IMHO,I'd bring them up.I take the liberty of presuming here that we're talking of a "straightfoward" OW dive here,if such a thing indeed exists,as opposed to being 1000ft into a sump etc.
Step one before you do anything is,STOP and THINK.Get the situation assessed rather than flying in feet first.This is common sense so I won't go over it again but it's easy to over react when stressed.
Basically I'd always bring them up.If the casualty is breathing then bring them up at a normal ascent rate (if you're stuck with that just ascend slowly and ensure you don't overtake your exhaled gas,use it as a rough guide).If the casualty is breathing it's tempting I suppose to make a breif stop,however I reckon our main duty is to get medical attention and as Steph says,you can treat a bend......
If the casualty is not breathing an emergency ascent is the call,what other option is there?
Either way the ascent should be assisted,as Bruce Springsteen said,"It's the price you pay!"Seriously speaking though,if we've planned our dives correctly we know where the nearset chamber is etc.and surface cover will immediately swing into carefully rehearsed action...won't they?
This is obviously breif,for more (better)reading on this please look at the below link,it's written by and for US Public Service(Rescue)divers but the basic info's there.Regards all,take care,Hobby.
<a href="http://www.rescuediver.org/rescue-tech/resc-toc.htm
(Edited" target="_blank">
http://www.rescuediver.org/rescue-tech/resc-toc.htm
(Edited</a> by Hobby at 10:51 am on Nov. 1, 2002)