This thread is interesting, and to me the thing that makes it most interesting are the continued reports of "I woke up during surgery" despite several posts trying to explain some things from anesthesia providers.
Folks, if you "woke up" from your conscious sedation, if you "woke up" from your spinal or epidural or other regional block, if you "woke up" at the end of surgery as they were putting on the dressings, if you "woke up" hearing the anesthetist say to you "breathe, breathe," if you "woke up" from what you are wrongly assuming to be general anesthesia and actually "spoke" to your anesthetist quickly before "being back out", then you did not "wake up" inappropriately. I just am trying to help you all clear up some misconceptions here so that the people who have truly suffered awareness under anesthesia can have some suitable support and maybe other people can understand their post-traumatic feelings a bit better.
Conscious sedation is a realm of depressed consciousness sufficient to provide comfort while still the patient maintains the ability to respond. Sometimes people won't remember anything when they've had conscious sedation, but sometimes they will. That is ok. It is not expected that you will be unconscious for your procedure, hence the term conscious sedation. You may have heard conversations in the room, you may recall sounds & lights. If you recall something or "awakened" from a procedure you had done with conscious sedation, you did not suffer from awareness under general anesthesia.
Regional blockade, including spinals and epidurals, are not general anesthesia. Spinals are often done for many lower extremity and some abdominal surgeries. Sometimes, a patient who has had one of these forms of anesthesia is provided with some sedation as well during their procedure: Sedation, not general anesthesia (although regional blockade may indeed be combined with general anesthesia but not usually). Again, let me stress, sedation is not general anesthesia. If you awoke from your sedation, you did not suffer from awareness under general anesthesia. You may have heard conversations in the room, you may recall sounds & lights. You did not suffer awareness under anesthesia.
If you awoke and actually "talked" to your anesthesia provider before quickly being "put back out" you were likely receiving some sedation, not general anesthesia. General anesthesia involves the placement of an ETT or an LMA, or much less frequently, a very tight fitting mask. You won't be talking with any of those contraptions in your throat I can guarentee.
If you awakened hearing your anesthetist or anesthesiologist saying "breathe, breathe" you were likely being awakened at the end of the procedure. There comes a time when all general anesthetics must end, obviously, and we do indeed wake you up. And sometimes we wake you up fully with the ETT still in because we may deem it to be the safest (as opposed to extubating deep under anesthesia). Likewise, if you woke up and dressings were being applied, your procedure was over, and you were being awakened on purpose. You did not suffer awareness under general anesthesia.
Also, to answer a couple of other questions which have been posed: First, the BIS monitor is not utilized by every facility. BIS continues to be under study and its use is not standard of care. Mistersister posted that a BIS reading under 30 is unconscious, however, the true number range that correlates with general anesthesia is 40-60. The lower the number, the deeper the state of anesthesia. It is not desirable to run a patient too deep just as it is not desirable to run a patient too light, & I think you should know that some studies utilizing the BIS monitor to gauge depth of anesthesia have shown that anesthesia providers have a tendency to run their patients too deep, rather than too light. Many anesthesia professionals question the usefulness and accuracy of this tool, and so its use is not universal. Also, I must tell you that many anesthesia providers blame the makers of BIS for aggressive ad campaigning that has falsely led to people believing they have experienced awareness under anesthesia or believing that the incidence is astronomical. This thread is largely an example of that, of people who truly believe they had awareness under anesthesia, when they in fact were not receiving a general anesthetic.
Another question: Yes, drugs with amnestic properties are utilized often for general anesthesia. Versed is probably the most common. It is a benzodiazepine with can provide anterograde amnesia. However, not all patients experience amnesia with versed. In addition, versed is not appropriate for all patients. The other drugs utilized during general anesthesia also provide for amnesia and unawareness.
Another misconception that I have read so far on this thread involves pt movement under anesthesia. There are many, many procedures in which no muscle relaxation (paralysis) is necessary. Movement does not necessarily mean that a patient is not adequately anesthetized. The dose of inhalation agent necessary to prevent recall in a patient is about half that necessary to prevent movement to surgical stimulus, and the dose needed to prevent autonomic response (tachycardia, increased BP, etc) is even higher than that necessary to prevent movement. OR nurses who see a patient move under general anesthesia should be aware that it doesn't mean the patient is not unconscious.
Anyway, what this longwinded response amounts to is that people who have really suffered awareness under general anesthesia have endured a traumatic experience, and need support from professionals and others who have suffered similar events. Likewise, anesthesia providers maybe need to be doing more education with the public on what awareness under anesthesia really is, and what the different kinds of anesthesia are. There is obviously, even amongst this group of health care professionals, great misunderstanding of this.