+1 to the above. Securing the scene and stopping the bleeding is absolutely necessary and will facilitate later work immensely. Talk to the victim, reassure the victim,get the history of the accident, any allergies?,do you have a regular doctor? Taking any meds? Act confident, especially if you aren't.

Be prepared to accept failure, even if you do your best. But I was always surprised. If we delivered a victim with a heart beat, the miracle workers on up the line kept it going, almost always with good end results