As a dream upon waking... except not.

October 2, 2012 5:40 PM

I've had twilight anesthesia for minor surgical procedures three times. The first two times everything went fine -- I have no memories of the procedure, woke up happily and felt back to normal within an hour. The third time I "woke up" in the middle of the surgery, still have fairly vivid memories of feeling pain and being operated on, and it took me eight extremely unfun hours to completely recover. What happened that third time?

In addition to becoming aware/forming memories during the procedure, I felt absolutely awful for eight hours -- I can only compare the feeling to being as tired as I've ever been but unable to sleep. Being asked a simple yes or no question (e.g. "do you want a glass of water?") felt like such an unbearable imposition that my answer was invariably "Leave me alone!!!"

All three times anesthesia was administered via IV -- I believe a combination of propofol and demerol, possibly midazolam as well. During the first two surgeries an anesthesiologist administered the IV, but the third time a nurse was in charge (I totally understand that nurses are qualified to administer twilight anesthesia and I'm not suggesting that's why I had a bad reaction, just providing a datapoint).

So what happened? Is it a common occurrence? Has it happened to you? Are some drugs used for twilight more likely to cause this kind of problem than others?

I know, I know, ask the doctor who performed the procedure. The doctor is very busy and hard to reach, and besides, I'm just curious. I have a medical condition that means that I'll be having procedures under twilight anesthesia pretty regularly for the rest of my life, so if this is indicative of a common sensitivity or anything like that, I'd like to be prepared to bring it up.

posted by telegraph to health & fitness (8 answers total)

Anesthesia specialist here. Amazingly, the exact ways anesthetic drugs act on your brain is not completely known, nor are the mechanisms for what you experienced (Intraoperative Awareness, and/or Post Operative Recall).

Chances are, you were simply given less drug the 3rd time. During "twilight" procedures, sometimes anesthesiologists choose a low dose, and they probably chose it too low for you. This is more likely with a nurse than a very experienced anesthesiologist, but it can happen with either.

Nothing really to do about it, except tell your next anesthesiologist that you had some awareness and recall the previous time, but not the two times before that, and that you should probably be given a dose on the high side.

As for feeling like crap, I can give you a guess, but this is not in the medical literature and is based on what is being discovered about anesthesia in the past 2-3 years. At high doses, anesthetics silence your brain. Given enough drug, your brain can get to zero or low electrical activity ("isoelectric") or intermittent activity with long periods of silence ("burst suppression"). At low doses, however, anesthetics do not silence the brain or even quiet it. They can actually cause a shit ton of aberrant, widespread electrical activity, which may or may not cause more side effects (post operative nausea and vomiting, post operative cognitive dysfunction) than a knock-you-out dose.
posted by kellybird at 5:54 PM on October 2, 2012 [37 favorites]

Neither a doctor nor any sort of anesthesia specialist. One thing to add to what kellybird says--sometimes when this happens they will give the patient an extra hit of Versed (which blocks memory) in hopes that s/he will not remember a glitch. Perhaps they did not notice a/o give extra Versed the third time. Just a thought. I am sorry you had to go through that!
posted by skbw at 6:42 PM on October 2, 2012

Kelleybird, thank you for that, because I've only had two twilights; one was efforftless with instant recovery, and the other was horrible with epic nausea and long recovery time. Now I have a compelling reason to get records of the dose level used to help inform the decision on amount if I need to go under again.
posted by davejay at 6:44 PM on October 2, 2012

Oh and regarding your other questions --

How often does it happen?
1 in 500 cases

Does this indicate a sensitivity?
I'll give you some info on a) what is known, and b) what you can do about it.

Some people do indeed have genetic predisposition to ultrafast metabolism of anesthetics, for instance many copies of P450 liver enzymes, or other related enzymes. If you tend to have drug troubles in general, it might be related to your genetic makeup and something you call a sensitivity. Or you might just have not gotten enough! There is not currently a test of this that's in widespread use. There is experimental genetic research that you'll be seeing more of in the clinic in 5-10 years. Even still, the relationship between genetic makeup and specific anesthetic (or any drug) metabolism is not well worked out.

So what you can do about it? Typically this is a guess and check approach. If you did not fare well with your last drug combo, and you will have lots of surgeries, it's worthwhile to get a copy of the operative record so you can let your next anesthesiologist know the dose you got. That doctor might: up the dose, try anesthetics from a different class (e.g., dexmetatomidine, nitrous), or give you inhaled anesthetics that bypass the need for metabolism in the liver.

If you will indeed be getting lots of surgeries, and you already had one instance of post operative recall, it's worth consulting with an experienced anesthesiologist prior to your next surgery. You should consult with an MD anesthesiologist and not just your surgeon, because surgeons have a different knowledge base. Nurse anesthetists also usually have a less experience than anesthesiologists especially in non-standard drugs... just based on # of years of training and less exposure to difficult cases in routine practice.

Or... what you just wrote davejay. Good luck!
posted by kellybird at 6:46 PM on October 2, 2012 [3 favorites]

One note: be sure that they have your correct weight on file. When I had my wisdom teeth out, I woke up in the middle of the surgery (from twilight sedation) and remember the Bob Marley songs they were playing (and also the nurses telling me to close my eyes and go back to sleep). Turns out that they didn't believe the weight I told them and low-balled the dose. Not sure why they would have thought I would say I weigh more than I do, but apparently it happens.
posted by charmcityblues at 8:34 PM on October 2, 2012

sometimes anesthesiologists choose a low dose, and they probably chose it too low for you. This is more likely with a nurse than a very experienced anesthesiologist

This doesn't make sense. Nurses don't prescribe drugs, so they wouldn't be choosing a dose of any level, high or low. Do you mean a CRNA?

Telegraph, it would be worth examining the drug combos and doses you received for these three procedures and making a comparison. When you call your surgeon to request that information, you can also discuss what happened to you during the third procedure. I would also make sure your anesthesiologist/CRNA at your next procedure knows that this has occurred.
posted by pecanpies at 9:08 PM on October 2, 2012

Do you mean a CRNA?

Yup, the poster said s/he had a nurse anesthetist. About 1/3 practice without supervising anesthesiologists.
posted by kellybird at 9:16 PM on October 2, 2012 [1 favorite]

I have woken up during twilight and general.

When I had my wisdom teeth taken out I woke up in the middle with my mouth stretched wide open and feeling like someone was jackhammering my skull. I remember them saying "he's awake, push more something something," and then they denied I had woken up later. It could have been lack of experience, because the nurse who put the IV in needed the dentist to take over because she couldn't work the thing that sprayed cold numbing agent on my arm or the IV itself, it seemed.

Then when I had a femur fracture and they reamed out my marrow and implanted a titanium rod, I remember being awake for a large part of the time when they were getting everything aligned with a fluoroscope, and I remember watching the fluoroscope. I have no idea if that was normal, because afterwards they were surprised I knew they used a fluoroscope but were sure I had not woken up.

Perhaps I only was awake enough to hear everything? I don't know.

I think I have a very fast metabolism and things usually hit me hard but don't last long. So maybe they just weren't expecting me to come out so fast?

I will certainly tell future doctors of these experiences.
posted by MonsieurBon at 8:08 AM on October 3, 2012