Expert: Ronald Levy, M.D. - 2/20/2007

Question
My niece had a bone marrow biopsy and was given some kind of anesthesia where she didn't remember anything afterwards. My sister said they heard her screaming though.  My niece was 18 at the time.  The nurses told my sister that that my niece would scream.  Also, I just heard from an acquaintance who had a prostrate seed implant and he said they used the kind of anesthesia on him which blocked his memory of the surgery. I don't understand why they would give people this kind of anesthestic which just blocks their memory afterwards. Evidently, they are awake during the surgery as my niece must have been for the bone marrow biopsy and experince the pain and stress on their bodies and feel the fear, but just don't remember it later.  This doesn't make any sense to me.  Of course, I may not be understanding it right. Could you explain it to me, please.

Answer
Not all cases require general anesthesia...some just require mild or heavy sedation. Examples might be colonoscopy, liver biopsy, bone marrow aspiration, etc. It these cases we generally give 2 or 3 medicines Versed (for anxiety and it is also amnestic), Fentanyl (pain medicine) and Propofol (amnestic and also can be used to put you to sleep). Since sedation is not an exact science, if we give too much, you stop breathing and are effectively under general anesthesia. So occasionally the patient might move or feel pain but they will not remember the experience so there are no psychological consequences. As for the stress on the body, it is actually no different from general anesthesia. You are also subjected to the same stresses, it's just that there are no outward signs of that.

Hope this helps,

Ronald Levy, MD
Associate Professor of Anesthesiology
UTMB-Galveston