Norepinephrine and Phenylephrine, Which Better for Elderly?

Study Overview
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Brief Summary
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this is a prospective, double-blinded and single-center study. this study is based on the Stroke volume variation fluid guided therapy, to compare the effects of norepinephrine and phenylephrine in treating perioperative hypotension, and to find the safest and most effective vasopressor for elderly.

Official Title
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Comparison of the Effects of Norepinephrine and Phenylephrine on Tissue Oxygenation and Hemodynamic Stability During an Stroke Volume Variations(SVV) Fluid Guided Therapy in Elderly Undergoing Major Abdominal Surgery

Conditions
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Hypotension

Intervention / Treatment
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* Drug: norepinephrine
* Drug: Phenylephrine


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: radical resection of colorectal or gastric cancers, age over 65 years old, surgical time longer than 2hours, the American Society of Anesthesiologists(ASA) classification of II or III Exclusion Criteria: history of severe cardiovascular diseases, history of severe liver and kidney diseases, evidence of arrhythmia on EKG, use of positive end-expiratory pressure (PEEP) during mechanical ventilation; conditions with relative contraindication for arterial catheterization

Ages Eligible for Study
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Minimum Age: 60 Years
Maximum Age: 95 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: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: norepinephrine<br>Blood pressure is generally maintained at value not less than 80% of baseline during intraoperative period. If the blood pressure is within normal range and SVV is less than 9, patient will be given a continuous infusion of crystalloid solution. However, when blood pressure drops and SVV is greater than 13, a bolus of 200mL colloid will then be quickly administered. If the blood pressure doesn't recover back to normal range within 5 minutes after bolus, norepinephrine will be given through the central venous catheter. If SVV is between 9 and 13, a bolus of crystalloid at 8mL/kg/h will be administered | Drug: norepinephrine<br>* patient who was received the treatment of norepinephrine<br>* Other names: vasopressor;|
| Experimental: phenylephrine<br>Blood pressure is generally maintained at value not less than 80% of baseline during intraoperative period. If the blood pressure is within normal range and SVV is less than 9, patient will be given a continuous infusion of crystalloid solution. However, when blood pressure drops and SVV is greater than 13, a bolus of 200mL colloid will then be quickly administered. If the blood pressure doesn't recover back to normal range within 5 minutes after bolus, phenylephrine will be given through the central venous catheter. If SVV is between 9 and 13, a bolus of crystalloid at 8mL/kg/h will be administered. | Drug: Phenylephrine<br>* patient who was received the treatment of phenylephrine<br>* Other names: vasopressor;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| hemodynamics- (CO)cardiac output | (CO)cardiac output in Litres per minute. the indicator reflect the patients hemodynamic, which measured by the FloTrac/Vigileo 3.0 | change from patient enters the operating room to end of operation, assessed up to the whole operation | 
| Tissue perfusion and oxygenation-(DO2) Oxygen delivery; | Blood samples from the radial artery and internal jugular vein were taken at the same time in three time points respectively to measure arterial and venous blood gas, and Measured tissue oxygenation according to Fick equation:DO2(ml/min/m2)=CaO2×10×CI, Arterial oxygen content (CaO2)=Arterial hemoglobin concentration(Hba)×1.36×arterial oxygen saturation(SaO2) + 0.0031×arterial oxygen pressure (PaO2) ; | change from beginning of operation to end of operation, assessed up to the whole operation | 
| Tissue perfusion and oxygenation-(VO2)Oxygen consumption; | Blood samples from the radial artery and internal jugular vein were taken at the same time in three time points respectively to measure arterial and venous blood gas, and Measured tissue oxygenation according to Fick equation:VO2(ml/min/m2)= (CaO2-CcvO2)×CI×10, Intravenous oxygen content (CcvO2)= Intravenous hemoglobin concentration (Hbv)×1.36×Venous oxygen saturation (ScvO2) + 0.0031×venous oxygen pressure (PcvO2); | change from beginning of operation to end of operation, assessed up to the whole operation | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Goal-directed Fluid Therapy, norepinephrine, phenylephrine, elderly