How Do You Recover from Anesthesia?

By Jane Farrell

A new study has found important clues about the process the brain uses to “navigate” back to consciousness after being on anesthesia.

Earlier research has revealed some elements of brain activity under anesthesia, but until now there haven’t been any findings on the navigation process out of anesthesia.

In the new study, Dr. Andrew Hudson, an assistant professor of anesthesiology at the David Geffen School of Medicine at UCLA, and colleagues analyzed the brain’s electrical activity in rodents. After the rodents inhaled the anesthesia isoflurane, the investigators slowly decreased the amount of anesthesia. Via electrodes placed in various areas of the brain, they observed its changes as the subjects came out of anesthesia.

The researchers found that the brain activity occurred in discrete clumps, or clusters, and that the brain did not jump between all of the clusters uniformly. Hudson said that the patterns depended on the amount of anesthesia the subject was getting. Some of the activity patterns connected patterns that were consistent with deeper anesthesia to those observed under lighter anesthesia.

“Recovery from anesthesia, is not simply the result of the anesthetic ‘wearing off’ but also of the brain finding its way back through a maze of possible activity states to those that allow conscious experience,” Hudson said. “Put simply, the brain reboots itself.”

The findings, published in the Proceedings of the National Academy of Sciences, could lead physicians to re-examine how they monitor anesthesia in the operating room. And doctors observing the patterns may be able to predict recovery from other consciousness disorders such as coma.