Anesthesia involves risks and potential complications. These are the result of combined factors, from the patient’s age and condition to the physical stress of a procedure to the suppression of normal body functions. That’s why professional medical associations recommend having an anesthetist present throughout any procedure that uses anesthesia.
Achieving the Right Depth of Anesthesia
Too little sedation...
can lead to patient awareness, in which the patient is conscious during a medical procedure. Narcotics used to block pain may reduce or eliminate muscle movement, so the patient is unable to move or speak—and may feel anything from concern to terror.
Too much anesthetic...
and the patient may have more trouble during recovery. Problems range from slower recovery to long-term memory loss to elevated risk of death six months after surgery. While there is no direct cause and effect for these outcomes, the correlation is high enough that anesthetists take these risks into account.
Traditional methods of monitoring depth of anesthesia include clinical signs, lower esophageal contractility, and heart rate variability. These methods depend on the expertise of each anesthetist, and on the standard of care for each facility.
Clinicians recognize the potential value of monitoring depth of anesthesia, and medical device companies have developed several technologies for doing so over the past 30 years. Most of these measure brain electrical activity (EEG). One drawback to this approach is interference: Electromyography (EMG) signals, especially in pediatric patients, can distort EEG readings.
One device uses proprietary signal processing algorithms to detect and classify EEG. The Narcotrend Compact-M monitor applies a scale of 100 (conscious) to 0 (very deep hypnosis, EEG suppression) to help clinicians adjust anesthesia according to patient age. The Narcotrend Compact-M monitor has an age-related index which allows for greater specificity in all patient demographics.