Impact of Desflurane and Sevoflurane on Postoperative Delirium in Elderly Patients

With increasing life expectancy, more and more patients aged 65 or older will receive general anesthesia. Rapid recovery from anesthesia may reduce the incidence of many postoperative complications, such as postoperative delirium and cognitive dysfunction. Using inhalational anesthetics is the mainstay of general anesthesia. Since they pass readily into the brain, anesthetics are usually recognized as the important cause of postoperative cognitive dysfunction. Studies have shown that inhalation anesthesia may increase the risk of postoperative delirium in elderly patients compared to propofol, but such studies mostly focus on isoflurane and sevoflurane. Concentrations isoflurane caused aggregation of amyloid peptides in cell cultures, indicating that they brought cytotoxicity to the brain; sevoflurane also showed the same cytotoxic effect. However, some studies showed that inhalational anesthetics had a protective effect on postoperative cognitive function. Desflurane is currently known to be the least biotransformation inhaled anesthetic, whose blood-gas partition coefficient is only 0.42. Desflurane is increasingly used in elderly patients in clinical practice. However, it is not clear whether general anesthesia maintained mainly by desflurane reduces postoperative delirium and early cognitive dysfunction compared with sevoflurane-based general anesthesia