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Brain Function Monitors

What is brain function monitoring?

Brain function monitors measures the very small waves of activity produced by the brain. They are designed to give an additional method of assessing when a patient is unconscious from anesthesia. Brain function monitors have also been called depth of anesthesia monitors. They are only one among the many monitors, such as heart rate, blood pressure, and anesthetic gas monitors that anesthesiologists use to assess the depth of anesthesia.

How do brain function monitors work?

When a person is asleep or anesthetized, brain wave activity is different than when a person is awake. The monitor is attached to the patient’s forehead by taping a strip. This strip detects the brain wave activity which is displayed on a monitor screen. Then the anesthesiologist uses it to assist in assessing the depth of anesthesia besides the other monitors during surgery.

Do brain function monitors reduce anesthesia awareness?

Awareness is difficult to study because it is a rare event. One study (Myles et al., 2004) found that use of a brain function monitor in patients who were at high risk for awareness reduced the number of patients with anesthesia awareness. The people who are at high risk include people with medical conditions or types of surgeries in which only lower doses of anesthesia may be safely given. However, there have not been any studies in people who at low risk for anesthesia awareness. The American Society of Anesthesiologists (ASA) recommended that the decision of whether or not to use a brain function monitor should be made by the anesthesiologist individually for each patient.

Can I request that a brain function monitor be used for my anesthetic?

The brain function monitors are used in many, but not all operating rooms. You should talk about any of your concerns regarding anesthesia, including awareness and brain function monitors with your anesthesiologist.