Anesthetic Awareness Fact Sheet

Patient awareness under general anesthesia (or anesthetic awareness) is a rare condition that occurs when surgical patients can recall their surroundings or an event—sometimes even pressure or pain—related to their surgery while they are under general anesthesia. Severe cases of anesthetic awareness happen infrequently, but research is ongoing to determine the causes of awareness and prevent it from happening.
  • Definition of awareness. Under general anesthesia, a patient is given medications intended to cause unconsciousness and relieve pain. If the medication to render the patient unconscious fails, awareness occurs. In other words, the patient wakes up, becomes aware of certain events occurring during the surgery, and may recall some or all of the events. Further, if the medication to relieve pain fails or is inadequate, the patient may feel pain while awake. Finally, cases involving general anesthesia often require the patient to be given medication intended to prevent movement. In very rare instances, the sleep and pain medications fail while the paralytic agent does not, making it virtually impossible for the patient to communicate this dire situation to the anesthesia providers.
  • Frequency of awareness. Anesthesia awareness occurs infrequently, and the duration and severity vary. Patients may or may not feel pain. Some patients experience a feeling of pressure. It has been estimated that roughly one patient per thousand receiving general anesthesia experiences some level of awareness, usually fleeting. It is important for patients to understand that severe awareness experiences are highly unusual.
  • Patients should NOT be afraid! The remote possibility of experiencing awareness should not deter patients from having needed surgery. The plain truth of the matter is this: Modern surgery is only possible through the miracle of anesthesia.
  • Anesthesia safety. Anesthesia today is safer than it has ever been due to advances in technology and pharmacology, as well as more stringent practice standards and educational requirements for anesthesia providers. A 1999 report by the Institute of Medicine titled "To Err is Human" indicated that anesthesia is nearly 50 times safer than it was in the early 1980s.
  • Certified Registered Nurse Anesthetists (CRNAs). These advanced practice nurses are anesthesia professionals who safely administer approximately 32 million anesthetics each year. CRNAs provide anesthesia care for all types of surgeries and other procedures, including open heart and transplants.
  • CRNAs: At your side, on your side. CRNAs are hands-on caregivers who take pride in advocating for their patients. They stay with their patients throughout their surgeries, diligently monitoring their vital signs and adjusting their anesthetics as needed.
  • Causes of awareness. Despite the dramatic improvements in the quality of today’s anesthesia care, awareness during general anesthesia can still occur for a variety of reasons. Common causes of anesthesia awareness are inadequate anesthesia and equipment failure or misuse.
  • High-risk surgeries. In some high-risk surgeries such as cardiac, trauma, and emergency cesarean deliveries, using a deep anesthetic may not be in the best interest of the patient. In these and other critical or emergency situations, awareness might not be completely avoidable. 
  • Lasting impact. A minority of patients who experience anesthesia awareness may develop posttraumatic stress disorder (PTSD), which is associated with repetitive nightmares, anxiety, irritability, and preoccupation with death.
  • Preventing awareness. Research into the causes and prevention of anesthesia awareness is ongoing. Anesthesia providers combine their clinical judgment with the use of different monitoring technologies to ensure that their patients are unconscious and pain-free during surgery.  Brain monitoring devices can be used to measure depth of consciousness, and are available in the majority of hospitals across the United States. Studies have shown that these monitors can help anesthesia providers further reduce the risk of awareness, although they alone are not a guarantee of preventing awareness.
  • Patient/anesthesia provider communication—before surgery. Patients should have the opportunity to meet with their anesthesia provider before surgery to discuss the remote possibility of awareness, the approach to anesthesia that will be used, how they will be monitored during surgery, if the anesthesia provider they are meeting with will be the anesthesia provider who stays with them during surgery, and any other concerns they might have. It is important for patients to be honest about medications (including herbal supplements) they are taking, alcohol and drug consumption, physical conditions, and other factors that could influence their body’s reaction to anesthesia. 
  • Patient/anesthesia provider communication—after surgery. Patients who believe they have experienced anesthesia awareness should be encouraged to discuss their experience and their feelings about the experience with their anesthesia provider.
  • "Awake" movie. "Awake" is fictional entertainment that exploits anesthetic awareness as a plot device. Viewers should remember that while patient awareness under general anesthesia does occur, severe cases such as the one depicted in "Awake" are highly unusual.