(((((skittles))))) it's ok. i had a tube down my throat 1 1/2 years ago. an ultrasound to check on my heart, it's call transesophageal-echocardiogram. my heart was fine. yes, they gave me sedatives. funny thing, my adrenaline resisted the sedatives and they had to give me a lot of sedatives. i didn't get knocked out completely, but it wasn't bad at all. they will spray your throat with a numbing local spray. i didn't feel it go down at all. so, it was no problem at all. it will be ok. don't worry. they'll make sure you will ok, too. they made sure i was ok, since i didn't go completely unconscious. about the resistance to the sedatives, it's really very rare.