Postoperative Change in Mood and Cognition of the Elderly Patients

ABSTRACT

OBJECTIVES: Surgery is being offered to an increasing proportion of the over 60s and postpoerative cognitive dysfunction may occur in the elderly. We investigated that age could be a risk factor. The confounding effects, such as learning effect due to repeated testing and the effect of distress on the test performance, were controlled for by control group. METHOD: Twenty patients aged at least 60 years completed neuropsychological test 1 day before and 1 week after surgery. We measured Mini-Mental Status Examination (MMSE), digit span, 'A' test, similarity test, Digit Symbol Substitution Test (DSST), Beck Depression Inventory (BDI), Montgomery-Asberg Depression Rating Scale (MADRS) and State Anxiety Inventory (SAI). The authors compared postoperative cognitive dysfunction by neuropsychological test in the elderly patients with those in the control group. RESULTS: One week after operation, there was no cognitive impairment compared with before operation. Advanced age might not contribute to cognitive impairment except DSST. And there was an improvement in the scores for BDI and SAI in the control group only. We did not find a significant relation between early postoperative cognitive dysfunction and mood state before operation. Because the elderly patients had lower educational level and more depressive than control group before operation, we thought that the deterioration of DSST did not happened with operation, but by insufficiency of learning effect in the elderly patients. CONCLUSION: Cognition in the elderly patients was not impaired significantly after operation when attention was paid to the known perioperative influences on mental function.