Expert: Dr Ian Jackson - please note UK based - 10/9/2010

Question
Hi Dr. Jackson.  I recently had a colonoscopy and skipped the sedation part because I had a really bad reaction (nightmares, memory loss etc for quite a long time) to the midazolam from a previous outpatient procedure.  The exam was not terribly painful, but incomplete due to my twisty colon and the doctor suggested that I consider some sedation for my repeat exam.  The doctor mentioned that she uses propofol instead of midazolam (they had a lot of comlaints about it); I explained that I have a severe aversion to sedation due to my past experience and would prefer to be as awake as possible and she thought that this was reasonable.  She referred me to the anesthesiologist and he said that they usually give the propofol in doses to basically put the patient to sleep (then wake up quickly); he really couldn't provide much of an answer as to propofol's usefullness for minimal sedation.  I think that he was irritated that I was asking for something outside the norm.  One of the anesthesia nurses suggested starting with 10mg of propofol and adding small doses 10-20mg  at 5 minute intervals if needed and that this should work for minimal sedation.  So I have 2 conflicting opinions: the first says that the propofol sedation will be "asleep" and the  second says that small doses can be used for minimal sedation.  A third opinion was to use a small dose of fentanyl and to skip the propofol altogether.  I understand that my desire to be awake is unusual (but not unique according to my doctor)... any comments will be appreciated. thanks

Answer
Hi there
There is a lot of published work on the use of propofol for sedation for colonoscopy. Indeed some of it is linked to patient controlled pumps so you get a dose when you feel you need it by pressing a button. This is a bit complex if not used in your unit. The nurse has given the best advice, using small doses as needed of propofol 10-20mg at a time and keeping you comfortable.
Kind regards
Dr Ian Jackson