Anesthesia awareness is an exceptionally rare complication of anesthesia, where patients have some sense of what is occurring while anesthetized, but are usually unable to communicate that awareness to medical providers. Some types of anesthesia, like conscious sedation, always have a degree of awareness, which may be necessary for patients to follow commands. In other cases, this awareness is unintended; the patient should be fully unconscious but isn’t, and he may hear, smell, feel or see. This most occurs if the patient is simultaneously immobilized using paralytic drugs, which means he has no way to communicate his aware status.
Some horror films sensationalize anesthesia awareness and make many people afraid they’ll encounter it as part of surgery with general anesthesia. It’s estimated that about one in one thousand people experience at least transient awareness during surgery, but many of them may not remember it when they awake, since some of the medications they receive cause amnesia. In other cases, awareness does last longer, and though it may not be as sensational as a horror film case, it can be traumatizing and result in the need for significant therapy to treat syndromes like posttraumatic stress. Long-term awareness may only occur in a tiny percentage of the already very small percentage of people who experience anesthesia awareness.
One of the greatest risk factors for anesthesia awareness appears to be using drugs that paralyze the body. This can make a person motionless and unable to communicate, so that if other drugs creating unconsciousness and freedom from pain are not working, the person is still unable to tell surgeons or anesthesiologists. The careful monitoring of other vital signs might indicate if a patient is experiencing awareness, fear, or pain. Sudden increases in blood pressure, heart rate, respiration or symptoms like excess perspiration could suggest awareness, and medications could be adjusted accordingly.
Other possible causes of anesthesia awareness are physician error, malfunction of equipment, paradoxical drug reactions, or interactions between substances a patient is using and anesthetics chosen. Again, it’s important to stress that this circumstance is very rare. Those concerned about it should certainly talk to their anesthesiologist prior to a surgery, and it is very important for patients to be forthcoming about any drug reactions that have occurred in the past, and any drugs, substances or supplements presently used.
As mentioned, some people experience brief awareness they won’t remember, but a few do have prolonged periods of awareness, and these can be incredibly traumatic, particularly if pain is felt. There is no way to stop it and the patient may feel like he or she is being tortured with no escape. Understandably, this leads some people to develop symptoms of posttraumatic stress.
This leads to the recommendation that patients address anesthesia awareness shortly after surgery. If it was traumatic, seeking psychotherapeutic help early is encouraged. People may also find support groups online for those who have experienced this challenging situation.