Fluid therapy guided by stroke volume response to repeated fluid challenges is used for hemodynamic optimization during general anesthesia. Two types of devices that measure stroke volume non-invasively are primarily available for intermediate-risk surgery under general anesthesia. They are based on two different techniques, (1) pulse contour analysis, and (2) transthoracic bioimpedance. They have never been compared with each other. Therefore, it is not known (1) whether they are interchangeable for the measurement of stroke volume changes (usually assessed as the "concordance" of two techniques), and (2) whether one is better than the other. The aim is to study the concordance of these two non-invasive hemodynamic devices. it will use both of them in patients undergoing intermediate risk surgery. They will be tested during modifications of cardiac preload induced by Trendelenburg and anti-Trendelenburg positioning, as well as during intraoperative fluid challenges, vasopressor boluses and alveolar recruitment maneuvers.
The main objective is to assess the concordance of two non-invasive devices using the technology described above : the Clearsight (Edwards Lifesciences, pulse contour analysis), and the Niccomo (Medis, bioimpedance). Both will be used in each patient included in the study. They will be tested during modifications of cardiac preload induced by sequences of position changes (see below) including Trendelenburg and anti-Trendelenburg positioning, performed systematically before and after the procedure, as well as during fluid challenges, vasopressor boluses and alveolar recruitment maneuvers (performed during the procedure according to the needs of the anesthesiologist in charge of the patient). Both monitors will also be compared with an invasive monitor of stroke volume (Vigileo/Flotrac, Edwards Lifesciences), and the respiratory pulse pressure variation will also be measured during the sequences of position changes and will be used as a gold standard for fluid responsiveness.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
DIAGNOSTIC
Masking
SINGLE
Enrollment
30
Starting from 0° position, shift to position +20°, then tilt to -20°, and finally back to the 0° position.
Starting from 0° position, shift to position -20°, then tilt to +20°, and finally back to the 0° position and collect the last group of figures.
Hôpital Roger Salengro, CHU Lille
Lille, France
concordance of stroke volume changes measured with each monitor during the standardized maneuvers of sequences A and B (total: 6 observations per individual).
4-quadrant plot
Time frame: during each changes of positioning (i.e., for 1-2 minutes in each condition, for a total of 10-15 minutes following initial measurements in basal conditions), during sequences A and B
Fluid responsiveness defined by areas under the Receiver Operating Characteristic curve (sensitivity and specificity)
Comparison of areas under the Receiver Operating Characteristic curve (sensitivity and specificity). Each maneuver will be classified as "responder" or "nonresponder" according to the value of Pulse Pressure Variation (PPV) recorded before the maneuver and to the changes in PPV during the maneuver (as previously published)
Time frame: during each changes of positioning (i.e., for 1-2 minutes in each condition, for a total of 10-15 minutes following initial measurements in basal conditions), during sequences A and B
concordance of stroke volume changes measured with each monitor during the standardized maneuvers mimicking preload decrease.
4-quadrant plot
Time frame: during each changes of positioning where cardiac preload is supposed to decrease (i.e., for 1-2 minutes in one out of two condition, for a total of 10-15 minutes following initial measurements in basal conditions), during sequences A and B
concordance of stroke volume changes measured with each monitor during the standardized maneuver mimicking preload increase.
4-quadrant plot
Time frame: during each changes of positioning where cardiac preload is supposed to increase (i.e., for 1-2 minutes in one out of two condition, for a total of 10-15 minutes following initial measurements in basal conditions), during sequences A and B
concordance of stroke volume changes measured with each monitor during the surgical procedure (fluid challenges, vasopressor boluses, alveolar recruitment maneuver).
4-quadrant plot
Time frame: throughout surgery (mean length expected between 3 and 5 hours). Measurements performed during sequences of 5-20 minutes that can occur several times during surgery
interchangeability of stroke volume measurements with each monitor during sequences A and B
Bland and Altman plot for repeated measures
Time frame: before and after each changes of positioning (i.e., for 1-2 minutes in each condition, for a total of 10-15 minutes following initial measurements in basal conditions), during sequences A and B
interchangeability of stroke volume measured with each monitor during the surgical procedure (fluid challenges, vasopressor boluses, alveolar recruitment maneuver).
Bland and Altman plot for repeated measures
Time frame: throughout surgery (mean length expected between 3 and 5 hours). Measurements performed before and after sequences of 5-20 minutes that can occur several times during surgery
concordance of stroke volume changes measured with each monitor with that measured by a Vigileo/Flotrac monitor during the standardized maneuvers of sequences A and B (total: 6 observations per individual).
4-quadrant plot
Time frame: during each changes of positioning (i.e., for 1-2 minutes in each condition, for a total of 10-15 minutes following initial measurements in basal conditions), during sequences A and B
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.