Yeah basically the best you can hope for is a bandage and a medevac and maybe he'll survive. Literally not a damn thing in the field you can do though.

But listen to the agonal breathing at the end. Dude's brain is completely scrambled. Enough of it still barely works, he's lifting his head, pathetically reacting on some lizard instinct, but eventually all the blood and mush inside begins squeezing it and his whole system collapses. His brainstem was the only thing trying to keep it all together.

I'm surprised he just had what looked like a graze and it didn't bust his dome open.