Effects of electroacupuncture on postoperative delirium in elderly patients after total knee arthroplasty: study protocol for a multi-centre, randomized, controlled trial

INTERVENTION: Electro Acupuncture:Electro acupuncture treatment on acupoints;Sham Electro Acupuncture:Sham electro acupuncture treatment on sham acupoints; CONDITION: Postoperative delirium PRIMARY OUTCOME: The prevalence of postoperative delirium; SECONDARY OUTCOME: Postoperative delirium severity and duration;The cumulative prevalence of postoperative cognitive dysfunction;The postoperative pain at rest and movement;Postoperative recovery quality;Sleep and disturbance;Postoperative cumulative opioid consumption;Time to mobilization;Time to gastrointestinal functional recovery;Postoperative anxiety and depression; INCLUSION CRITERIA: (i) Aged equal to or over 65 years; (ii) General anasthesia and ASA II‐?.