Furthermore, the researchers reported, 59 percent of patients experienced cognitive decline immediately after surgery. These patients, the researchers found, are at the highest risk for long-term cognitive decline. Three months after surgery, 34 percent of patients had cognitive declines.
"Our study showed that elderly patients experience a high prevalence and persistence of cognitive decline after major, non-cardiac surgery, characterized by early improvement followed by later decline," said Duke anesthesiologist Terri Monk, M.D. She presented the results of the Duke study Oct. 26, 2004, at the annual scientific sessions of the American Society of Anesthesiologists in Las Vegas. "The issue of cognitive decline after surgery in the elderly population is a very important one that has not received adequate study," said Monk.
"From past longitudinal studies of the elderly, we know that any abrupt change in cognition is strongly associated with loss of independence or death," she continued. "Since our studies have demonstrated a high incidence of cognitive decline after surgery, more research is need to better understand the mechanisms responsible for postoperative cognitive decline and to develop interventions to reduce this serious complication."
This pattern of a steep decline in cognitive function after surgery, followed by short-term improvement and a longer term decline, mirrors the findings of an earlier Duke study of patients undergoing heart surgery. That study, the results of which were published Feb. 8, 2001, The New England Journal of Medicine, found that 53 percent of patients suffered from immediate cognitive declines, with 36 percent having declines six weeks after surgery, and 42 percent with declines five years after surgery
Contact: Richard Merritt
Duke University Medical Center