Q: I am having surgery soon. How is the doctor going to know I am really asleep?
A: Intraoperative awareness under general anesthesia is a very rare occurrence, with a reported incidence of 0.1-0.2 percent. Many of those instances occur when trauma or emergency cardiac surgery is performed and the patient needs to be sedated enough to keep him or her unaware while not depressing the heart and circulatory system. Now that I've got your attention, here is how we can be sure the patient is asleep for surgery: continuously measure the amount of anesthetic gas being exhaled by a patient to determine the level of sedation he/she is receiving; monitor heart rate, blood pressure, and examine for signs of perspiration or movement; give amnestic drugs such as Versed which keeps the patient relaxed and unable to form memory; and use a newer device called a BIS monitor, a modified EEG which when applied to a patient's forehead during surgery can relay continuously updated levels of hypnosis/sedation the patient is receiving. These advances help us know the patient is asleep and keep him/her safe from awareness during surgery.
-- Dr. Corey Carpenter, Anesthesia Associates; member, Chattanooga-
Hamilton County Medical Society
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