Cognitive decline after major noncardiac operations: a preliminary prospective study

Background. Cardiac operations frequently are complicated by postoperative cognitive decline. Less common and less studied is postoperative cognitive decline after noncardiac surgery, so we determined its incidence, severity, and possible predictors. Methods. Twenty-nine patients who had thoracic and vascular procedures were studied. A neurocognitive test battery was administered preoperatively and 6 to 12 weeks postoperatively. A change score (preoperative minus postoperative) was calculated for each measure in each individual. Cognitive deficit (a measure of incidence) was defined as a 20% decrement in 20% or more of the completed tests. The average scores of all tests and the average decline (a measure of severity) were determined. Results. The incidence of cognitive deficit was 44.8%. Overall the severity of the decline was an average of 15% decline. In the 44.8% of patients who had cognitive deficit, the severity was 24.7%. Multivariable predictors of cognitive decline were age (for incidence and severity) and years of education (for severity). Conclusions. Cognitive decline after noncardiac operations is a frequent complication of surgical procedures. The severity could preclude successful return to a preoperative lifestyle.