I've seen disputes about how much (can look them up), but as the abstract notes, this was largely a mid-1970s thing, as advanced trauma treatment from the Vietn

I've seen disputes about how much (can look them up), but as the abstract notes, this was largely a mid-1970s thing, as advanced trauma treatment from the Vietnam War filtered into the US, although the process started in the last '50s: https://en.wikipedia.org/wiki/R_Adams_Cowley https://en.wikipedia.org/wiki/R_Adams_Cowley