I look at it as the prep time for IV versus IO is about the same. Looking at the initiation of the puncture, IO faster. Secondary fluid or med administration seems better with the successful IV. IO's have the need for pressure infusors that take a little time, etc.
My feeling is alternative fad that is useful in particular patient populations where IV access may be delayed or impossible. If so, go IO. Routine IO because someone is lazy and hazy to gain access via IV should be looked at closely.
Everyone has valid responses, etc., but being opinionated, you should be able to get the IV. If not, the skills seem to be lacking.
Overall, my first impression is that the 75% is greatly inflated, however, one must look at the evidence closely, The question is as addressed, why all of a sudden the great influx of IO's?
Around here, rare IO's unless no IV can be started. EJ's usually prior to IO.
Waiting for the true numbers.
Great question/post!!