creatine and muscle atrophy from brain damage?

I'm a cna and taking care of a 5 year old drowning victim who had severe brain damage and was completely dead for 30min. He had gone through tremendous rehabilitation and is slowly recovering and he also has muscle atrophy. I know he can do a lot more as for recovering but I was wondering if a small dose of creatine would be effective at helping him achive muscle mass so I can continue teaching him to walk? Of course I would consult the parents first but it was just a question I had? I am also a rehab assistant as well but I only know so much.