A Comparison of Thoracic Electrical Bioimpedance and FloTrac/Vigileo

Study Overview
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Brief Summary
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Stroke volume variation (SVV) is an indicator used to assess the patient's volume status. The FloTrac system (Edwards Lifesciences, Irvine, CA) continuously monitors cardiac output (CO) and SVV (SVV-FloTrac) by analyzing the systemic arterial pressure wave. Numerous studies have demonstrated that SVV-FloTrac serves as a reliable indicator of fluid responsiveness. However, its peripheral invasiveness raises concerns about susceptibility to reflecting waves, damping, and vascular tone influences.In contrast, Transthoracic electrical bioimpedance (BioZ.com™) offers a non-invasive approach for continuously monitoring various hemodynamic variables. In this study, the primary aim was to assess the agreement between simultaneously measured SVV-FloTrac and SVV-BioZ.

Official Title
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A Comparison of Stroke Volume Variation for Prediction of Fluid Responsiveness Measured by Thoracic Electrical Bioimpedance and FloTrac/Vigileo

Conditions
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Stroke Volume Variation, SVV-FloTrac, Thoracic Electrical Bioimpedance, Fluid Responsiveness

Intervention / Treatment
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* Device: Flotrac Group
* Device: BioZ Group


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age 18≤ Age ≤65. patients undergoinglaparoscopic elective surgery for gastrointestinal tumors under general anesthesia 18 kg/m2≤BMI≤30 kg/m2 ASA classification I-III Patients signed informed consent form Exclusion Criteria: Arrhythmias The patient is diagnosed with severe cardiovascular disease（pulmonary arterial hypertension、left ventricular ejection fraction< 50%、aortic aneurysm、extensive peripheral arterial occlusive disease,、significant valvulopathy） Severe heart failure (METS<4) The patient is diagnosed with severe hepatic dysfunction (ChildePugh class C) The patient is diagnosed with severe renal dysfunction (undergoing dialysis before surgery) There is an infectious lesion on the skin or subcutaneous tissue where the non-invasive electrode piece is placed History of allergy to anesthetic drugs Weight<40kg Allergies to 6% hydroxyethyl starch, Fresenius Kabi, Deutschland

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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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Flotrac Group<br>In this group,an arterial catheter was inserted preoperatively. An indwelling radial artery catheter was connected to the hemodynamic monitoring system (EV1000; Edward Lifesciences Corp., Irvine, CA, USA) via FloTrac™ (Edwards Lifesciences Corp.) sensors. | Device: Flotrac Group<br>* Haemodynamic parameters were collected simultaneously by the Flotrac monitoring.<br>|
| Experimental: BioZ Group<br>In this group,haemodynamic parameters were collected simultaneously by the thoracic bioimpedance (BioZ.com™) monitoring. | Device: BioZ Group<br>* Haemodynamic parameters were collected simultaneously by the thoracic bioimpedance (BioZ.com™)monitoring.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The agreement between simultaneously measured SVV-FloTrac and SVV-BioZ | After anesthesia induction, volume loading was initiated. For each volume loading step (VLS), 100 mL of colloid solution (6% hydroxyethyl starch) was administered over a 2-minute duration. The SVV was measured and recorded simultaneously by FloTrac (SVV-FloTrac) and Transthoracic electrical bioimpedance(SVV-BioZ). Volume loading steps (VLS) continued until no responsive VLS was observed. Responsive VLS, defined as an increase in Flotrac-SV by at least 5%, and nonresponsive VLS, characterized by no change or an increase in Flotrac-SV by less than 5%, were subsequently identified. Multiple analysis methods were used to determine the agreement of the two SVVs. | From anesthesia induction to the nonresponsive VLS about one hour. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The capacity to predict fluid responsiveness. | After anesthesia induction, volume loading was initiated. For each volume loading step (VLS), 100 mL of colloid solution (6% hydroxyethyl starch) was administered over a 2-minute duration. The SVV was measured and recorded simultaneously by FloTrac (SVV-FloTrac) and Transthoracic electrical bioimpedance(SVV-BioZ). Volume loading steps (VLS) continued until no responsive VLS was observed. Responsive VLS, defined as an increase in Flotrac-SV by at least 5%, and nonresponsive VLS, characterized by no change or an increase in Flotrac-SV by less than 5%, were subsequently identified. Multiple analysis methods were used to determine the capacity to predict the fluid responsiveness of these two devices. | From anesthesia induction to the nonresponsive VLS about one hour. |