A Comparison of Thoracic Electrical Bioimpedance and FloTrac/Vigileo

RenJi Hospital100 enrolled

Overview

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.

Study Type

INTERVENTIONAL

Allocation

NON_RANDOMIZED

Purpose

DIAGNOSTIC

Masking

NONE

Enrollment

100

Conditions

Stroke Volume Variation SVV-FloTrac Thoracic Electrical Bioimpedance Fluid Responsiveness

Eligibility

Sex: ALLMin age: 18 YearsMax age: 65 Years

Medical Language ↔ Plain English

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

Outcomes

Primary Outcomes

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.

Time frame: From anesthesia induction to the nonresponsive VLS about one hour.

Secondary Outcomes

The capacity to predict fluid responsiveness.