It's even more challenging for echocardiology (or ultrasound of the heart). And this is a graph of response from ED directors about the availability of the echo. This is not even by time of day and only 10% said that echo was easily available.
So why aren't most people doing POC ultrasound? Probably the biggest reason is that it is a user dependent technology and requires education and training to use well. There are turf battles - resistance from other specialists who don’t believe other physicians should have access to this technology. There are concerns about it being time consuming or just difficult to do. It’s really going to vary by medical setting.