Well, the idea of an anesthetic isn't to play with your memory is it?

It matters as much as any other pain. You won't (presumably) remember any pain once you're dead, either, yet that doesn't make your worldly suffering not matter. So no, I would definitely not use it.

Of course, it would be less bad overall than same amount of pain which you would actually remember (because in that case the memory would also haunt you afterwards; in your scenario, it wouldn't).

The scary question is, how can we know if this isn't how anesthetics already work? The patient is paralyzed during the surgery, and forms no memories, but is aware during the surgery and simply unable to express their pain, or to recall it afterward?

If the net effect of the anaesthetic is that the (non-)experience makes no impact on post-op me whatsoever, sure. One would assume that being awake during the surgery would be pretty mentally scarring. A drug that alleviates that would be ethical.

I'm under the impression that it has been studied and that pain does show up on EEG and such, and if true, that would seem to place your scenario mainly in the "everything's possible" category (because we would already know if it was so), right?

If the net effect of the anaesthetic is that the (non-)experience makes no impact on post-op me whatsoever, sure. — Kenosha Kid

If the anaesthetic also made you experience time more slowly, at which point would that change your assessment that you'd be fine with it? If the surgery takes an hour and you're in terrible pain for what feels like an hour, you're fine with it. But what if your agony would feel like it lasts two hours, a week, a year? Would you still be fine with it as long as you remember none of it afterwards? If so, why does the duration matter?

If the anaesthetic also made you experience time more slowly, at which point would that change your assessment that you'd be fine with it? If the surgery takes an hour and you're in terrible pain for what feels like an hour, you're fine with it. But what if your agony would feel like it lasts two hours, a week, a year? Would you still be fine with it as long as you remember none of it afterwards? If so, why does the duration matter? — zookeeper

I agree, it does not. Or, at least, that's my majority opinion. From a rational standpoint, since I will not suffer any consequences (except for the benefits of surgery) after the event, and I will make the decision before the event, I can safely agree to it and live with it afterwards.

The scenario you're describing is quite horrific, and, if I were aware that this would definitely happen to me, that horror would likely effect my decision. But that would not be a rational objection, just an emotional reaction to the magnitude of the horrific idea. I might have such a reaction to e.g. gory details of the procedure in advance.

That said, rational me comes back with: "If someone told me this would happen, I would call BS on it." Anything of that magnitude should leave some effect on the sufferer, which would violate the final-state condition I gave in my previous reply. So even if I were wrong and it were true, I would discover this after I disbelieved it and made my decision, and would never know or regret or tell of it after. Should I find out by some other means later, I would keep the stance that it was ethical, presuming the surgery is necessary.

Midazolam serves this purpose and is commonly used in conjunction with anaesthesia.

The shock would kill you before you had a chance to forget the pain, this is shown by early attempts of surgery and early experiments with anesthesia.
In order to survive the pain you have to move away from the conscious realm that the pain occurs as it were hence opiates and synthetic compounds

wow i had no idea. Fascinating

If the anaesthetic also made you experience time more slowly, — zookeeper

Wouldnt this mean the intensity of the pain would be extremely reduced... as your perception of the frequency (time dependent) of pain impulses that you're receiving from the injury site would be dilated out along a longer time period. I guess I would come across as a dull continuous pain