Awareness Under Anesthesia
|Written by Dr. Nina Radcliff|
SeniorLiving.Org Expert on Anesthesia | Pharmacology | Leadership
During the Civil War, anesthesia was provided by dipping cloth in liquid chloroform or ether and holding it over a patient’s nose and mouth. There are some obvious concerns with this technique and fortunately anesthesia has come a long way since then. 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 that are stored in memory. Every week I have at least one patient express concern about waking up during surgery. I have to admit, I wish they were this concerned about quitting smoking, abstaining from alcohol, exercising or eating healthy. Fortunately, intraoperative awareness is extremely rare and studies have shown an estimated incidence of 0.007-0.91 percent. However, this value is not zero and our patient’s concerns and fears are real.
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, awareness about intraoperative awareness is a good thing, especially when it is discussed factually and not sensationalized. Here are some facts every patient undergoing general anesthesia should know:
- General anesthesia is a drug-induced state that interrupts the brain’s ability to process and remember information from the patient’s surroundings.
- While you are asleep, your anesthesiologist utilizes sophisticated technology to deliver specific dosages of anesthetic medications (no cloth over the nose and mouth). They also carefully and vigilantly monitor your heart rate, blood pressure and breathing pattern to help gauge the depth of anesthesia. Specialized brain function monitors can assess electrical activity and possibly aid with decision-making. However, these monitors have limitations and the decision to use them should be individualized to your case.
- It is possible to remember events or conversations in the operating room before going to sleep or after awakening 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, have lost a significant amount of blood, or are undergoing emergency surgeries or Cesarean sections. These patients may not be able to tolerate the blood pressure lowering effects of anesthetic medications. Your anesthesiologist may face the difficult choice between keeping the patient (or baby) alive and unharmed versus keeping them asleep. 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.
Doctors and researchers have shown when intraoperative awareness is identified early and appropriately managed, there is a decreased occurrence of sleep disturbances, anxiety or post-traumatic stress disorder (PTSD) and patients are less likely to avoid future medical care. If you feel you may have experienced awareness under anesthesia, alert your anesthesiologist as soon possible. He or she should obtain a detailed account of your experience and appropriately document it in your chart and report it to the hospital. When appropriate, you may be offered counseling or psychological support. You should be informed of the Anesthesia Awareness Registry and encouraged to join by calling (206) 616-2669 and requesting a paper enrollment packet.
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, in particular pain, anxiety, and sleep medications. Be forthright about how much alcohol you drink (or if you use any illegal drugs) and the approximate the number of cans, glasses or ounces you consume in a day or week. Anesthetic medications act on the same brain receptors as a number of these medications or alcohol and you may require higher dosages. If you have encountered, or believe you have encountered awareness under anesthesia, this should also be disclosed so your doctor can try to figure out why it happened and make specific attempts to prevent it from happening again. Be clear about what type of anesthesia you will be receiving because in some instances, sedation may be most appropriate and safest. And finally, ask the anesthesiologist if you have an increased risk.
Updated: Feb 18, 2013