Effects of Dexmedetomidine on Cardiac Electrophysiology in Patients Under General Anesthesia During Perioperative Period

Study Overview
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Brief Summary
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Perioperative stress may increase the incidence of adverse events in the cardiovascular system and lead to poor prognosis. Dexmedetomidine is a highly selective α2 adrenergic receptor agonist, which can inhibit stress response and reduce hemodynamic fluctuations. In different usage plans, dexmedetomidine can have different effects on hemodynamics, myocardial electrical activity, cardiac function. The main purpose was to observe its effects on myocardial electrophysiology and cardiac function during perioperative period. The secondary purpose was to explore the optimal dose of dexmedetomidine that has the least adverse effects on perioperative electrocardia action and cardiac function

Official Title
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Effects of Dexmedetomidine on Cardiac Electrophysiology in Patients Under General Anesthesia During Perioperative Period

Conditions
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Dexmedetomidine, General Anesthesia, Cardiac Electrophysiology, Cardiac Function

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


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Ages ranged from 18 to 65 ASA I II patients undergoing elective general anesthesia the surgery time for 1 3 h Exclusion Criteria: Preoperative ECG abnormalities, including QTc ≥440 ms (male), 460ms (female) abnormal cardiac conduction, prolonged QT syndrome heart disease history, such as pacemaker implantation, unstable angina, congestive heart failure, Heart valve disease antiarrhythmic drugs (β-receptor blockers, calcium channel blockers, tricyclic antidepressants, etc.) that can prolong the QT interval taken within one week before surgery coronary heart disease, non-sinus Heart rhythm, bradycardia, tachycardia, other arrhythmia, etc intraoperative HR≤45 beats/min and need drugs to increase heart rate previous allergy to dexmedetomidine preoperative electrolyte abnormalities emergency surgery, neurological or mental disorders , Liver and kidney dysfunction patients who use analgesic pumps after surgery refusal of patients

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

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: Loading dose with 0.5 μg/kg, maintenance dose with 0.5 μg/kg<br>10 min before induction of anesthesia,the loading dose of dexmedetomidine is 0.5 μg/kg, and completed in 10 minutes. The maintenance dose is 0.5 μg/kg per hour during the operation until 0.5 h before the operation finished. | Drug: Dexmedetomidine<br>* The loading dose with 0.5 μg/kg, maintenance dose with 0.5 μg/kg of Dexmedetomidine is used to observe the effect on the electrophysiology of the patients' hearts<br>|
| Experimental: Loading dose with 1 μg/kg, maintenance dose with 0.5 μg/kg<br>10 min before induction of anesthesia,the loading dose of dexmedetomidine is 1 μg/kg, and completed in 10 minutes. The maintenance dose is 0.5 μg/kg per hour during the operation until 0.5 h before the surgery finished. | Drug: Dexmedetomidine<br>* The loading dose with 1 μg/kg, maintenance dose with 0.5 μg/kg of Dexmedetomidine is used to observe the effect on the electrophysiology of the patients' hearts<br>|
| Experimental: Loading dose with 1 μg/kg, maintenance dose with 1 μg/kg<br>10 min before induction of anesthesia,the loading dose of dexmedetomidine is 1 μg/kg, and completed in 10 minutes. The maintenance dose is 1 μg/kg per hour during the operation until 0.5 h before the surgery finished. | Drug: Dexmedetomidine<br>* The loading dose with 1 μg/kg, maintenance dose with 1 μg/kg of Dexmedetomidine is used to observe the effect on the electrophysiology of the patients' hearts<br>|
| Placebo Comparator: Normal saline<br> | Drug: Normal saline<br>* Normal saline is used to observe the effect on the electrophysiology of the patients' hearts<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The length of PR,QRS,QTc,QT and Tp-e intervals and the level of iCEB | All the outcomes above should be measured at the time preparing to pump a loading dose,the time after the loading dose finished,at the end of surgery,1h after the surgery finished,24 h after the surgery finished,48 h after the surgery finished,72 h after the surgery finished,1 month after the surgery finished | during surgery to 1 month after the surgery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The level of Na+,iCa2+ | All the outcomes above should be measured at the time preparing to pump a loading dose,the time after the loading dose finished,1h after the beginning of the surgery,the end of surgery,1h after the surgery finished | perioperative | 
| The level of cardiac circulation efficiency | All the outcomes above should be measured at the time preparing to pump a loading dose,the time after the loading dose finished,1h after the beginning of the surgery,the end of surgery,1h after the surgery finished | Perioperative | 
| The level of maximum pressure gradient | the time preparing to pump a loading dose,the time after the loading dose finished,the beginning of surgery, 30min after the beginning of surgery,1h after the beginning of the surgery,the end of surgery,1h after the surgery finished | Perioperative | 
| The level of heart rate | the time preparing to pump a loading dose,the time after the loading dose finished,the beginning of surgery, 30min after the beginning of surgery,1h after the beginning of the surgery,the end of surgery,1h after the surgery finished | Perioperative | 
| The level of mean arterial blood pressure |  | Perioperative | 
| The level of systemic vascular resistance | the time preparing to pump a loading dose,the time after the loading dose finished,the beginning of surgery, 30min after the beginning of surgery,1h after the beginning of the surgery,the end of surgery,1h after the surgery finished | Perioperative | 
| The time of eyes opening from surgery ending,the whole surgery,anesthesia |  | intraoperative | 
| The dosage of propofol and remifentanil |  | intraoperative | 
| Total fluid intake from entering the operating room to exiting the PACU |  | Perioperative |