You should probably abstain for a few days beforehand, but I have never heard of this being a major problem even for a heavy cannabis smoker.

Do quit the cigarettes, though, as they're horrible for you, in or out of surgery, if you are able to. Or at least cut back. The better shape your lungs can be in, the better.

As for the cannabis though, just quit a few days beforehand, it shouldn't be a problem.

I am the one that originally posted the bit about cannabis making novocaine/lidocaine/etc less effective. It's not dangerous; it's just that it can make the topical anesthetics less effective.

FYI; hope that clarifies.

I'm not an anesthesiologist, but I do have a medical background, and I have NEVER heard that cannabis is dangerous when combined with anesthetics. I think somebody fed you some misinformation on that one.

You can OD on anesthetic but a good anesthesiologist will do EVERYTHING medically possible to make sure you have a safe surgery.