When I was on the BLS truck, the most common to go out to BLS crews were psychs, abdominal pain, and nausea/vomiting. Every now and then they get something different than those three, it turned out to not be nearly as simple as the page said, or they get flagged down.
On my shifts on a P/B truck, it depends. Not all need ALS, but I tech a lot simply because I have already started paperwork on the way. The info we get before arriving on scene is almost nothing, so if it is something that could warrant ALS care I just go ahead and get everything started. I try to get my partners stuff besides basic transfers though, so I will switch up once we get an assessment done.
Additionally, here are some generic scenario questions- would these receive ALS in your system, and what would generally be done?
Psych- Both. Honestly have no idea how they decide what gets ALS vs BLS or what gets urgent vs non-urgent. I think or involuntary psych transfers get ALS. The psych transfers from one hospital are strictly ALS, other hospitals can be BLS. I've never needed to do anything with psychs. Obvious options include physical restraint and chemical sedation.
Isolated, non-life-threatening trauma?- Usually ALS, but I've had it on the BLS level. Get a lot of nursing home fractures, so I usually try to bring some pain control on these. Splinting or position as appropriate depending on the injury.
Falls- Same as above.- Obviously a more severe fall gets ALS from the start, for example a recent ped fall from 10-15 feet.
General medical sick calls (abdominal pain, pain, fever, weakness etc)?- Sick case is really common for both ALS and BLS. Again, no idea how they decide who gets what level and urgent vs non-urgent. Usually they aren't anything too serious, but I have found new onset of things from time to time. They get the fill work up though, sometimes they are surprising. Treat accordingly.
Respiratory/diabetic/cardiac?- I don't think I have ever seen a basic crew get one of these, maybe diabetic. This is pretty much always ALS, the exception being when we have no ALS trucks in service. They get the full assessment and then appropriate treatments depending on the severity of their condition.
Altered mentation?- Possibly has gone out BLS with poor coding, I know crews have gotten strokes etc. These usually all ALS though. Assess, treat.
Arrests/periarrests?- Always ALS.
MVA?: Initially ALS, but I will call a BLS crew for an assist if we have someone who wants transport that isn't needing any ALS care. BLS crews get these a lot though just due to how much we are moving around, I was first on scene for many on the BLS truck just by chance. Usually no treatment needed and frequent AMA's. From time to time some basic pain management and splinting is needed. I've yet to have one in the city that required emergent transport
As far as ALS request, if they request it then it will get sent. It's rare, but it happens. I am more than happy to go out if another crew needs help or have concerns. It depends on the location though, they are good about taking people right away to the hospital if we will be extended. That happens a bit as well.
