Bedside brain debridement

The story goes on this unfortunate gentleman is that he got up in the middle of the night and shot 4 of his ANP buddies. Then he jumped into his truck and hit a barricade and thus suffered bad head trauma (yes, there is exposed brain matter). One died, and 3 were critical. Now the 3 are doing well, but this guy is essentially dead, expect that we are keeping him alive on the ventilator and his heart works fine. The next day, rumor has it that these 4 tried to force themselves upon him and he retaliated by shooting them. Not sure which story to believe. The only reason I am not advocating to take this guy off the vent is that he has a lot of electrolyte and acid-base abnormalities which I am using as teaching points. His sodium is 179 and potassium is 2 (we caused this by giving him a bunch of mannitol for the past two days without checking labs). Our lab machine broke the day after he came in, the day we started the mannitol (draws a lot of water out of the cell and eventually you pee it out). I was surprised we started the mannitol because they asked me how much mannitol they should give him and I told them it was not a good idea. On this day, the decided to do a bedside debridement of his skull.