It's done differently for different folks, ask your doc, it seems like you two need to have a chat concerning the procedure, anyhow. Even if you have talked to him already, sometimes we don't catch everything we want to know in one sitting. (I know I don't!). I am sending you a website you can look at, has some good basic info. Your husband may be awake, or slightly drowsied (most likely) and they will numb his throat for him, sometimes they do it in the x-ray department under flouroscopy (Where the doctors can see everything as it moves through, like a x-ray motion picture).

http://www.gicare.com/pated/epdgs25.htm

Hope this helps some,
Andrea