The effect of ondansetron on postoperative delirium and cognitive function in aged orthopedic patients.

BACKGROUND: Postoperative delirium and cognitive dysfunction are common in hospitalized patients. The aim of this study was to investigate whether postoperative ondansetron administration has a favorable effect on postoperative delirium and 30th day cognitive function and pain in patients undergoing surgery with general anaesthesia due to femoral or hip fracture.

METHODS: A hundred and six patients aged >40 years old scheduled for a femoral or hip fracture rehabilitation surgery, were randomized on a double-blind protocol to receive postoperatively 4 ml of either ondansetron 8 mg (Group A) or placebo (Group B) daily i.v. for five days. Each patient was evaluated preoperatively and on the 2nd, 3rd, 4th and 5th day postoperatively with Confusion Assessment Method test, and preoperatively and on the 30th day postoperatively using a sensitive battery of neuropsychological, functional and pain tests.

RESULTS: Patients of both groups did not differ preoperatively significantly in their basic characteristics and predisposing factors associated with postoperative delirium and cognitive dysfunction. The results showed that postoperative administration of ondansetron was followed by a lower incidence and duration of postoperative delirium and improved postoperative neurocognitive function on the 30th postoperative day, regardless of age or history of stroke. This was accompanied by a significant better postoperative functionality and less pain.

CONCLUSION: The postoperative ondansetron administration seems to protect and might improve the cognitive function in patients undergoing surgery under general anesthesia. Ondansetron also seems to release analgesic effects.