Dexmedetomidine Combined With Ropivacaine for Postoperative Continuous Femoral Nerve Block
Elderly, Knee Arthroplasty, Nerve Block
About this trial
This is an interventional prevention trial for Elderly focused on measuring Elderly, Knee Arthroplasty, Nerve Block, Dexmedetomidine, Postoperative Delirium, Long-term Outcome
Eligibility Criteria
Inclusion Criteria:
- Elderly patients (≥ 65 years but < 90 years);
- Scheduled to undergo single total knee arthroplasty;
- Planned to receive continuous femoral nerve block for postoperative analgesia.
Exclusion Criteria:
- Refuse to participate in this study;
- Preoperative history of schizophrenia, epilepsy, Parkinsonism, or myasthenia gravis;
- Inability to communicate in the preoperative period because of coma, profound dementia or language barrier;
- Preoperative hemorrhagic disease or coagulopathy (platelet count, prothrombin time and/or activated partial thrombin time below the lower limit of normal);
- Preoperative obstructive sleep apnea (diagnosed as obstructive sleep apnea, or STOP-Bang score ≥3);
- Preoperative sick sinus syndrome, severe sinus bradycardia (< 50 beats per minute), or second-degree or above atrioventricular block without pacemaker;
- Severe hepatic dysfunction (Child-Pugh class C);
- Severe renal dysfunction (requirement of renal replacement therapy before surgery);
- ASA classification ≥ IV or unlikely to survive for more than 24 hours after surgery.
Sites / Locations
- Peking University First Hospital
- Beijing Jishuitan Hospital
Arms of the Study
Arm 1
Arm 2
Experimental
Placebo Comparator
Dexmedetomidine group
Control group
For patients in the dexmedetomidine group, postoperative analgesia is provided in the form of continuous femoral nerve block. The formula contains a mixture of 0.2% ropivacaine 250 ml and 3.75 ug/kg dexmedetomidine. The analgesic pump is set to administer a continuous infusion at a rate of 5 ml/h for 48 hours (equivalent to dexmedetomidine infusion at a rate of 0.075 ug/kg/h).
For patients in the control group, postoperative analgesia is provided in the form of continuous femoral nerve block. The formula contains a mixture of 0.2% ropivacaine 250 ml and placebo (normal saline). The analgesic pump is set to administer a continuous infusion at a rate of 5 ml/h for 48 hours.