Non-invasive Cardiac Output Monitoring in Obstetric Patients

Study Overview
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Brief Summary
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The investigators hypothesize that continuously measuring stroke volume (SV) and cardiac output (CO) will 1) reveal hemodynamic instability in a timely manner and alert the physician promptly, 2) provide information for the physician to make the differential diagnosis as to whether the hemodynamic instability was due to vasodilatation or reduction of venous blood return, and 3) lead to appropriate and prompt treatment to improve patient outcome. -determine the SV and CO and their kinetic change using ICON® to establish a hemodynamic profile of the patient under spinal anesthesia for cesarean section. To determine if using instantaneous measurements of SV and CO to guide patient management improves hemodynamic stability.

Official Title
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Using Thoracic Electrical Bioimpedance to Measure Stroke Volume and Cardiac Output in Patients Under Spinal Anesthesia for Cesarean Section

Conditions
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Complications; Cesarean Section, Anesthesia; Adverse Effect, Spinal and Epidural

Intervention / Treatment
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* Procedure: experimental
* Procedure: Control


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: age 18-45; receiving spinal anesthesia or combined spinal and epidural anesthesia to undergo cesarean section Exclusion Criteria: Patients who have major cardiovascular disease,preexisting of hypertension or gestational hypertension, preeclampsia and body mass index greater than 35kg/m2; Patients who have skin lesion at the place where the electrode is supposed to be applied; Emergency cesarean section patients.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 45 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: Diagnostic
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Control<br>The patients in Group A will serve as controls and will receive standard monitoring in addition to continuous measurement of SV and CO. The physicians will not know the CO and SV and will manage the patients in a standard fashion. | Procedure: Control<br>* Data obtained from the non-invasive cardiac output monitor,ICON®, are not available for the anesthesia care providers.<br>|
| Experimental: experimental<br>The patients in Group B will receive the same monitoring as those in Group A. But the physicians will know instantaneously the CO and SV in real time and will manage the patients accordingly. | Procedure: experimental<br>* Non-invasive cardiac output monitoring using thoracic electric bioimpedance analysis via ICON® in addition of the standard monitoring during cesarean section.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Maximum percentage changes in mean blood pressure after spinal anesthesia |  | baseline before spinal anesthesia and up to 20 minutes after spinal anesthesia | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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thoracic electric bioimpedance, cardiac output monitoring, cesarean section, spinal anesthesia