Brain Under Anesthesia Is in Reversible Coma, Review Finds
Insights gained from study of anesthesia may add to knowledge base of sleep disorders, coma
WEDNESDAY, Dec. 29 (HealthDay News) -- The brain under general anesthesia is not "asleep," but rather is in a state that is actually a reversible coma, according to a review article published in the Dec. 30 issue of the New England Journal of Medicine.
Emery N. Brown, M.D., Ph.D., of the Massachusetts General Hospital and Harvard Medical School in Boston, and colleagues discuss the clinical and neurophysiological features of general anesthesia and their relationships to sleep and coma. They focus on the neural mechanisms of unconsciousness induced by certain intravenous anesthetic drugs that could eventually lead to new insights into general anesthesia and improved diagnosis and treatment for sleep abnormalities and emergence from coma.
According to the researchers, a brain that has been fully anesthetized is much more similar to the deeply unconscious low-brain activity observed in coma patients than to the brains of sleeping individuals. They determined that general anesthesia is a drug-induced, and therefore reversible, coma. The researchers note, however, that emergence from general anesthesia usually takes minutes, while recovery from coma -- if it occurs at all -- requires hours to years.
"In conclusion, a better understanding of sleep and coma may lead to new approaches to general anesthesia based on new ways to alter consciousness, provide analgesia, induce amnesia, and provide muscle relaxation," the authors write.
One author disclosed plans to file a patent for a drug that can induce recovery from general anesthesia; another author disclosed a financial relationship with IntElect Medical Inc.