I think the closest a doctor could ethically do at this time to what you are suggesting is one of the different kinds of gastric bypass surgery, and even those, someone has to qualify for by being healthy enough (other than their weight) to take the stress.
The problem with knocking someone out and keeping them on an IV is that being kept knocked out has its own health challenges. They only do a "medically induced coma" in cases where the patient would die if not kept in that state: it's somewhat dangerous in itself and a patient being kept "out" requires constant attention and care.
If someone was just on an IV and being monitored, I think they would get desperate pretty fast because they would feel so starved. It's possible too that the IV wouldn't be enough to maintain hydration, electrolyte balance and the bare basics of nutrition -- there are risks to the internal organs if someone goes into a starvation state.
There was a fad in the 1960s for doing 10-day fasts. (People just did this at home.) The fad didn't last for obvious reasons.
Probably somewhere at a weight-loss spa, some doctor has considered doing the kind of thing you are suggesting. Haven't heard that it has caught on, though. People do complain that when they go to a weight-loss spa, they feel starved, and that's with the food they do give you. I think, though, that the main reason this approach wouldn't be something a spa would try to put in their lineup is that people who lose a lot of weight in a short time almost always come back to their original weight within a year or so. Fast, extreme weight loss often has that outcome.
Because obesity is such a problem, the research is going hard and fast to come up with answers. I think recently they announced research into a drug that showed promise, coming at weight gain as being the result of a genetic lack and in some way making a correction. That might be the real future of medically assisted weight loss.
I'm really glad for you that you feel noticeably better, and your medical emergency had the silver lining of losing some weight you don't mind losing. I hope you're able to keep it off, it's definitely a constant challenge.
Wegovy is a new drug that's been approved by FDA for weight loss. It's a once/week injection and is said to work very well. There's also Ozempic that's, currently, being used to treat Diabetes, but is in the process of being approved for weight loss.
The biggest issue with these drugs at this point is the cost. Insurance often doesn't cover them and the typical cost is around $1000-$1500/month, which is prohibitive for most of us.
I agree with Annie that rapid weight loss, such as you experienced is not healthy and is almost always gained back, often with more added. Now that you've lost it, the best way to try to keep it off is adjusting your diet and getting plenty of exercise.