Hmmm, the first thread I click on after the registration turned out to be a tiny gold mine, it's definitely interesting to see all the different opinions... and that's why this isn't really an answer to the OP exclusively, but rather trying to give my response on several points of view surfacing here - what to do first, how long a rapid assessment actually takes, what it involves, specifically, whether to stop at all, etc.
First of all, mrswicknick beat me to one of the points I wanted to make. Regardless of whether or not it's your legal duty to stop and assist a victim, I would always stop. I always treat patients as I want others to treat me or a loved one, and I can't imagine who, when given the option, would prefer to wait for an ambulance and be ignored by a passing EMT. Before someone hits the big red "unprofessional subjectivity" button: no, I'm not talking about involving yourself emotionally and doing CPR with tears in your eyes until you make a dent in the floor - I'm just talking about stopping or moving along. But anyway, everyone makes their own choice in this.
To the OP: I think it's great that you stopped, regardless of how you rate your subsequent actions. If you're in the same situation again, I hope you'll still stop. Medical assistance wasn't developed based on a prerequisite of equipment and pills - actually, it was the other way around. Even the smallest things like a (space) blanket could help sometimes. And even if you have nothing, there's still quite a lot you can do with your own hands and head. Improvise, communicate, control - you can do CPR, control the bleeding, monitor vitals and/or call dispatch and give them further info (I'm always happy to hear a colleague is already on scene and giving me a bit of a heads up on the way).
As far as the rapid assessment is concerned, you can get a general impression in a maximum of 10-15 seconds (this includes evaluating surroundings, other people present, number of victims, possible dangers, patient responsiveness, obvious injuries, etc). OP: It's important to be very aware of all details around you, but everyone's already said that, and maybe that's something specific to focus on. Significant visible bleedings are important here, as well as injuries that are incompatible with life. In your situation, from what I understand, survival would have been quite a miracle, and CPR would have probably brought nothing at all. But it always depends on the situation - assess and make your own call.
As far as the actual rapid/primary assessment goes, I know it can vary according to local protocols. I work in Germany, and what we do is this: check breathing capability and quality, estimate - not determine, just estimate - respiratory rate, as well as the pulse rate and quality in addition to the recapillarization time; briefly examine the thorax, abdominal, pelvic and femoral regions. That's it for starters. Even for one off-duty responder, with experience, it all takes 30 seconds or less and no equipment, unless you encounter special difficulties. So, within 60 seconds (tops) after actually starting the patient evaluation, even with throwing in some "D" stuff like checking the pupils and GCS, you get a good image of what's going on and can make the first choices and take the first actions.
In any case, OP, here's what you absolutely should do: never take my opinions, or any others for that matter, for absolutes. The best you can do is be prepared - train, be aware, get as much information as possible so you can make your own decision and act upon it. I'll say it again, control the situation and make it your call. Even if it turns out to be wrong later (happens to everyone at some point), you know that at that point you acted and did what you thought was best - if you think you could have done better, very good, you've learned from it and you're gonna do better next time.
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h34r: haha
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