Effect of Intraoperative Dexmedetomidine on Lung Protection Following Thoracic Aorta Surgery With Hypothermic Circulatory Arrest: a Randomized Clinical Trial

Study Overview
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Brief Summary
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Dexmedetomidine has been known to protect the lung against inflammation and oxidative stress in diverse clinical settings. The investigators aimed to investigate the lung protective effect of dexmedetomidine in patients undergoing thoracic aortic surgery with hypothermic circulatory arrest, which is associated with systemic inflammatory response, and oxidative stress.

Detailed Description
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Patients will be divided into 2 groups; dexmedetomidine group and control group. Dexmedetomidine group will receive dexmedetomidine during and after thoracic artery surgery. And control group will receive the same amount of normal saline instead. Analyzing patients lung function and serum factors, which indicates the degree of systemic inflammatory responses and oxidative stress, The investigators will investigate the protective effect of dexmedetomidine on lung.

Official Title
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Effect of Intraoperative Dexmedetomidine on Lung Protection Following Thoracic Aorta Surgery With Hypothermic Circulatory Arrest: a Randomized Clinical Trial

Conditions
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Chronic Dissecting Aneurysm of Thoracic Aorta, Chronic Nontraumatic Dissection of Thoracic Aorta, Dissecting Aneurysm of the Thoracic Aorta

Intervention / Treatment
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* Drug: Dexmedetomidine
* Drug: normal saline


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients undergoing thoracic aorta surgery with hypothermic circulatory arrest, over 20-of age Exclusion Criteria: Unstable vital sign before surgery Severe pulmonary disease requiring consistent treatment Illiterate Pregnancy

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 98 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: Dexmedetomidine<br>1ug/kg IV loading over 20 minutes followed by 0.5ug/kg/hr IV infusion until 12hr of aortic cross clamp off | Drug: Dexmedetomidine<br>* 1ug/kg IV loading over 20 minutes followed by 0.5ug/kg/hr IV infusion until 12 hrs of aortic cross clamp off<br>* Other names: precedex;|
| Placebo Comparator: Normal saline<br>IV loading and infusion of same volume of normal saline after induction until 12hr of aortic cross clamp off | Drug: normal saline<br>* IV loading and infusion of same volume of normal saline after induction until 12 hrs of aortic cross clamp off<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes of lung oxygenation from baseline to 24 hr after reperfusion | Lung oxygenation will be assessed by arterial blood gas analysis | after induction of anesthesia / after reperfusion 1hr / after reperfusion 6hr / after reperfusion 12hr / after reperfusion 24hr | 
| Changes of lung compliance from baseline to 24 hr after reperfusion | Lung compliance will be displayed on the ventilator | after induction of anesthesia / after reperfusion 1hr / after reperfusion 6hr / after reperfusion 12hr / after reperfusion 24hr |