The purpose of this study is the efficiency of es-ketamine on postoperative delirium among old patients with elective lobectomy

This study aimed to investigate the effect of IV es-ketamine vs saline on the incidence of postoperative delirium. It was hypothesized that IV es-ketamine would reduce the incidence of in-hospital delirium during cardiac surgery 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