You know that thing in movies where someone’s on an operating table, a mask comes down, everything gets blurry, and the next thing you know, the patient is crying and blabbing something really embarrassing about their childhood to the post-op recovery nurse? Well, that’s kind of true. What’s actually going on in your brain and body when you go under is way stranger and a lot more carefully choreographed than Hollywood ever shows. Anesthesia isn’t quite sleep and it’s not quite death — it’s more like time travel, but you can only jump forward. Anesthesia is basically a reversible off switch for certain parts of your nervous system. What you’re probably used to is someone saying, “Okay, just take some nice deep breaths and count backwards from 10,” in the same way you would tell your dog you’re taking him to the park when you’re really taking him to the vet. You might get medications through an IV that work in seconds, or you might breathe in anesthetic gases through a mask, which takes a couple of minutes to work. For most people, the last thing they remember is counting backwards. What’s happening in your body is a cascade of events. There’s sedation, where your awareness starts to fade. Then there’s loss of memory, where your hippocampus stops storing new events, followed by a loss of consciousness, where your brain’s communication networks basically go offline for real world input. Next there’s immobility and pain control, where your spinal cord and pain pathways are suppressed so you don’t feel pain or jump off the table. All this happens in about a minute. The weirdest part is that you don’t feel yourself losing consciousness because there’s no consciousness there to feel anything. One second you’re in the operating room and the next you’re waking up in recovery wondering what happened. The bottom line is that you’re not in a deep sleep, you’re in a pharmacological blackout. Drugs are making sure your brain can’t record what’s happening, so even if your brain does receive a few stray signals, there’s no footage to play back later. Here’s another surprise — waking up from anesthesia isn’t like waking up from a nap. Once the drugs start wearing off, your brain’s networks begin reconnecting and coming back online, but not all at once. That’s why you feel groggy or confused. Your sense of time is scrambled, as it feels like you were just wheeled into the operating room a few minutes ago. Nurses could write books about what people blurt out after surgery, which is why it pays to be nice to them in pre-op.
