Effect of Es-ketamine on Postoperative Delirium Among Old Patients With Lobectomy

Inclusion Criteria: * 60 years old; There is no limit on the gender, ASA (American Society of Anesthesiologists )Ⅰ-Ⅲ Exclusion Criteria: * Emergency surgery, severe hepatic and renal dysfunction, shock or coma, psychiatric disease or central nervous system disorder or a history of long-term use of psychiatric medications, cognitive dysfunction, severe arrhythmia or bradycardia, ketamine allergy,drug abuse history and used other sedatives for nearly a week