Being a bit foggy in the brain during the weeks or months after major surgery is a reality for many aging adults. But it’s not a certain sign of any lasting problems with their mental health such as dementia or Alzheimer's disease.
A recent study found no link between the use of general anesthesia and developing dementia. Study authors suggested that there was no valid basis for previous fears about such a link.
Researchers made those conclusions after studying the medical records of surgical patients who were at least 45 years old.
David Warner, MD, a pediatric anesthesiologist, was one of the Mayo Clinic researchers who analyzed medical records of almost 2,000 surgical patients.
"It's reassuring we're adding to the body of knowledge that there is not an association of anesthesia and surgery with Alzheimer's," Dr. Warner, a pediatric anesthesiologist, was quoted as saying in a Mayo Clinic press release.
"There are a lot of things to worry about when an elderly person has surgery,” Dr. Warner continued. “But it seems that developing Alzheimer's isn't one of them."
Previous concerns that anesthesia could lessen a post-surgery patient's memory, understanding and other brain functions were based on several studies in which animals who had been given anesthesia later developed brain lesions similar to those found in Alzheimer’s patients, the researchers concluded.
Through the Rochester Epidemiology Project, the researchers had access to all Olmstead County patient records.
Also using the Mayo Clinic Alzheimer's Disease Patient Registry, which includes all county residents who have been diagnosed with Alzheimer’s, the researchers analyzed records of roughly 900 Olmstead County adults who were at least 45 years old and had dementia between 1985 and 1994.
The researchers compared those patients to roughly 900 adults of similar age from the same county during the same period but who did not have dementia. Members of the second group were followed for up to five years after they received anesthesia before surgery.
About 70 percent of people in both groups required general anesthesia before surgery.
The study concluded that getting anesthesia did not worsen the dementia of those already living with dementia, and it did not cause dementia in those who did not already have dementia.
The researchers cautioned that Olmstead County’s residents are mostly white, while those in other racial groups also suffer with dementia.
They also said their research did not take into account other key factors such as educational achievement, which prior studies also have said is linked to whether or not a person gets dementia.
This study was published in May in Mayo Clinic Proceedings.
Grants from Mayo Clinic College of Medicine Department of Anesthesiology and Rochester Department of Anesthesiology, an arm of the Mayo Clinic, funded the research.
The researchers did not declare any conflicts of interest.