Many people have heard stories of people who awoke during an operation performed under general anesthesia. Some of these are horrific tales of people who awaken during surgery to find themselves unable to move or speak, yet fully conscious, and fully able to feel the dreadful pain of the operation they are undergoing. The video below tells of just such a terrible experience, and makes this fear of consciousness during anesthesia very real.
The video above tells of spectacularly horrible experiences. But not all experiences of consciousness during general anesthesia are nightmares such as this. Some people undergo experiences where they can hear the surgeon and other, built feel no pain. Some people even tell of undergoing out-of-body experiences during general anesthesia. How can these very different types of experiences during general anesthesia be explained?
To understand the phenomenon of consciousness, or awareness during general anesthesia, it is first necessary to understand the types of drugs used during general anesthesia. Modern general anesthesia uses three separate categories of drugs to provide the triad of general anesthesia.
Yet, even though unconscious due to general anesthesia with this standard combination of these three categories of drugs, people are still able to feel touch, to feel movements, to see light, to hear, and to smell (Banoub 2003, Thornton 1998). Yet they remember none of these things upon awakening, because of the effects of anesthetic drugs upon memory. Anesthesiologists always monitor many different body functions during anesthesia to determine whether the patients under their care are in good condition, are asleep, adequately paralyzed, or receive adequate amounts of painkilling drugs. Extra doses of these drugs are administered when required to provide extra muscle relaxation, painkilling, or to deepen the level of unconsciousness. Unfortunately, about 1-2 people per 1000 people undergoing general anesthesia experience various degrees of awareness or actual full consciousness under general anesthesia (see articles in Wikipedia on Awareness, Sebel 2004, RCOA 2008).
Not all experiences of awareness during anesthesia are distressing, painful or horrific. In fact there are several different experiences of awareness during anesthesia that are determined by the effects of the drug combinations used in modern general anesthesia. These different drug combinations explain all the horrific experiences, the partially conscious experiences, the fully conscious experiences, as well as the sometimes even wondrous conscious experiences of people under general anesthesia.
The brain function of a person who awakens while supposedly under general anesthesia is abnormal, and this, combined with the effects of the other anesthetic drugs can also induce many strange and seemingly paranormal experiences such as out-of-body experiences, near-death experiences, and the feeling of falling into the "pit of hell". So how do anesthesiologists asceratin whether a person is conscious or unconscious during general anesthesia?
The mainstays of monitoring and detecting awareness during general anesthesia still remain suspicion, the bodily reactions of the person, and supplementation of these things with diverse monitors. What do I mean by suspicion and the reaction of the person's body?
Nowadays in modern countries, suspicion, experience, and reactions of the person's body to surgery are often supplemented with electronic monitors purporting to accurately measure the level of consciousness, or depth of anesthesia. Unfortunately, none of these highly advanced electronic devices are 100% accurate, which is why some people are conscious during general anesthesia, even though the brain function monitor or EEG (electroencephalogram) indicates they were unconscious's at the time (see articles on reliability of monitoring depth of anesthesia by Avidan 2008, Bruhn 2006). This is why professional associations of anesthesiologists in nearly all countries, (including the USA), while acknowledging the utility of these measures of consciousness, always recommend they not be relied upon 100%, and that anesthesiologists must also use experience and common sense to gauge the level of consciousness (see extensive review and recommendations in ASA 2006). The wondrous story of the musician, Pam Reynolds, is the best known account of a person who was conscious during general anesthesia, even though the brain monitoring indicated she was unconscious (click here to read an extensive analysis of the fascinating Pam Reynolds awareness experience).
A person who says they were conscious during an operation performed under general anesthesia is not hysterical or insane. They may very well have been conscious. Careful study of each story, together with an analysis of the anesthetic chart and the surgical procedure, often reveals the time period during which the period of consciousness occurred. The same considerations also apply to people reporting undergoing an apparently paranormal experience while seemingly unconscious during general anesthesia. All such experiences provide wonderful illustrations of the ways the functioning of the bodies of different individuals interact with the effects of surgery and anesthetic drugs. These are sometimes humbling events for the anesthesiologist, but are always to be taken seriously as learning moments for the true professional.