Dexmedetomidine, Elderly, Knee Arthroplasty, Long-term Outcome, Nerve Block, Postoperative Delirium
Conditions
Keywords
Elderly, Knee Arthroplasty, Nerve Block, Dexmedetomidine, Postoperative Delirium, Long-term Outcome
Brief summary
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.
Detailed description
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.
Interventions
DRUGDexmedetomidine
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).
DRUGPlacebo
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.
Sponsors
Beijing Jishuitan Hospital
Peking University First Hospital
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
65 Years to 90 Years
Healthy volunteers
No
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.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Incidence of delirium during the first 3 days after surgery | The first 3 days after surgery | Incidence of delirium during the first 3 days after surgery |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Quality of life at 30 days after surgery | 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. |
| Incidence of new-onset diseases within 3 years after surgery | Up to 3 years after surgery | Incidence of new-onset diseases within 3 years after surgery |
| Quality of life at the end of the 1st, 2nd, and 3rd years after surgery: SF-12 | At the end of the 1st, 2nd, and 3rd years after surgery | 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. |
| Cognitive function at the end of the 1st, 2nd, and 3rd years after surgery | 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. |
| Daily prevalence of delirium during postoperative days 1-3 | The first 3 days after surgery | Daily prevalence of delirium during postoperative days 1-3 |
| Length of stay in hospital after surgery | Up to 30 days after surgery | Length of stay in hospital after surgery |
| Incidence of non-delirium complications within 30 days after surgery | Up to 30 days after surgery | Incidence of non-delirium complications within 30 days after surgery |
| All-cause 30-day mortality | At 30 days after surgery | All-cause 30-day mortality |
| Cognitive function at 30 days after surgery | 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. |
| Overall survival within 3 years after surgery | Up to 3 years after surgery | Overall survival within 3 years after surgery |
| Survival rates at the end of the 1st，2nd, and 3rd years after surgery | At the end of the 1st, 2nd, and 3rd years after surgery | Survival rates at the end of the 1st，2nd, and 3rd years after surgery |
Other
| Measure | Time frame | Description |
|---|---|---|
| Sleep quality during postoperative days 1-3 | The first 3 days after surgery | Sleep quality during postoperative days 1-3 is assessed with the Verran and Snyder-Halpern (VSH) Sleep Scale, an 8-item questionnaire that evaluate multiple aspects of sleep during the previous night. Each item is scored in a range from 0 (very bad) to 10 (very good), and the total VSH score is determined by the summation of these scores (range 0-80). A higher total VSH score indicates a better quality of sleep. |
| Sedation level during postoperative days 1-3 | The first 3 days after surgery | Sedation level during postoperative days 1-3 is assessed with the Richmond Agitation-Sedation Scale (RASS), of which the range is as follows: +4 (combative), +3 (very agitated), +2 (agitated), +1 (restless), 0 (alert and clam), -1 (drowsy), -2 (light sedation), -3 (moderate sedation), -4 (deep sedation), and -5 (unarousable). |
| Pain severity during postoperative days 1-3: NRS | The first 3 days after surgery | Pain severity during postoperative days 1-3 is assessed with the Numeric Rating Scale (NRS), an 11-point pain scale where 0=no pain and 10=the most severe pain. |
Outcome results
None listed