Cardiac Output Changes During Hyperbaric and Isobaric Bupivacaine in Patients Undergoing Cesarean Section

Study Overview
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Brief Summary
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Spinal block leads to the reduction of systemic vascular resistance (SVR) which may effect the cardiac output. Ngan Kee et al. has showed that spina block with 0.5% hyperbaric bupivacaine for Cesarean section combined with intravenous infusion norepinephrine had higher cardiac output than those who received phenylephrine

Official Title
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Cardiac Output Changes During Hyperbaric and Isobaric Bupivacaine in Patients Undergoing Cesarean Section: An Randomization Trials

Conditions
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Cardiac Output, Hypotension, Anesthesia, Spinal

Intervention / Treatment
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* Drug: Isobaric marcaine
* Drug: Hyperbaric marcaine


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: American Society of Anesthesiology classification I - II Elective or urgency Cesarean section with spinal block e.g. cephalopelvic disproportion, premature rupture of membrane Singleton pregnancy Body mass index < 40 kg/m2 Exclusion Criteria: Pregnancy <35 weeks gestational age Hypertensive disease e.g. gestational hypertension, chronic hypertension, preeclampsia History of allergy to the study drugs

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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Female

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: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Isobaric Marcaine<br>Isobaric Marcaine 2.2 mL for spinal block | Drug: Isobaric marcaine<br>* Isobaric marcaine 2.2 mL for spinal block<br>* Other names: bupivacaine;|
| Active Comparator: Hyperbaric Marcaine<br>Hyperbaric Marcaine 2.2 mL for spinal block | Drug: Hyperbaric marcaine<br>* Hyperbaric marcaine 2.2 mL for spinal block<br>* Other names: bupivacaine;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change of cardiac output (L/min) after spinal block | The investigators will measure cardiac output using non-invasive methods (USCOM) before spinal block and 5 minutes after spinal block. | 5 minutes after spinal block | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Total dose of vasopressor | The investigators will record the total dose that treat hypotension during preoperative period | 2 hours | 
| Number of patients who experience systolic blood pressure < 25% of preoperative measurement | The investigators will monitor blood pressure at interval; before spinal block, then after spinal block every 1 minute for 10 for 10 times, every 2 minute for 5 times, every 3 minutes until delivery then every 5 minutes til the end of surgery. If the patient's systolic blood pressure is declined, vasopressor will be given. | 2 hours | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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isobaric marcaine, hyperbaric marcaine