Dexmedetomidine Combined With Ropivacaine for Postoperative Continuous Femoral Nerve Block

Phase 4TerminatedNCT03629483

Peking University First Hospital3 enrolled

Overview

Delirium is common in the elderly after orthopedic surgery and is associated with worse outcomes. Continuous femoral nerve block is frequently used for postoperative analgesia after total knee arthoplasty. The investigators hypothesize that dexmedetomidine, when combined with ropivacaine for continuous femoral nerve block, can reduce the incidence of delirium and improve the long-term outcome in elderly patients after total knee arthroplasty.

A growing number of elderly patients undergo total knee arthroplasty. Delirium is a common complication in these patients after surgery and is associated with worse outcomes, including prolonged hospital stay, poor functional recovery, decreased cognitive function, increased health care costs, and elevated mortality rate. Dexmedetomidine has been shown to prolong the duration of nerve block without neurotoxicity and improve postoperative sleep quality. The investigators hypothesize that dexmedetomidine, when combined with ropivacaine for continuous femoral nerve block, can reduce the incidence of delirium and improve the long-term outcome in elderly patients after total knee arthroplasty.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

PREVENTION

Masking

QUADRUPLE

Enrollment

Conditions

Elderly Knee Arthroplasty

Interventions

DexmedetomidineDRUG

Patients in this group receive continuous femoral nerve block analgesia for 48 hours after surgery. The formula is a mixture of 0.2% ropivacaine 250ml and 3.75 ug/kg dexmedetomidine. The analgesic pump is set to administer a continuous infusion at a rate of 5 ml/h (equivalent to a dexmedetomidine infusion at a rate of 0.075 ug/kg/h).

PlaceboDRUG

Patients in this group receive continuous femoral nerve block analgesia for 48 hours after surgery. The formula is a mixture of 0.2% ropivacaine 250 ml and placebo. The analgesic pump is set to administer a continuous infusion at a rate of 5 ml/h.

Eligibility

Sex: ALLMin age: 65 YearsMax age: 90 Years

Medical Language ↔ Plain English

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.

Outcomes

Primary Outcomes

Incidence of delirium during the first 3 days after surgery

Time frame: The first 3 days after surgery

Secondary Outcomes

Daily prevalence of delirium during postoperative days 1-3

Time frame: The first 3 days after surgery

Length of stay in hospital after surgery

Time frame: Up to 30 days after surgery

Incidence of non-delirium complications within 30 days after surgery

Time frame: Up to 30 days after surgery

All-cause 30-day mortality

Time frame: At 30 days after surgery

Quality of life at 30 days after surgery

Quality of life at 30 days after surgery is assessed with the 12-items Short Form Health Survey (SF-12), a 12-item questionnaire that provides assessments of physical and mental health-related quality of life. The score ranges from 12 to 48, with higher score indicating better function.

Time frame: At 30 days after surgery

Cognitive function at 30 days after surgery

Cognitive function at 30 days after surgery is assessed with modified Telephone Interview for Cognitive Status (TICS-m), a 12-item questionnaire that provides an assessment of global cognitive function by verbal communication via telephone. The score ranges from 0 to 50, with higher score indicating better function.

Time frame: At 30 days after surgery

Overall survival within 3 years after surgery

Time frame: Up to 3 years after surgery

Survival rates at the end of the 1st，2nd, and 3rd years after surgery

Time frame: At the end of the 1st, 2nd, and 3rd years after surgery

Incidence of new-onset diseases within 3 years after surgery

Time frame: Up to 3 years after surgery

Quality of life at the end of the 1st, 2nd, and 3rd years after surgery: SF-12

Quality of life at the end of the 1st, 2nd, and 3rd years after surgery is assessed with the 12-items Short Form Health Survey (SF-12), a 12-item questionnaire that provides assessments of physical and mental health-related quality of life. The score ranges from 12 to 48, with higher score indicating better function.

Time frame: At the end of the 1st, 2nd, and 3rd years after surgery

Cognitive function at the end of the 1st, 2nd, and 3rd years after surgery

Cognitive function at the end of the 1st, 2nd, and 3rd years after surgery is assessed with modified Telephone Interview for Cognitive Status (TICS-m), a 12-item questionnaire that provides an assessment of global cognitive function by verbal communication via telephone. The score ranges from 0 to 50, with higher score indicating better function.

Time frame: At the end of the 1st, 2nd, and 3rd years after surgery