French survey links general anaesthesia to increased risk of dementia in elderly

Elderly patients who receive general anaesthesia are 35 per cent more likely to develop dementia several years later, according to a new abstract by a French researcher.

The lead researcher is Dr. Francois Sztark with the Institut National de la Sante et de la Recherche Medicale (INSERM). He concludes there is a link between elderly patients who experience a decline in cognitive function following major surgery.

His abstract will be presented at the annual congress of the European Association of Anaesthesiology in Barcelona next month.

The University of Bordeaux professor found that patients 65 years and older had a 35 per cent increased risk of developing a dementia compared with patients who did not have a history with anaesthesia.

“These results are in favour of increased risk for dementia several years after general anaesthesia,” Sztark said in a news release on Friday.

Dementia and Alzheimer’s disease slowly erode a person’s memory and reasoning abilities. According to the Alzheimer Society, there are approximately 500,000 Canadians suffering from dementia.

The link between dementia and general anaesthetics may be a result of neural tissue inflammation, leading to postoperative cognitive dysfunction (POCD) and/or precursor symptoms associated with Alzheimer’s disease, according to several studies cited in Sztark’s research.

POCD is a common complication amongst elderly patient who receive general anaesthetics for major surgery.

“Recognition of POCD is essential in the perioperative management of elderly patients,” Sztark said. Large clinical studies are needed, he says, to assess to potential neurotoxicity in humans.

In his study, data collected from 1999 to 2001 from a sample of 9294 people aged 65 years and over was used.

Participants were interviewed at the two, four, seven and 10 year mark and were asked if they had received general anaesthetics.

Participants were also given a complete cognitive evaluation paired with a screening of dementia. All of the participants were residents of Bordeaux, Dijon or Montpellier in France.