That's part of my problem with Basic's and IV's. A straight IV does no good whatsoever. The times when giving saline or ringers will really make a difference (and I do mean really) are pretty rare, and more than likely will be seen in a rural, low volume setting where rapid transport to a ER is not an option.
Something like this maybe?
http://www.duluthnewstribune.com/articles/index.cfm?id=50780§ion=None
A neighboring BLS service had this run a week ago or so,