Effects of Dexmedetomidine on Postoperative Cognitive Dysfunction During One-lung Ventilation in Elder Patients

Study Overview
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Brief Summary
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This study is to explore the effects of dexmedetomidine on postoperative cognitive dysfunction during one-lung ventilation in elder patients.

Official Title
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Effects of Dexmedetomidine on Postoperative Cognitive Dysfunction During One-lung Ventilation in Elder Patients -a Single-center, Randomized ,Double-blinded and Controlled Trial

Conditions
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Postoperative Confusion

Intervention / Treatment
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* Drug: Induction of anesthesia,midazolam ,sufentanil,etomidate and rocuronium
* Drug: Dexmedetomidine
* Drug: Normal saline
* Drug: Maintenance of anesthesia , propofol, remifentanil,vecuronium


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Written informed consent. Ongoing one-lung ventilation surgery. American Society of Anesthesiologists class I to III. Aged between 55 and 75 years old. Body Mass Index between 18 and 25 kg/m2. Exclusion Criteria: Systolic blood pressure more than 180 mmHg or lower than 90 mmHg,diastolic blood pressure more than 110 mmHg or lower than 60 mmHg. Serious heart,liver,kidney, pulmonary, and endocrine disease or serious infection. Suspected or confirmed difficult airway. History of abnormal anesthesia. Suspected of malignant hyperthermia. Use of sedative and antidepressant drug or serious alcoholism Mini-mental State Examination less than 17. Highest academic degree below grade 6 in primary schools Patients inability to exchange with serious visual and hearing impairment or mental disability. History of shock. Carotid artery stenosis and central nervous system disease such as stroke, epilepsy. Allergic to investigational products or with other contraindication. Participated in other study within 30 days .

Ages Eligible for Study
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Minimum Age: 55 Years
Maximum Age: 75 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: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Placebo Comparator: Normal saline<br>Continuous pump infusion of normal saline with identical volume, compared with the low dose and high dose group,until the end of surgery | Drug: Induction of anesthesia,midazolam ,sufentanil,etomidate and rocuronium<br>* Anesthesia induction:midazolam (0.03 0.05 mg/kg), sufentanil(0. 5 0.8 μg/kg), etomidate ( 0.2 0.6mg/kg) and rocuronium(0.6mg/kg)<br>Drug: Normal saline<br>* Continuous pump infusion normal saline with identical volume of dexmedetomidine.<br>Drug: Maintenance of anesthesia , propofol, remifentanil,vecuronium<br>* Continuous infusion of propofol （3 6 mg/kg/h）, remifentanil （0.05 0.3 μg/kg/min）is required to maintain Entropy within 40 60,Mean Arterial Blood Pressure more than 20% of baseline level , Oxygen Saturation more than 90% , airway pressure less than 40 cm H2O, intermittent injection vecuronium （0.05 0.1mg/kg） as needed to maintain muscle relaxation.<br>|
| Experimental: High dose group, dexmedetomidine<br>Continuous pump infusion dexmedetomidine at 1μg/kg for 15 minutes before anesthesia induction ,then continuous pump infusion dexmedetomidine at 0.4μg/kg/h until the end of surgery | Drug: Induction of anesthesia,midazolam ,sufentanil,etomidate and rocuronium<br>* Anesthesia induction:midazolam (0.03 0.05 mg/kg), sufentanil(0. 5 0.8 μg/kg), etomidate ( 0.2 0.6mg/kg) and rocuronium(0.6mg/kg)<br>Drug: Dexmedetomidine<br>* Continuous pump infusion dexmedetomidine at 0.5μg/kg （low dose group）or 1μg/kg （high dose group）for 15 minutes before anesthesia induction，then followed by a continuous pump infusion at 0.2 μg/kg/h（low dose group）or 0.4μg/kg/h（high dose group） until the end of surgery.<br>Drug: Maintenance of anesthesia , propofol, remifentanil,vecuronium<br>* Continuous infusion of propofol （3 6 mg/kg/h）, remifentanil （0.05 0.3 μg/kg/min）is required to maintain Entropy within 40 60,Mean Arterial Blood Pressure more than 20% of baseline level , Oxygen Saturation more than 90% , airway pressure less than 40 cm H2O, intermittent injection vecuronium （0.05 0.1mg/kg） as needed to maintain muscle relaxation.<br>|
| Experimental: Low dose group, dexmedetomidine<br>Continuous pump infusion dexmedetomidine at 0.5μg/kg for 15 minutes before anesthesia induction ,then continuous pump infusion dexmedetomidine at 0.2μg/kg/h until the end of surgery | Drug: Induction of anesthesia,midazolam ,sufentanil,etomidate and rocuronium<br>* Anesthesia induction:midazolam (0.03 0.05 mg/kg), sufentanil(0. 5 0.8 μg/kg), etomidate ( 0.2 0.6mg/kg) and rocuronium(0.6mg/kg)<br>Drug: Dexmedetomidine<br>* Continuous pump infusion dexmedetomidine at 0.5μg/kg （low dose group）or 1μg/kg （high dose group）for 15 minutes before anesthesia induction，then followed by a continuous pump infusion at 0.2 μg/kg/h（low dose group）or 0.4μg/kg/h（high dose group） until the end of surgery.<br>Drug: Maintenance of anesthesia , propofol, remifentanil,vecuronium<br>* Continuous infusion of propofol （3 6 mg/kg/h）, remifentanil （0.05 0.3 μg/kg/min）is required to maintain Entropy within 40 60,Mean Arterial Blood Pressure more than 20% of baseline level , Oxygen Saturation more than 90% , airway pressure less than 40 cm H2O, intermittent injection vecuronium （0.05 0.1mg/kg） as needed to maintain muscle relaxation.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The change in memory | The change in memory will be evaluated by Controlled Oral Word Association Test ,Semantic Fluency test | one day before operation, first day after operation | 
| Cognitive function | Cognitive function will be evaluated by Mini-mentalStateExamination,Digit-Symbol Substitution Test ,Trail Making Test | one day before operation, first day after operation | 
| Postoperative anxiety | Self-evaluation of Depression Symptoms form,Self-Rating Anxiety Scale,Visual analog scales | one day before operation, first day after operation | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Heart rate |  | At the moment of entering operating room ,the moment of intubation，prior to one lung ventilation,10 minutes,30 minutes afer one lung ventilation,the end of operation and the moment of leaving the operating room | 
| Bleeding volume |  | At the beginning of operation,at the end of operation,up to 24 hours | 
| Total volume of fluid |  | At the beginning of operation,at the end of operation,up to 24 hours | 
| Duration of one lung ventilation |  | At the beginning of one lung ventilation,at the end of one lung ventilation,an expected average of 3 hours | 
| The total dose of anaesthetic drugs |  | At the beginning of surgery,at the end of surgery,up to 24 hours | 
| The total dose of analgesic drugs |  | During perioperative period,up to 7 days | 
| Blood pressure |  | At the moment of entering operating room ,the moment of intubation，prior to one lung ventilation,10 minutes,30 minutes afer one lung ventilation,the end of operation and the moment of leaving the operating room | 
| Oxygen saturation |  | At the moment of entering operating room ,the moment of intubation，prior to one lung ventilation,10 minutes,30 minutes afer one lung ventilation,the end of operation and the moment of leaving the operating room | 
| End-tidal carbon dioxide |  | At the moment of entering operating room ,the moment of intubation，prior to one lung ventilation,10 minutes,30 minutes afer one lung ventilation,the end of operation and the moment of leaving the operating room | 
| Operation duration |  | At the beginning of surgery,at the end of surgery,up to 24 hours |