Greetings--
My husband's interest in leaving his body is limited, but last night he had the clear dream of himself asking ,"Why, in the many times I've had anaesthesia, have I never used that time for leaving my body?" He has never nearly died, so I assume he meant leaving just for exploring.
In his dream nobody answered, so I offered to bring his question to you all. Any help appreciated.
bets

I would think that being under anesthesia only makes it easier to go out of body but it doesn't make it automatic.  I think you have to consciously decide to go out of body in this instance, or if you are a person who thinks about this topic a lot then it would be easy for you.  I would think anesthesia might also make it hard to remember.

When I was 17 I had dental surgery.  The anesthesia was supposed to make me sleep through the whole thing.  It did, physically.  But mentally I was awake the whole time, could see and hear everything that was going on.  I didn't know at the time that this is a first stage of leaving the body, otherwise I would have chosen to go somewhere else!  But instead I thought I was physically awake so I just stayed put like a good patient.  It was very boring, let me tell ya.  No one believed me though.  The dentist insisted I was asleep, but was amazed that I could tell him all that happened and was said, etc.

Bets,
I had heart surgery a year and a half ago and was under anesthesia for a very long time.  I don't have much memory of anything during that time.  The only thing I remember is seeing the face of a very strange looking man.  The color of his skin was a luminous blue/green (those are the only words that come close to the right description).  I told this story to another heart surgery patient later and he got all excited and said, "yeah, the death masks!  I saw them too!".  Actually, I don't know what he was talking about but he did have a memory of seeing something while under the influence of anesthesia.  In case you don't know, during heart bypass surgery they stop your heart for appoximately 60 minutes while they attach the bypasses and they keep you alive via the respirator. 

I've been OOB before the surgery and OOB after the surgery but not during (at least I don't remember if I was).

I hope this is useful.

Love,
Rick