Effects of Dexmedetomidine on Postoperative Cognitive Dysfunction During One-lung Ventilation in Elder Patients

Effects of Dexmedetomidine on Postoperative Cognitive Dysfunction During One-lung Ventilation in Elder Patients -a Single-center, Randomized ,Double-blinded and Controlled Trial

This study is to explore the effects of dexmedetomidine on postoperative cognitive dysfunction during one-lung ventilation in elder patients.

Inclusion Criteria:

• Written informed consent.
• Ongoing one-lung ventilation surgery.
• American Society of Anesthesiologists class I to III.
• Aged between 55 and 75 years old.
• Body Mass Index between 18 and 25 kg/m2.

Exclusion Criteria:

• Systolic blood pressure more than 180 mmHg or lower than 90 mmHg,diastolic blood pressure more than 110 mmHg or lower than 60 mmHg.
• Serious heart,liver,kidney, pulmonary, and endocrine disease or serious infection.
• Suspected or confirmed difficult airway.
• History of abnormal anesthesia.
• Suspected of malignant hyperthermia.
• Use of sedative and antidepressant drug or serious alcoholism
• Mini-mental State Examination less than 17.
• Highest academic degree below grade 6 in primary schools
• Patients inability to exchange with serious visual and hearing impairment or mental disability.
• History of shock.
• Carotid artery stenosis and central nervous system disease such as stroke, epilepsy.
• Allergic to investigational products or with other contraindication.
• Participated in other study within 30 days .