In the medical world, the word "STAT" means that urgent/immediate. It's derived from the Latin word "statim."
So, when a doctor needs an immediate consultation, that's considered a "STAT consult." Could a physician use Twitter to obtain such a STAT consult? I think they could, especially if they're connected with the right physicians on Twitter. I'd love to see some physicians publish case reports where they effectively used Twitter for a STAT consult when they were dealing with an emergency. I suppose the biggest challenge is to explain the situation with only 140 characters. However, you could send out a tweet like, "STAT consult: should I give TPA for this stroke patient?" and then you could get a conversation going. Of course, once you get the conversation going, you should pick up the phone. So, maybe Twitter could be used to get you in touch with the right consultant when you're in need of a STAT consult.