I tried that this year, I was told it was only for heart and lung problems. But I have heard about people getting it after that, I guess it is up to the hospital.
Never ever the more than 15 years I have been going to Vientiane have I seen they accept that for a tuktuk to the embassy, and even if 400 baht is much, less than 100 would be crazy cheap, it's not that close.