At this point, I don't see much advantage in field POCUS, at least for doing things like determining destination or the like. I do, however, see that doing USGPIV in the field with an appropriate probe could have some benefit for your patients that present a PIV challenge... if they're willing to be reasonably still during the procedure. I'm extremely good at doing PIV without US and have been known to be able to obtain PIV access in some patients where USGPIV attempts (by others) have failed. I've recently (within the past year) have started doing USGPIV and have become reasonably proficient at it. If things go smoothly, it only adds a couple minutes to the PIV process, though if things get more challenging, it can easily take 20 minutes or more to obtain PIV access.
In my ED we also have the availability of a vein finder and I've done a few starts with that, and it is an interesting piece... though I use it more as a screening tool as to where to concentrate my efforts. One irritating thing is that shallow flat veins look basically the same as shallow plump ones... Occasionally on more "fluffy" patients, I have been known to use US to take a look at something that I think is a vein.
On the flip side of things, POCUS, with appropriately trained practitioners, could have some field benefit under some circumstances. Of course if you're getting educated and trained well enough to be able to use POCUS for various screenings, you probably should also have a commensurate increase in procedures authorized (with appropriate training) to deal with what you find. Of course by then, you probably would be able to easily live-stream what you see to medical control even from relatively remote locations and get guidance as to what to do.
