Replacing blood with salt water could retrieve people from the brink of death
bbc.com
bbc.com
Obviously this is not a simple question to answer. If the survival is accompanied by severe disability requiring months/years of rehab, then costs increase, if those surviving are left relatively unaffected then costs would be stable or reduce.
I have a feeling that we are currently in a period of development of medical treatment when we can (at cost with expensive and complex treatment) keep people going for a longer period, both after traumatic injury and in total age. However the quality of life may be low and cost of supporting that life may be high. I think that this type of treatment may be progress towards more simple and therefore less expensive treatments that have less adverse side effects.
Don't get me wrong, I don't believe that replacing a patients blood with salt water whilst also lowering there temperature in a controlled way and performing major surgery all at the same time is "simple", however it does sound a lot less complex than some of the procedures that are done to keep somebody going whilst trying to patch them back together following traumatic injury.