Hi yvonne. I don't know the name of the meds that can be administered, but your oxygen levels, heart rate, blood pressure, etc. will be monitored VERY closely during this procedure, and if anything goes haywire during the procedure, the anesthesiologist or surgeon has drugs to counteract the versed very quickly. You must trust your doctor - please talk to him or an anesthesiologist prior to the procedure to discuss your concerns. DO NOT avoid a procedure just because of the potential risks. Life in general is a risk everyday, and you need to know that you are in God's hands.
Good luck and keep us posted,