Older Surgical Patients Face Greater Risk of Cognitive Problems
TUESDAY Jan. 15, 2008 -- People over age 60 are twice as likely to lose memory and mental acuity after elective surgeries than younger adult patients, according to a new study.
These patients are also at higher risk of dying within one year of the surgery if they experience a related mental decline, a Duke University team reported.
However, higher education appeared to protect against the loss of mental ability after surgery, the team add.
"We have known that patients undergoing heart surgery are at risk for cognitive dysfunction -- problems with memory, concentration, processing of information -- but the effects of non-cardiac surgeries on brain function are not as well-understood," lead investigator Dr. Terri Monk, an anesthesiologist at Duke and the Durham Veterans Affairs Medical Center, in Durham, N.C., said in a prepared statement. "Our study found that increasing age put patients in this population at greater risk for cognitive problems. And this is significant, because the elderly are the fastest growing segment of the population. We know that half of all people 65 and older will have at least one surgery in their lifetime."
The team gave memory and information processing tests to more than 1,000 adult patients before elective surgery, when they were discharged, and three months after their surgery. They compared the results with the results of more than 200 similar adults who took the tests at the same times but did not go through surgery.
For the purposes of the study, elective surgeries included joint replacements, hysterectomies and other non-emergency, inpatient procedures.
The researchers found that many of the adults experienced postoperative cognitive dysfunction (POCD) upon being discharged. However, when tested three months later, the patients who were over age 60 were twice as likely to still have POCD. People who had POCD when they left the hospital and still had it three months later were more likely to die within a year of surgery.
The study also found that POCD was more likely among less educated patients and people who had a history of stroke, even without symptoms of impaired brain function.
"Education protected against postoperative cognitive problems, likely because education may provide an opportunity to condition the brain and better equip it to withstand injury, much like physical exercise has a protective effect on the body," Monk said.
The researchers theorized that the loss of thought processes might increase the risk of death because of an interference with the ability to seek or follow medical care recommendations.
The cognitive decline could be a side effect of surgery and anesthesia, which might cause inflammation in the brain, said the researchers, who called for further research into the effect and ways to prevent it.
The study, funded by the U.S. National Institute on Aging, the Anesthesia Patient Safety Foundation and the I. Heerman Foundation, was published in the Jan. 1 issue of Anesthesiology.
To learn more about mild cognitive impairment, visit the Alzheimer's Association.
Posted: January 2008