Postoperative delirium: perioperative assessment, risk reduction, and management.

Postoperative delirium is a relatively common and serious complication. It increases hospital stay by 2-3 days and is associated with a 30-day mortality of 7-10%. It is most prevalent in older patients, those with existing neurocognitive disorders, and those undergoing complex or emergency procedures. Preclinical and clinical research in recent years has uncovered more about the pathophysiology of postoperative delirium and may yield more potential therapeutic options. Using the enhanced recovery pathway framework of risk stratification, risk reduction, and rescue treatment, we have reviewed the current clinical evidence on the validity of delirium prediction scores for the surgical population, the effectiveness of perioperative delirium risk reduction interventions, and management options for established delirium. Effective perioperative interventions include depth of anaesthesia monitoring, intraoperative dexmedetomidine infusion, and multimodal analgesia. Choice of general anaesthetic agent may not be associated with significant difference in delirium risk. Several other factors, such as preoperative fasting, temperature control, and blood pressure management have some association with the risk of postoperative delirium; these will require further studies. Because of the limited treatment options available for established delirium, we propose that risk assessment and perioperative risk reduction may be the most effective approaches in managing postoperative delirium.