Transcutaneous Electrical Stimulation of the Vagus Nerve

The Effect of Transcutaneous Electrical Stimulation of the Vagus Nerve on Reduction of Postoperative Cognitive Dysfunction in Elderly Patients After Hip or Knee Arthroplasty

This study evaluate the cognitive functions of patient after hip or kneel replacement.Half of the patient will receive transcutaneous vagus nerve electrical stimulation during the surgery while the other half will get placebo therapy

Inclusion Criteria:

• over 65 years old
• ability to communication
• hip or kneel replacement
• willing to participate in the study
• ASA I-II

Exclusion Criteria:

• with cerebral disorders or disease
• cognitive impairment before surgery
• with mental disease
• unable to communication
• severe eyes or ears impairment
• surgery performed in the past 30 days
• Bradycardia，II°AVB，III°AVB，severe heart, liver and kidney dysfunction
• severe skin disease
• refuse to enter the study