To find out the relationship between various risk factors and post-operative delirium in elderly patients with hip fractures.

Out of 135 patients older than 65 years old who underwent the surgery for hip fracture in our department, between the periods of March 2003 to March 2005, 14 patients (10.4%) developed post-operative delirium and 121 patients (89.6%) did not. We studied risk factors of post-operative delirium in two groups.

In chi-square test between delirium group and non-delirium group, the patients were more likely to develop post-operative delirium if they had previous episodes of delirium, abnormal cognitive function, low walking ability before admission, high dependency on ADL (Activities of Daily Living), other medical accompanying diseases, history of dementia, post-operative hypoxia, post-operative electrolyte imbalance, low post-operative hemoglobin and hematocrit, low post-operative albumin and were older than 75 years old (p<0.05). Sex, type of fracture, anesthesia and the time between admission and operation did not show much difference between the two groups.

The risk factors of postoperative delirium in elderly patients with hip fracture have a tendency to be multifactorial. Therefore, we conclude that being prepared by thorough understanding of the risk factors and their relationships will help prevent post-operative delirium and result in good postoperative prognosis.