Anesthesia and Perioperative Neurocognitive Disorders in the Elderly Patients Undergoing Hip Fracture Surgery Platform Trial (ANDES Platform Trial)

The ANDES Platform Trial is a pragmatic, multicenter, adaptive randomized controlled platform trial in patients aged 65 years or older undergoing surgery for hip fracture. The trial evaluates whether enhanced anesthesia techniques reduce perioperative neurocognitive disorders compared with standard anesthesia care. The platform includes two randomization processes. In the first randomization, eligible participants are assigned to an active platform intervention-currently a preoperative regional nerve block or perioperative intravenous lidocaine infusion-or to a shared standard-anesthesia control. Participants for whom general anesthesia is planned may also enter a second, nested randomization and are assigned in a fixed 1:1 ratio to total intravenous anesthesia or volatile inhalational anesthesia, regardless of whether they participate in the first randomization. A non-surgical cognitive control cohort is included to characterize changes in cognitive test performance over time without exposure to surgery or study interventions. The Data Monitoring Committee reviews accumulating trial data and makes recommendations to the Trial Steering Committee, which determines whether platform interventions should continue, be modified, advance, or stop.