General anesthesia makes it possible for millions of patients each year to undergo lifesaving surgeries while unconscious and free of pain. But the 176-year-old medical staple uses powerful drugs that have stoked fears of adverse effects on the brain — particularly if used in high doses.
New findings published June 10 in the Journal of the American Medical Association (JAMA), however, support an earlier study that indicates that anesthesia is no more hazardous for the brain at higher doses than at lower doses, according to the researchers.
The new study reports results of a multicenter clinical trial of more than 1,000 older patients who underwent cardiac surgery at four hospitals in Canada. Researchers at these hospitals, in partnership with colleagues at Washington University School of Medicine in St. Louis, found that the amount of anesthesia used during surgery did not affect the risk of postoperative delirium — a state that may contribute to long-term cognitive decline.
“Concern that general anesthesia harms the brain and causes both early and lasting postoperative cognitive disorders is a major reason that older adults avoid or delay life-enhancing procedures,” said Michael S. Avidan, MBBCh, the Dr. Seymour and Rose T. Brown Professor of Anesthesiology and head of the Department of Anesthesiology at Washington University. “Our new study contributes to other compelling evidence that higher doses of general anesthesia are not toxic to the brain. Dispelling the misleading and pervasive message that general anesthesia causes cognitive disorders will have major public health implications by helping older adults make wise choices regarding essential surgeries, which will promote and sustain healthier lives.”