For what it's worth, here is something from Snopes.com, which busts "urban legends" - better safe than sorry, even they don't know for certain, this child may indeed be fighting for his life - keep praying, prayers never go unanswered or unheard: http://www.snopes.com/inboxer/prayer/nailgun.asp
There are special people in this world, & they are here to show us a different way to live, often in ways we may not fully understand for a long time. Sometimes they are afflicted with (what we consider to be) very difficult circumstances - which they handle peacefully, much better than we do. Try to see through his eyes. I have a child with autism & other 'special needs' - what the world considers a problem, for me has been a gift & a blessing in many ways, though not without its challenges. I pray for your nephew, & all of you - for Peace, Acceptance, Love, & Hope.