Objective To investigate the risk factors for postoperative delirium in patients after vascular free flap reconstruction performed under general anesthesia.Methods Two hundred and sixteen ASA Ⅰ-Ⅲ patients aged 18-80 yr undergoing vascular free flap reconstruction surgery were enrolled in this study.Patient characteristics before and during operation were recorded.The patients were followed up for 5 days after operation.Their level of consciousness,severity of pain and sleep quality were evaluated daily.The patients were divided into 2 groups according to the occurrence of delirium during the 5 days after operation:delirium group and non-delirium group.The method of CAM-ICU was reed in the diagnosis of postoperative delirium.Multivariate logistic regression was used to analyze the risk factors for postoperative delirium.Results logistic regression analysis showed that old age,history of alcohol abuse and sleep diacrder after operation were risk factors for delirium developed after free flap surgery.Conclusion Old age,history of alcohol abuse and sleep disorder after operation were the risk factors for postoperative delirium in patients after vascular free flap reconstruction performed under general anesthesia.