Ketamine Prevent POCD

Low Dose Ketamine Prevent the Postoperative Cognitive Dysfunction in Aged Patients Underwent Orthopaedic Surgery，a Randomized Control Double Blinded Multicenter Clinical Trail

Previous study demonstrated that neuroinflammation induced by surgery is the main cause of the postoperative cognitive dysfunction. As an agonist of NMDA receptor, ketamine is proved to be an anti-inflammation agent. In present study investigators hypothesized that low dose ketamine would prevent the cognition decline after orthopedic surgery in aged patients.

Inclusion Criteria:

• Elder than 60
• Easily communicated with Chinese
• Selected to kneel or hip replacement
• Agree to take part into this clinical trail

Exclusion Criteria:

• Existing cerebral disease， or have a history of neurological and psychiatric disease including AD, stroke and psychosis
• Existing cognitive impairment as evidenced by Mini-Mental State Examination scores below 24
• Several audition or vision disorder
• Preoperative systolic Blood pressure over 190mmHg or diastolic pressure >100mmHg
• Existing a history of hyperthyroidism
• Patient with glaucoma
• Unwillingness to comply with the protocol or procedures