Older patients who undergo anesthesia and surgery have a significantly increased risk for dementia, a large population-based study shows.
Investigators at Taipei Veterans General Hospital in Taiwan found that patients older than 50 years who underwent anesthesia for the first time had nearly a 2-fold increased risk for dementia, mainly Alzheimer's disease, compared with nonanesthetized patients.
"The results of our nationwide population-based study suggest that patients who undergo anesthesia and surgery may be at increased risk of developing dementia. Anesthesia and surgery are inseparable in clinical settings. Thus, it is difficult to establish whether the increased risk of dementia development we observed was attributable to the anesthesia per se, the surgical process, or both," principal investigator Jong-Ling Fuh, MD, said in a statement.
The study was published online July 25 in the British Journal of Psychiatry.
Although generally considered safe, there is growing concern that anesthetic drugs may have neurodegenerative complications.
The investigators point out that in vivo studies and imaging studies have shown that "inhaled anesthetic agents can promote amyloid β peptide (Aβ) peptide oligomerisation and enhance Aβ-induced neurotoxicity."
Other potential mechanisms of anesthetic-induced neurotoxicity include calcium dysregulation.
The researchers note that postoperative confusion/decline is generally thought to be short-lived, with normal cognition returning within a few days. However, they add that in some cases, it can last for weeks.
"Although anesthesia and surgery have provided immeasurable health and social benefits, our observations in this piece of research highlight the need for further studies to understand the association and causality between anesthesia with surgery and subsequent dementia," said Dr. Fuh.