The study found that many of the young, middle-aged and elderly patients experienced postoperative cognitive dysfunction (POCD) at the time they left the hospital. But three months later, those aged 60 and older were more than twice as likely to exhibit POCD. Those with POCD at both the time of hospital discharge and three months after surgery also were more likely to die within the first year after surgery, Monk said.
The large difference in the prevalence of POCD between what we termed the elderly -- those aged 60 and over -- and the younger groups we were studying validates the general perception that the elderly are predisposed to cognitive impairment after major surgery, Monk said. POCD was more common among those patients with lower educational level and a history of a stroke that had left no noticeable neurologic impairment.
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 reasons why cognitive decline is associated with early death are not completely understood, but its possible that patients with prolonged cognitive dysfunction might be less able to take medicines correctly or may not recognize the need to seek medical care for symptoms of complications, Monk said.
Studies on normal aging have shown a link between abrupt cognitive decline and early death, so we speculated that surgery-related cognitive dysfunction might have the same effect, she said.
Why some patients suffer POCD is not known, but one hypothesis is that surgery and the accompanying anesthesia might cause inflammation in the brain that can affect the patients ability to learn, retain or remember information, Monk said.
Now that the implications of long-term POCD are better understood, doctors must devise
|Contact: Lauren Shaftel Williams|
Duke University Medical Center