Effect of Dexmedetomidine Preconditioning on Myocardial Ischemia-reperfusion Injury in Patients Undergoing Open Heart Surgery With Cardiopulmonary Bypass

Study Overview
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Brief Summary
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About 200000 cardiac operations are performed in China every year. Cardiopulmonary bypass is the basic strategy of open-heart surgery, which may lead to myocardial ischemia-reperfusion injury and low cardiac output syndrome. It will inevitably affect the patient's postoperative recovery. A number of studies have shown that dexmedetomidine, as an auxiliary sedative, has the effects of inhibiting stress response, antiarrhythmia and cardiac protection.Dexmedetomidine has been widely used in anesthesia in cardiac surgery. However, at present, few clinical studies pay attention to its mechanism. In this study, dexmedetomidine will be used in cardiac surgery with cardiopulmonary bypass to explore the mechanism of cardiac ischemia-reperfusion injury and the protective effect of dexmedetomidine.

Official Title
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Effect of Dexmedetomidine Preconditioning on Myocardial Ischemia-reperfusion : a Randomized, Double-blind Clinical Trial

Conditions
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Ischemia-Reperfusion Injury

Intervention / Treatment
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* Drug: dexmedetomidine
* Drug: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Aged 18-70 years American Society of Anesthesiologists(ASA) physical status of I-Ⅳ BMI: 18.5-28 kg/m2 Type of operation: elective open-heart surgery with cardiopulmonary bypass The patient and/or family members have signed the informed consent. Exclusion Criteria: Preoperative diagnosis of heart failure 、gradeⅡ-Ⅲ heart block and diabetes LEVF<40% Severe coagulation dysfunction Severe heart, lung, liver and kidney insufficiency Used to have immunosuppressive therapies such as radiotherapy, chemotherapy and glucocorticoid, or have immune system diseases Perioperative allogeneic blood transfusion

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 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: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Group D<br>The participant will be infused with dexmedetomidine during anesthesia to protect the myocardium. | Drug: dexmedetomidine<br>* The participant will pump dexmedetomidine at the rate of 1μg/(Kg·h) for 10 minutes at the beginning of anesthesia induction, and then maintain the pump at a rate of 0.5μg/(Kg·h) during the operation.<br>|
| Placebo Comparator: Group R<br>The participant will use saline of the same volume as dexmedetomidine as a placebo during anesthesia. | Drug: Placebo<br>* The participant will pump saline without dexmedetomidine at the same speed as group D.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| troponin T level | the level of troponin in the participant's serum | before operation | 
| troponin T level | the level of troponin in the participant's serum | the end of operation | 
| troponin T level | the level of troponin in the participant's serum | when the participant returned to the ward after the operation | 
| troponin T level | the level of troponin in the participant's serum | 24 hours after operation | 
| troponin T level | the level of troponin in the participant's serum | 72 hours after operation | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| AQP4、iNOS andTNF-α level | the level of AQP4、iNOS andTNF-α in the participant's serum | before operation | 
| AQP4、iNOS andTNF-α level | the level of AQP4、iNOS andTNF-α in the participant's serum | when blocking the ascending aorta | 
| AQP4、iNOS andTNF-α level | the level of AQP4、iNOS andTNF-α in the participant's serum | when developing the ascending aorta | 
| AQP4、iNOS andTNF-α level | the level of AQP4、iNOS andTNF-α in the participant's serum | when cardiopulmonary bypass is stopped | 
| AQP4、iNOS andTNF-α level | the level of AQP4、iNOS andTNF-α in the participant's serum | the end of the operation |