Stroke volume is a major determinant of tissue perfusion and therefore a key parameter to monitor in patients with hemodynamic instability and hypoperfusion. Left Ventricular Outflow Tract (LVOT) Velocity-Time Integral (VTI) measured using pulsed wave Doppler is widely used as an estimation of stroke volume and should be a competence required for every Intensive Care Unit (ICU) physician. Recently, research in Artificial Intelligence (AI) applied to medical imaging constituted a breakthrough in the acquisition of images. The goal of the present study is to characterize and quantify the reliability and reproducibility of LVOT VTI measurements by comparing the measures obtained by minimally-trained operators and expert physicians, guided by UltraSight AI software.
The main goal of Intensive Care Unit (ICU) physicians is to ensure cellular oxygenation by maintaining adequate organ perfusion in their patients. Stroke volume is a major determinant of tissue perfusion and therefore a key parameter to monitor in patients with hemodynamic instability. Left Ventricular Outflow Tract (LVOT) Velocity-Time Integral (VTI) measured using pulsed wave Doppler is widely used as an estimation of stroke volume to assess hemodynamic modifications. This value reflects the stroke distance, which varies proportionately to stroke volume in case of hemodynamic variations resulting from therapeutic interventions (fluid administration, vasoactive drugs…) or disease processes. An increase in stroke volume (or LVOT VTI) is expected in response to fluid administration and attests for its efficacy. A lack of increase indicates that the cardiovascular system is no longer fluid-responsive, and that fluid administration is not improving tissue perfusion and creates congestion. Therefore, measuring aortic VTI should be a competence required for every ICU physician. However, international ICU guidelines on echocardiography do not consider LVOT VTI measurement as a basic skill but rather as a competence of advanced operators. More recently, the European Society of Intensive Care Medicine published expert recommendations on echocardiography, setting the evaluation of LVOT VTI as basic skill but with a weak recommendation, lacking published evidence to support this statement. The main difficulty in measuring LVOT VTI is obtaining an adequate apical 5-chamber view. Recently, research in artificial intelligence (AI) applied to medical imaging constituted a breakthrough in the acquisition of images. UltraSight is a company specialized in AI applied to echocardiography. Their software is based on neural network using machine learning to analyse extremely precisely the image obtained by an operator. The software indicates to the operator in real time on-screen how to optimize the image by mobilizing the probe until the desired view is correctly obtained, with the best quality. The main objective of the present study is to characterize and to quantify the reliability and reproducibility of LVOT VTI measurements by comparing the measures obtained by minimally trained operators and experts, using an ultrasound platform equipped with real-time AI-based guidance (UltraSight). If interchangeability of minimally trained operators and expert measurements can be demonstrated, this will constitute a strong basis to upgrade the measurement of LVOT VTI as a basic competence in critical care ultrasound. The secondary objectives are to assess the concordance of therapeutic decisions made by the ICU clinician in charge of the patient (i.e.: continue or interrupt fluid administration) based on the VTI variation obtained by the minimally-trained operator, and that based on the VTI variation obtained by the expert, the agreement of the absolute value of the measure of LVOT VTI obtained by the minimally trained operators and the experts, the correlation between the measures of the VTI variation (% change following a fluid challenge of 250 mL or a passive leg-raising test) between the minimally-trained operators and those obtained by experts.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
OTHER
Masking
TRIPLE
Enrollment
100
Patients in whom fluid administration is considered necessary, based on hypoperfusion criteria will be included in the trial. One member of group A and one of group B will proceed independently to evaluate LVOT VTI, guided by the UltraSight AI software to obtain the best 5-chamber view. The measure of LVOT VTI will be calculated as the average of three consecutive cardiac cycles. The order of acquisition between group A and B will be randomized. Each operator will be blinded to the values obtained by the other. After baseline LVOT VTI measurement, a 250 mL fluid challenge of crystalloids or a passive leg raising test (non-pharmacological and reversible fluid challenge of roughly 250 mL), depending on the appreciation of the clinician will be performed. Measurements will be repeated immediately after the fluid challenge by the same operators, still blinded to each other, guided by the UltraSight AI software. The order of the 2nd acquisition will be the same as the 1st acquisition
CHU de Limoges
Limoges, France
NOT_YET_RECRUITINGHôpital Lariboisière - APHP
Paris, France
RECRUITINGHôpital européen Georges Pompidou - APHP
Paris, France
RECRUITINGRelative difference expressed in percentage of LVOT VTI measurement evaluated by the minimally trained operators as compared with LVOT VTI measurement by experts.
To assess the equivalence of measures of LVOT VTI obtained by minimally trained operators as compared with those obtained by the experts, both guided by artificial intelligence. Both measures of VTI pre and post-fluid challenge will be considered.
Time frame: Less than 60 minutes
The relative difference expressed in percentage of LVOT VTI measurement, pre-fluid challenge, evaluated by the minimally trained operators as compared with those obtained by experts.
To assess the equivalence of the individual measures of LVOT VTI, pre-fluid challenge, obtained by the minimally trained operators as compared with those obtained by the experts, both guided by artificial intelligence.
Time frame: Less than 60 minutes
The relative difference expressed in percentage of LVOT VTI measurement, post-fluid challenge, evaluated by the minimally trained operators as compared with those obtained by experts.
To assess the equivalence of the individual measures of LVOT VTI, post-fluid challenge, obtained by the minimally trained operators as compared with those obtained by the experts, both guided by artificial intelligence.
Time frame: Less than 60 minutes
Difference in the VTI variation [i.e.: % change after a fluid challenge of 250 mL, or a passive leg-raising test] obtained by the minimally-trained operators and that obtained by experts.
To quantify the reproducibility of LVOT VTI measurements between minimally trained operators and experts.
Time frame: Less than 60 minutes
Correlation of the measure of the VTI variation before and after a fluid challenge of 250 mL or after a passive leg-raising test between the minimally trained operators and the experts.
Correlation of the measures of the VTI variation before and after a fluid challenge of 250 mL or after a passive leg-raising test between the minimally-trained operators and the experts will be analyzed using the intraclass correlation coefficient and its associated 95% confidence interval. Pearson and Spearmann correlation coefficients will also be calculated.
Time frame: Less than 60 minutes
Difference of the absolute value of the measure of LVOT VTI obtained by the minimally trained operators and the experts.
Agreement of the absolute value of the measure of LVOT VTI obtained by the minimally trained operators and the experts using the Bland and Altman's method (bias ± limits of agreement).
Time frame: Less than 60 minutes
Concordance in therapeutic decision by the blinded attending physician based on the measure of the VTI variation by the minimally trained operators compared to experts.
Concordance in therapeutic decision by blinded attending physician (i.e.: continue or interrupt fluid administration) based on the measure of the VTI variation by the minimally trained operators compared to experts will be analyzed using the sensitivity and specificity as well as the negative and positive predictive values and its associated 95% confidence interval. The reference is the decision based on the value obtained by the expert.
Time frame: Less than 60 minutes
Percentage of pairs (minimally-trained/expert) with difference of measurement: o < -14% o [-14%; 14%] o > 14%
Percentage of pairs minimally trained/expert with difference of measurement will be described with the following thresholds: * \< -14% * \[-14%; 14%\] * \> 14%
Time frame: Less than 60 minutes
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