I’ve had more experience with medical sedation in recent years than I’d hoped to, what with issues both “north and south” if you get my drift.
So they knock you put with Milk of Amnesia, er propofol, do what they need to do, and you come to in the recovery area. feeling pretty decent and almost coherent. Maybe not perky, but definitely capable of holding a conversation and walking around.
Then 2 hours later your brain says to you “about that being awake thing? Yeah, I was just joking” - and you’re out for another 3 hours.
So basically: why does it seem to wear off, then knock you out again later?
IANAD but my understanding is that undergoing surgery is actually a very physically intensive procedure considering you’re just lying there while you’re doing it. But it’s really the equivalent of a hard work-out and you’re going to be exhausted afterwards.
So the anesthesia wears off and they wake you up to make sure you’re okay. And once they’ve checked that, they let you rest. At that point, the exhaustion from the surgery kicks in and you fall asleep.
Presumably if they gave you anesthesia and just let you lie there for a couple of hours without performing any surgery, they could then wake you up from the anesthesia and you’d remain awake.
That was my experience as a medical research subject last month. The doctors put me under with propofol, then with Sevoflurane, for six total hours of unconsciousness. A little grogginess and nausea upon awaking, but back to normal within an hour.
Unconsciousness from anesthesia is also not the same as sleep. Sleep is restorative, anesthesia is not. If you were short on sleep from the night before, or had a procedure the body needs to heal from, your brain and body will still want to sleep even if knocked out from Milk of Amnesia (I’m stealing that!) not long before.
I have had six surgeries. I must disagree that I ever felt “coherent and pretty decent”. I was well and truly exhausted. It was more akin waking up in the middle of the night for few minutes and then needing to sleep.
This. The drug renders you unconscious. Then you experience physical trauma as your anatomy is forcibly rearranged. Then you return to consciousness. All that is quite tiring.
But if it’s something relatively minor (in my case, an endoscopy or a colonoscopy)? OK, after dental work I can understand it; I’ll take something (and/or use nitrous) to deal with the sheer terror and stress and maybe that’s still taking its toll…
Relatively minor still means your central nervous system is tampered with enough to make you unconscious and makes your muscles relax enough to have a 10 foot tube introduced down your mouth/up your butt. These events are stressors, and your body will react to them. Be glad a nice nap clears up the worst of it.
