An additional two cents.... I've been in EMS for longer than I care to think about some days. When I started ALS was limited to a few Critical Care Techs. As a BLS provider (back then) you developed good critical decision making skills as well as the technical skills. I've seen a shift over the years in BLS providers, and that is this: they're taught to call ALS for everything. The vast majority of our calls can be, and possibly should be brought in BLS. The obvious exceptions would include airway management problems that cannot be corrected by an OPA or NPA, cardiac arrest, and medical patients that are truly circling the drain that would benefit from first line medications. The biggest complication on traumas that I've witnessed over the years usually occur with multiple medics on the scene. Trauma is BLS with an occasional ALS trick. IV's and saline locks are not treatments, but rather routes for treatments. If I don't anticipate giving a patient fluid or meds, no venipuncture. Too often Medics initiate this "treatment" because they can. Not because they should. ALS has its place in the field, without a doubt. But so does good BLS. For the record, I'm a NYS CIC, and I've taught the Critical Care program for a number of years, and I've always attempted to instill into my students good clinical judgement, and to do the right thing for their patients. I don't believe there is any cut and dried answer to this issue, it's going to be a case-by-case deal. My best advise is to concentrate on doing quality patient assessments, treat the ABC's and above all, develop confidence in your skills as a provider.