The Effect of Dexmedetomidine to Cognition of Geriatrics in Prolonged Surgery

Study Overview
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Brief Summary
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The incidence of postoperative cognitive dysfunction (POCD) is high and POCD affect the life quality and the prognosis of patients. Geriatrics is the independent risk factor of POCD, and POCD is also correlated with many other factors such as type of surgery, the duration of anesthesia and the anesthesia drugs used et al. So, the prevention and treatment of POCD in geriatrics is important. Dexmedetomidine is found to have the effect of neuro-protection, but it is controversy whether Dexmedetomidine has the effect of neuro-protection in geriatrics, especially the prolonged surgery. The purpose of this study is to explore the effect of Dexmedetomidine to the cognitive function at prolonged surgery in geriatrics in geriatrics.

Official Title
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The Effect of Dexmedetomidine to Cognition of Geriatrics in Prolonged Surgery,A Randomized Controlled Study

Conditions
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Cognitive Ability, General, Brain Injury

Intervention / Treatment
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* Drug: Induction of anesthesia
* Procedure: Intubation
* Drug: Sevoflurane, remifentanil ,vecuronium
* Drug: Dexmedetomidine
* Drug: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Written informed consent Scheduled for elective abdominal surgery Age≥65 yrs Weight is within the range of ±20% of standard weight [standard weight=Height(cm)-80)×70﹪ for male and(Height(cm)-70)×60﹪] for female American society of anesthesia classification I III Expected time of surgery is more than 4 hours - Exclusion Criteria: Systolic blood pressure≥180 mm Hg or <90 mm Hg，diastolic blood pressure≥110 mm Hg or < 60 mm Hg； Serious cardiac,liver,kidney,lung, endocrine disease or sepsis. Allergy to trial drug or other contraindication； Difficult airway occurred before,or difficult airway possibly occurred and difficult to extubation History of mental illness and cerebral vascular disease History of unstable angina or myocardial infarction Education level<7 yrs Factors existed that affect cognition assessment such as language, visual sense,auditory sense disorders. Abuse of narcotic analgesia or suspected; Neuromuscular diseases; Mentally unstable or has a mental illness; Pregnant or breast-feeding women; Attended other trial past 30 days; -

Ages Eligible for Study
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Minimum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Dexmedetomidine<br>Dexmedetomidine is given at 0.5μg/kg/h by continuous infusion and is stopped to given 30 minutes before the surgery is over. | Drug: Induction of anesthesia<br>* Midazolam 0.05 mg/kg、Propofol 1.0 mg/kg、Sufentanyl 3μg/kg、Victracurium 0.1 mg/kg sequential intravenous injection<br>Procedure: Intubation<br>* After muscle relaxed and loss of eyelash reflex of the patients, intubation is done,then mechanical ventilation is performed, and maintain the PETCO2于35 40 mmHg，pulse oxygen saturation is more than 95%.<br>Drug: Sevoflurane, remifentanil ,vecuronium<br>* Sevoflurane（1%-2%）is inspirated, and remifentanil 0.1-0.5μg/kg//min is continuously pumped,vecuronium 0.03 mg/kg is injected intermittently.<br>Drug: Dexmedetomidine<br>* Dexmedetomidine is given at 0.5μg/kg/h by continuous infusion and is stopped to given 30 minutes before the surgery is over.<br>|
| Sham Comparator: Normal saline<br>Normal saline is given at 0.5μg/kg/h by continuous infusion and is stopped to given 30 minutes before the surgery is over. | Drug: Induction of anesthesia<br>* Midazolam 0.05 mg/kg、Propofol 1.0 mg/kg、Sufentanyl 3μg/kg、Victracurium 0.1 mg/kg sequential intravenous injection<br>Procedure: Intubation<br>* After muscle relaxed and loss of eyelash reflex of the patients, intubation is done,then mechanical ventilation is performed, and maintain the PETCO2于35 40 mmHg，pulse oxygen saturation is more than 95%.<br>Drug: Sevoflurane, remifentanil ,vecuronium<br>* Sevoflurane（1%-2%）is inspirated, and remifentanil 0.1-0.5μg/kg//min is continuously pumped,vecuronium 0.03 mg/kg is injected intermittently.<br>Drug: Placebo<br>* Normal saline is given at 0.5μg/kg/h by continuous infusion and is stopped to given 30 minutes before the surgery is over.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change from baseline in cognitive function at 7 days | Modified Newman scale to assess the cognitive function, including five tests. The quiet environment, enough daylight, no disturb is needed when the modified Newman scale is done. All the five tests are finished within 30 min. all the score of each test of all the patients assessed before the surgery is calculated, then get the standard variation, the score of each subject of each test is compared with the standard deviation, if one or more stand deviation decrease, then the cognitive function is considered as deterioration . When 2 or more of the tests is considered as deterioration, then the patients is diagnosed as Post Operation Cognitive Dysfunction (POCD). | Baseline, the 7th day after the surgery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Brain injury assessment | 2 ml blood sample is collected at 8 time points including before surgery,the right moment,2 hr and 4 hr after the induction, the right moment,12,24 and 48 hours after the surgery. The serum level of C-reaction protein(CRP),tumor necrosis factor(TNF-α)、interleukin-6（IL-6）,interleukin-10（IL-10) is tested using immunohistochemical double antibody sandwich enzyme-linked immunosorbent assay (ELISA) | From entering the operating room to 48 hours after the surgery | 
| Inflammatory responsive assessment | 2 ml blood sample is collected at 8 time points including before surgery,the right moment,2 hr and 4 hr after the induction, the right moment,12,24 and 48 hours after the surgery. The concentration of protein S100B（S100B）and neuron specific enolase (NSE）in serum is tested using immunohistochemical double antibody sandwich enzyme-linked immunosorbent assay (ELISA). | From entering the operating room to 48 hours after the surgery | 
| Heart rate | Heart rate are monitored every 15 min from the induction of anesthesia to the right moment of extubation. | From the induction of anesthesia to the right moment of extubation, up to 1 day. | 
| Depth of anesthesia | Bispectral index(BIS) monitor are performed every 15 min from the induction of anesthesia to the right moment of extubation. | From the induction of anesthesia to the right moment of extubation, up to 1 day. | 
| Recovery of anesthesia | Time of anesthetic ceased,time of call to open eyes,time to extubation, time to leave the PACU are recorded. | From the induction of anesthesia to the right moment of extubation, up to 1 day. | 
| Central venous pressure(CVP) | Central venous pressure(CVP) are monitored every 15 min from the induction of anesthesia to the right moment of extubation. | From the induction of anesthesia to the right moment of extubation, up to 1 day. | 
| Blood pressure | systolic blood pressure, Diastolic blood pressure are monitored every 15 min from the induction of anesthesia to the right moment of extubation. | From the induction of anesthesia to the right moment of extubation, up to 1 day. | 
| Respiration rate | Respiration rate are monitored every 15 min from the induction of anesthesia to the right moment of extubation. | From the induction of anesthesia to the right moment of extubation, up to 1 day. | 
| Pulse blood oxygen saturation | Pulse blood oxygen saturation are monitored every 15 min from the induction of anesthesia to the right moment of extubation. | From the induction of anesthesia to the right moment of extubation, up to 1 day. | 
| Number of Participants with Serious and Non-Serious Adverse Events |  | Up to 7 days |