Participants
atrioventricular block, alcoholism, gastrointestinal or lung tumors, drug abuse, visual or hearing impairment, Cancer
ATRIOVENTRICULAR BLOCK, SINUS SICK SYNDROME, DISEASES, CANCER
The inclusion criteria were patients aged 60 years or older who underwent elective surgery for gastrointestinal or lung tumors in Zhejiang Cancer Hospital. The exclusion criteria were: (1) patients with a clear preoperative history of nervous system and mental system diseases or long-term use of sedatives or antidepressants; (2) history of alcoholism, drug abuse or drug dependence; (3) have a history of brain surgery or injury; (4) serious visual or hearing impairment; (5) patients who failed to complete the cognitive function test or refused to participate in the study; (6) sick sinus syndrome, second-degree or greater atrioventricular block or other contraindications for use of α