is adequate, they get 15LPM via NRB per standing order (can be critical failure if you don't). If breathing is inadequate, start bagging with supplemental oxygen (definite critical failure.)
If it's a trauma, verbalize (or do) manual inline stabilization and put on a collar. Then control bleeding, splint, occlusive dressing--whatever the scenario demands. Do a focused assessment on any obvious injuries, then do a rapid on their whole body. Once you've addressed any life threats, get a full set of vitals, ask how far out ALS is and make your transport decision (wait for ALS, intercept, or transport directly to hospital.)
If it's medical, once you call for ALS backup, address any life threats (ABC's) and put them on oxygen (NRB or PPV), get a full set of vitals, go through your SAMPLE and OPQRST. Ask if there are any witnesses you can get info from. Altered mental status, check their blood glucose and administer insta-glucose if need be. Suspected MI's, don't forget to give aspirin and NTG if indicated (and if the patient has NTG.) Asthma patients, assist with metered dose inhaler if indicated and if patient has it. Check your "five rights" and contact medical direction before you assist with meds, obviously. Know your dosages and how to assist, with each med--very important.
OK, I wrote a lot more than I intended to. Stay calm, remember what you learned. The biggest thing is memorizing those critical failures, which is easy. Everyone gets dinged for a couple of little things, it's no big deal.
Good luck, you'll do fine!
