I don't think you can buy it yet, but in the same vane of "Where There's No Doctor" or "Where There's No Dentist" this would seem to be a good book to have on hand for... well almost everything.
"The Wilderness Medicine Book"
http://www.gizmag.com/go/7038/

Another option, which is written more for people with only a modest amount of training (it's use as a supporting text for some WFA, WFR courses):
http://www.nols.edu/store/product.php?productid=16455&cat=256&page=1

I find it to have very practical explanations, and understandable treatment options. It goes in more depth than the first aid guide in a typical FAK, but, it's not a medical treatise either. Nice balance for people who are sometimes in wilderness situations, and are perhaps in leadership positions without the benefit of a dedicated medic type person on their team.

I also like that it goes beyond the "hold this person together until the EMS system can get someone here in a few minutes to take them to the hospital". It talks about patient assessment, extended patient care, improvised transport, accident site safety, group leadership dealing with medical situations, evaluating the impact of extended care situations on the rescuer, and other things I forgot. I have the previous edition, it looks like they have an updated one on the NOLS site now.

On SAR here in MA, you MUST be NOLS wilderness first responder (minimum) to be on a search party. For my state to "officially" only recognize one organization says one of two things: they are either highly respected in the field, or highly backed in the government. Fortunately, its the former.

And, the state picks up the bill for cert

I emailed the gizmag and amazon links to a friend of mine who is an Emergency room doctor and a former Navy Seal. I am interested in hearing what he has to say.