It is not uncommon for older adults to have a change in mental status or to go through a stage of confusion after a general anesthetic. The cause of deterioration in mental ability is unknown. In some cases dementia appears to be triggered by the shock to the body of anesthesia and surgery. It may be a passing phase with complete recovery, although this can take weeks to months.
Mood change after surgery has been reported in adults aged 85 years and older. Sometimes impaired thinking occurs, too. In fact, one out of four adults in this age range have both depression and decreased mental processes.
esearchers aren't sure why this happens. It does seem as though patients with many other health problems have poorer result after surgery. Talk to his doctor about your concerns. Medical treatment may help.