Comparison the Hemodynamics Effects Between Dexmedetomidine and Propofol in Major Abdominal Surgical Patients

Study Overview
=================
Brief Summary
-----------------
The alpha2 agonist dexmedetomidine is a new sedative agent combined with the analgesic qualities and lack of respiratory depression. Patients sedated with dexmedetomidine could be easily roused, these advances shows dexmedetomidine may be a effective and safe sedative agent. But some studies showed some adversely effects of dexmedetomidine on haemodynamics (such as bradycardia, hypotension), the investigators want to further research the effects of dexmedetomidine on haemodynamics, such as Cardiac Output (CO), Systemic Venous Resistance Index(SVRI), and so on. Propofol is widely used sedative agent in ICU, it also has adversely effects like bradycardia and hypotension, so the investigators want to compare the effect of dexmedetomidine with propofol on haemodynamics after major abdominal surgery. Expect to further research the mechanism of haemodynamics of dexmedetomidine.

Detailed Description
-----------------
When the patients can be roused, they will first receive analgesia with bolus of fentanyl 0.03mg, followed by a continuous infusion at a ﬁxed dose of 0.3μg/kg/h during study period. Then patients will be randomly divided into two groups (Dexmedetomidine and Propofol). All of them will receive hemodynamic monitoring through Vigileo(Edwards Lifesciences) and cardiogram monitor. The study will continue for 6-24 hours.

Official Title
-----------------
Comparison the Hemodynamics Effects Between Dexmedetomidine and Propofol in Major Abdominal Surgical Patients

Conditions
-----------------
Abdominal Tumor, Intestinal Obstruction, Cirrhosis, Intestinal Fistula, Aneurism

Intervention / Treatment
-----------------
* Drug: dexmedetomidine
* Drug: propofol


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Postoperative patients of major abdominal surgery Age ≧ 18 Exclusion Criteria: heart rate ≤ 50 bpm allergy with dexmedetomidine or propofol pregnancy

Ages Eligible for Study
-----------------
Minimum Age: 18 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| dexmedetomidine,hemodynamics,injection<br>Group 1:when the patient can be roused after major abdominal surgery ，we will inject dexmedetomidine at 1μg/kg in 10 minutes as a loading dose, followed by a continuous infusion at 0.3μg/kg/h for 6 to 24hours.then adjust the infusion dose to maintain the ramsay scale at 3-4 scores. | Drug: dexmedetomidine<br>* dexmedetomidine: IV (in the vein)at 1μg/kg in 10 minutes as a loading dose, followed by a continuous infusion at 0.3μg/kg/h.then adjust the infusion dose to maintain the ramsay scale at 3-4 scores.<br>|
| propofol,hemodynamics,injection<br>Group 2 :when the patient can be roused after major abdominal surgery ，we will inject propofol at 0.5mg/kg as a loading dose, followed by a continuous infusion at 0.5mg/kg.h for 6 to 24hours.then adjust the infusion dose to maintain the ramsay scale at 3-4 scores | Drug: propofol<br>* propofol: IV (in the vein)at 0.5mg/kg as a loading dose, followed by a continuous infusion at 0.5mg/kg/h.then adjust the infusion dose to maintain the ramsay scale at 3-4 scores.<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Cardiac output |  | the study will start when the patient can be roused after major abdominal surgery and will continue for 6 to 24hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Stroke Volume |  | the study will start when the patient can be roused after major abdominal surgery and will continue for 6 to 24hours |