MAC doesn't indicate the depth of the anesthesia. It indicates the depth of the paralysis. Which is exactly the problem EEG monitoring is supposed to prevent: In some cases patients can have an insufficient response to analgesia (so they will feel pain) and hypnotics (so they are awake, aware and forming memories) but will respond to paralytics (so they are unable to move and communicate their predicament).
So with this kind of practice, you create any patient's worst nightmare: being cut open, feeling everything, knowing everything, but unable to stop it. And you are unknowing, uncaring or too cheap to prevent that e.g. via EEG monitoring.
Edit: Parent removed his comment. Roughly, from memory, there was some claim by him about being a professional anesthetist, having very rarely encountered EEG and only bi-spectral index monitoring (an EEG-derived computed measurement) in some IV cases, some claims about the unreliability of both and about the preference for MAC (minimum alveolar concentration) to monitor depth of anesthesia.
Anesthesia gasses aren't paralytics. MAC is not about chemically preventing muscles from activating but depressing consciousness to the point that muscles don't move in reaction to painful stimulus. Chemically blocking muscle movement (neuromuscular blockade) takes an actual paralytic like succinylcholine. Pain control is yet another, separate factor. Even with depressed consciousness from a gas/propofol infusion and neuromuscular blockade, blood pressure (which is part of standard monitoring!) still will spike in response to painful stimuli. So usually, anesthesiologists will give an opioid in addition to gas/propofol to control pain, even if the patient isn't conscious and wouldn't be consciously aware of the pain of surgery.
The nightmare scenario you describe is when a patient has neuromuscular blockade, is not being given sufficient gas/propofol to depress consciousness, and has inadequate pain control that isn't being picked up in the blood pressure either because the anesthesia provider isn't paying attention or is controlling blood pressure through drugs to the point they can't see anything. If, for some reason, that kind of anesthetic is medically necessary, benzodiazepines can (if tolerated) prevent memories from forming lessening the chances of psychological trauma.
MAC is the alveolar concentration (so strictly speaking defined only for anesthetic gases) at which half of people show no motor reaction on surgical incision. I understand your interpretation about paralysis, but we know the measurement endpoint is not paralysis in practice. Gases are hypnotics, and although they do cause some amount of muscle relaxation they do not induce paralysis. Hence the need for other drugs when we need paralysis. BTW, there is evidence that EEG prevents awareness under anesthesia, but it's not a guarantee either. Fortunately, awareness is extremely rare even in the select cases where it occurs more often (emergency C-section and cardiac surgery, especially in seniors).
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>Single-trial classification of awareness state during anesthesia by measuring critical dynamics of global brain activity (2019)
> The minimum alveolar concentration (MAC) is the minimum concentration of an inhaled anesthetic at 1 atm of pressure that prevents skeletal muscle movement in response to a surgical incision in 50% of patients.
So first, you do not measure the depth of anesthesia, you measure the concentration of the anesthetic. Second, you judge this concentration by the prevention of muscle movement. Called paralysis.
Edit: In case you are wondering why this response doesn't really fit the parent comment, the parent saw fit to completely replace his comment without an indication that he did so. Originally there was a claim in the parent comment about "MAC being the primary indication of anesthetic depth being the textbook definition" or something to that effect. To which I responded. I guess I must have hit a nerve there ;)
"MAC being the primary indication of anesthetic depth being the textbook definition"
I am an attending anesthesiologist and this is true. MAC cannot be interpreted at face value, though. You've got other drugs on board (not accounted for in MAC), the patient might be frail or very old, etc. etc. All things changing MAC interpretation, which is why there are still anesthesia providers instead of robots ;-) We currently have no way of faithfully measuring the depth of anesthesia, and our understanding of consciousness/awareness is incomplete. Anesthesiologists have to rely mostly on know-how, even in 2025.
It obviously varies on place of practice and the way you were taught. My understanding is the evidence is pretty clear that it helps but happy to defer to your lived experience.
This is it, combined with the points brought forth by the parent. Like all things, a healthy balance seems to be the optimal strategy. Life’s a journey; good idea to plan but the people and places you find off the beaten path are often the most rich and rewarding.
“…doctor roles (e.g. anesthesia)…” Anesthesia has primarily been a nursing role, and it’s been this way since the American civil war. Physicians didn’t really want any part of it early on as it wasn’t very prestigious or lucrative. Nurse anesthetists have historically provided and continue to provide the vast majority of anesthetics, in the US at least.
Funny, I was addicted to nicotine for around 10 years. I got tired of smelling like smoke and I became really tired of the taste. Decided to quit one day and just stopped and have no desire to go back. It was incredibly easy. That was around 20 years ago. Caffeine/Tea/Coffee I am fiendishly and hopelessly addicted to; having tried numerous times to quit or cut back intake and I always fail.
My experience is similar. I started drinking coffee when I was around 15 and only took two very brief breaks like <2-3 weeks through my 30's. The acute withdrawal was hell. A few years back I decided to quit caffeine for one year and get fully past the acute withdrawal. The withdrawal was hell and so was the long withdrawal. I never felt normal for a full year. I slept great but felt mentally and physically sluggish, esp. mentally, for the whole year. The drug docs call this long withdrawal PAWS for "post-acute withdrawal syndrome". Most doctors are oblivious that it applies to caffeine too. I made it a full year and resumed drinking coffee and my mind and energy improved immediately. I only drink about 2 cups in the AM now but I am very slowly weening myself off by by gradually reducing the number of scoops of coffee in my brew to protect my sleep.
I smoked for about 2 years in grad school but had no problem quiting. One day I just stopped and like you I had no desire after the initial urge was gone. Maybe I was not fully addicted yet.
I have the exact same experience when I quit coffee for any lengthy period of time. Short term withdrawal is hell, then boost of energy and the best sleep of my life consistently every night. Feel great for several weeks then realize how mundane and boring everything is without the buzz, have a cup of coffee and WOW, Im alive again! It's a brutal cycle and I fear I've done irreparable damage to my brain at this point.
As an aside, I highly recommend the Audible book "Caffeine" by Michael Pollan if you haven't already heard it. It's quite brilliant.
That is basically where I am at with my relationship to caffeine/coffee. Sleep much better without it. But life feels a little duller without it as well. And then my first cup back after a long period of abstinence is absolutely magical. That feeling quickly fades after about a week of use though.
I tried limiting it to just once a week to see if I could capture the magic, but my discipline was lacking a bit, and even when I was able to stay on that schedule, it still felt like my tolerance was building.
"Friendships are formed through shared experiences. The more intense and positive the experience and its outcome, the more durable the friendship. Simple as that."
Propaganda and hyperbole aside, it must be clear to even the most obtuse among us that the earth is a finite system sphere with finite system resources. Even if it isn't as bad as we're being led to believe, the steps we could be taking to mitigate a positive feedback spiraling collapse in the system loop are things we should be doing anyway. I don't see how anyone here can argue that generating millions of one-time-use plastic receptacles is a good idea in any system or in any way sustainable long term, so what is the harm in making the changes we should be making now, as if it were as bad as we're being led to believe?
Why do people conflate climate change with plastic? Does creating reusable glass or metal containers use less energy or create less CO2 than making things from plastic?
Plastic pollution (particularly in the oceans) is really disturbing, but other than burning it, I don't see what it has to do with warming.
Before we were concerned with the climate, we were with the environment. The amount of plastic pollution, especially the potential impact of microplastics, is part of that, like global warming. At least in my view, I see them all as negative impact on our environment. At minimum, negative for ourselves.
Mercury, pesticides, and plastics in the ocean are horrible in my opinion. However, I've seen more than one person who seems to think recycling is going to have an effect on atmospheric CO2 levels.
I’m not sure where the idea came from, but Michael Pollan has also propagated in his books this idea that human beings have been domesticated by plants. See, The Botany of Desire.
