Postoperative cognitive dysfunction is a common complication during postoperative period，especially in elderly patients. It is characterized by cognitive decline, inattention and abnormal mental status following surgery. The presence of postoperative cognitive dysfunction is independently associated with poor recovery, increased hospital length of stay and increased mortality.~Tropisetron is a 5-HT3A receptor antagonist and is widely used to treat postoperative nausea and vomiting. Previous studies found that tropisetron has positive effect on cognitive function.~We have designed a randomized, double-blind, placebo-controlled trial to determine if tropisetron has a positive effect on postoperative coginitive function in patients after cardiac surgery. Several assessements which are related to delirium, cognitive function, sleep and functional status, blood sample collection and EEG recordings will be involved in the trial. Moreover, we have assumed a few long-term follow-ups.~Given the complexity of the trial, we have decided to implement a pilot trial to assess the feasibility and provide vital data for future formal trial.
The purpose of this study is to assess the feasibility of a randomized, double-blind, placebo-controlled pilot trial evaluating the effect of tropisetron on prevention of postoperative cognitive dysfunction in patients after cardiac surgery.