Awareness about intraoperative awareness

Awareness about intraoperative awarenessA guest column by the American Society of Anesthesiologists, exclusive to

During the Civil War, anesthesia was provided by dipping cloth in chloroform or ether and holding it over a patient’s nose and mouth. Today, anesthetic medications are delivered in a controlled (and more civil) manner through specialized devices to provide unconsciousness for surgery.

Over the last several years, there has been significant media coverage of “waking up” during surgery. Also known as intraoperative awareness, this implies that during a period of intended general anesthesia, the brain is aroused by stimuli stored in memory. Every week I have at least one patient express concern about waking up during surgery. Fortunately, intraoperative awareness is extremely rare and, according to a new study by the Royal College of Anaesthesists and the Association of Great Britain, only one in 15,000 patients experience this phenomenon.

Media coverage of this issue has resulted in the medical community proactively addressing and researching methods to prevent, identify and treat intraoperative awareness. In fact, mindfulness about intraoperative awareness is a good thing, especially when it is discussed factually and is not sensationalized. Here are some facts every patient undergoing general anesthesia should know:

  • While you are asleep, your anesthesiologist uses sophisticated technology to deliver specific dosages of anesthetic medications. They also carefully and vigilantly monitor your heart rate, blood pressure and breathing pattern to help gauge the depth of anesthesia.
  • It is possible to remember events or conversations in the operating room before going to sleep or after waking from your surgery. However, this does not constitute awareness under anesthesia. Additionally, some procedures are performed with sedation (e.g. colonoscopies, cataracts, biopsies) instead of general anesthesia.
  • “Not giving enough” anesthesia is not the only cause of intraoperative awareness. More commonly, awareness occurs in patients who have impaired heart function, lost a significant amount of blood, or are undergoing emergency surgeries or Cesarean sections. Alternatively, patients with chronic pain conditions, alcohol abuse or obesity may have higher drug requirements.
  • Not all awareness is the same. It can vary from specific and vivid to dream-like memories of your surgery. Most patients who have experienced awareness did not feel pain, although some described experiencing pressure.

As a patient, there are a number of things you can do that may decrease your risk of intraoperative awareness:

  • During your preoperative interview, it is important to provide an accurate list of medications, particularly pain, anxiety and sleep medications.
  • Be forthright about how much alcohol you drink and the approximate the number of cans, glasses or ounces you consume in a day or week, or if you use any illegal drugs.
  • Ask your anesthesiologist if you have a unique or increased risk for anesthesia awareness.

Doctors and researchers have shown there is a decreased occurrence of anxiety and patients are less likely to avoid future medical care when intraoperative awareness is identified early and appropriately managed. If you feel you may have experienced awareness under anesthesia, alert your anesthesiologist.

Nina Singh-Radcliff is a member of the American Society of Anesthesiologists’ Committee on Communications. 

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  • Robert Luedecke

    As an anesthesiologist, I can say this is an outstanding article. Awareness during general anesthesia in a healthy person is very uncommon. In my 29 years in practice, none of my patients have experienced it.

  • LastoftheZucchiniFlowers

    I believe this represents the old conundrum of storage vs. retrieval vis a vis memory. I suspect that is is quite likely that ‘awareness’ occurs commonly, but recollection of the event is quite transitory for the patient; like remembering dreams that awaken us in the middle of the night. The awareness is acute in that moment – yet gone by morning’s light. Does the loss of the memory of ‘awareness’ make it less significant? A complex issue, to be sure. As they say, ‘more research is needed on this subject’. A rich field to be mined by research scientists / brain ‘mappers’?

  • Robin Taylor

    Dr Singh-Radcliff, how very fortunate for you that you have never experienced this horrifying torture. I did, and still remember it vividly years later, during a repeat Caesarean section. Imagine being awake and aware,and being unable to communicate because you’ve been paralyzed by drugs. Can you imagine what it’s like to KNOW that you are not breathing? My position on the cold metal table, with both arms spread and tied down for IV’s, was horizontal crucifixion. Imagine feeling a knife cutting open your belly (it was a vertical incision, and strangely, the cutting knife feels hot and burning), your own warm blood over your skin, and the gush of the warmer amniotic fluid. Feel the only response you can make, the rapid heart heartbeat responding to the incredible stress of a major bodily injury, spurting more of your blood from your body. Imagine, for a moment, what it’s like to hear one man by your head say “She’s not out!” and a man near your belly say “I know, but you can’t give her more until we get the baby out” and be thinking “Hurry up already!” When I heard my son cry, my thought was not joy at his birth, but “Put me out you !@#$%&*!” then blessed blackness. Only moments–I do not know what the actual time interval was–later, I was awakened by the sensation of multiple stabbings through the skin of my ravaged belly. Blackness again. I awoke again, being rolled off the cold operating table onto a gurney–which was warmer, and not covered with my blood and fluids–and this time, extubated (which I could feel), I could scream. I heard someone say “Give her Demerol,” and I screamed back “No, give me Dilaudid! I puke Demerol!” Then there was a burning in the vein of my left arm, and I blacked out again. The next time I awoke, again screaming in pain, a nurse came to my bed, saying, “You can’t scream like that! You’re bothering the other patients!” so I vomited oceans of acrid brown fluid all over her, myself, and the floor. Two other nurses came to clean up the mess. I heard someone telling my husband–who had been barred from the OR because I was supposed to be unconscious and therefore not needing his presence–that he could not see me, and if he didn’t leave, she would call Security to remove him.
    Two days later, still in wretched pain, and unable to eat or drink, I was told my son had been moved to the regular nursery after recovering from an episode of hypoglycemia. I finally met my baby son another 3 days later, when I could transfer myself to a wheelchair. The next day, taking the first solid food in nearly a week, I coughed on a missed swallow and the too-tight sutures ripped through the skin, necessitating another trip to the OR for a partial closure of the incision. (I was well-numbed this time)
    Perhaps it’s needless to say that the horrible memory of his birth interfered with bonding with my son; he eventually was taken by my sister and her husband to rear. I aborted the next pregnancy rather than risk a repetition. (Effective contraception was very difficult to obtain in my State of residence at the time, and still is)
    This event is still bright and vivid in my memory, decades after it happened. (Observe the details I can remember) I’ve tried support groups, individual therapy, even hypnosis, and nothing has changed the fear, the terror, the helplessness of those moments, or the anger toward my innocent baby for causing that pain.
    “Anesthesia awareness” is NOT just some transitory sensation, or a time-distorted memory of events before or after a surgery. It is an incredibly traumatizing betrayal of trust. No one acknowledged my pain and suffering; no one expressed any sympathy or offered any comfort; no one even said “I’m so sorry that happened to you.” Instead, when I did ask WHY this happened, I was told there was something wrong with ME that prevented the drugs from working as expected, or that I was just some wimpy person with no pain tolerance.
    I am truly shocked and horrified to see that anesthesia awareness is still discounted, especially when suffered by women.

    • LastoftheZucchiniFlowers

      Where were you that you cannot (could not) get contraception? The article specifically addressed anesthesia awareness being documented during emergency C-sections in ‘not giving enough’. Your story is a tragic one and I hope your baby, who did not cause your pain and was indeed a true innocent in this has been well parented and loved by his aunt and uncle.

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