Increase In Velocity Time Integral Research Articles

Long-term myocardial performance of the systemic right ventricle during exercise in patients with transposition of the great arteries and atrial switch operation

ObjectiveThe echocardiographic assessment of the systemic right ventricle (sRV) performance during stress testing is limited and evaluation is not routinely performed. The aim of the study is to investigate sRV myocardial performance at rest and with exercise in patients with complete transposition of the great arteries (dTGA) who have undergone atrial switch operation. MethodsIn a single-center cross-sectional study, 41 patients with dTGA following the atrial switch operation and gender-matched 20 healthy volunteers underwent exercise echocardiography on a bicycle ergometer in the semi-supine position to assess sRV systolic function indices: tricuspid annular plane systolic excursion (TAPSE), right ventricular area change (FAC), global longitudinal strain (GLS) and systemic velocity time integral (VTI). ResultsPatients with sRV were characterized by lower systolic function assessed by TAPSE, s’, FAC, GLS both at baseline and at peak exercise, compared with the control group. sRV GLS decreased during exercise in patients with sRV (−6 + 2.84) compared to increased in patients with systemic left ventricle (0.47 + 2.74), p < 0.001. There was no increase in VTI during exercise in patients with sRV, compared to controls (Δ VTI −0.01 ± 2.96 cm vs. Δ VTI 4.50 ± 3.13 cm, p < 0.001). There was a trend towards higher chronotropic incompetence in patients with sRV vs. control (61% vs. 45%, p = 0.28). ConclusionOur results confirmed that patients with dTGA have reduced ability to increase myocardial contractility and stroke volume during exercise. Chronotropic incompetence was prevalent in dTGA patients.

Effect of volume infusion on left atrial strain in acute circulatory failure

BackgroundLeft atrial strain (LAS) is a measure of atrial wall deformation during cardiac cycle and reflects atrial contribution to cardiovascular performance. Pathophysiological significance of LAS in critically ill patients with hemodynamic instability has never been explored. This study aimed at describing LAS and its variation during volume expansion and to assess the relationship between LAS components and fluid responsiveness.MethodsThis prospective observational study was performed in a French ICU and included patients with acute circulatory failure, for whom the treating physician decided to proceed to volume expansion (rapid infusion of 500 mL of crystalloid solution). Trans-thoracic echocardiography was performed before and after the fluid infusion. LAS analysis was performed offline. Fluid responsiveness was defined as an increase in velocity-time integral (VTI) of left ventricular outflow tract ≥ 10%.ResultsThirty-eight patients were included in the final analysis. Seventeen (45%) patients were fluid responders. LAS analysis had a good feasibility and reproducibility. Overall, LAS was markedly reduced in all its components, with values of 19 [15 – 32], -9 [-19 – -7] and − 9 [-13 – -5] % for LAS reservoir (LASr), conduit (LAScd) and contraction (LASct), respectively. LASr, LAScd and LASct significantly increased during volume expansion in the entire population. Baseline value of LAS did not predict fluid responsiveness and the changes in LAS and VTI during volume expansion were not significantly correlated.ConclusionsLAS is severely altered during acute circulatory failure. LAS components significantly increase during fluid administration, but cannot be used to predict or assess fluid responsiveness.

Caudal vena cava measurements and fluid responsiveness in hospitalized cats with compromised hemodynamics and tissue hypoperfusion.

To evaluate the use of the caudal vena cava collapsibility index (CVCCI) and the inspiratory/minimum and expiratory/maximum diameters of the vena cava to predict fluid responsiveness in hospitalized, critically ill cats with hemodynamic and tissue perfusion abnormalities. Diagnostic test study in a prospective cohort of hospitalized cats. Private practice referral hospital. Twenty-four hospitalized cats with spontaneous breathing and compromised hemodynamics and tissue hypoperfusion. Ultrasonographic examination before and after fluid expansion with 10ml/kg of lactated Ringer's solution. Fluid responsiveness was evaluated using the velocity-time integral (VTI) of the subaortic blood flow, by measuring it before and after a fluid load of 10ml/kg of lactated Ringer's solution. The CVCCI was calculated using the following formula: (maximum diameter-minimum diameter / maximum diameter)×100. Ten cats were fluid responders (42 %) and 14 were nonresponders (58 %). The area under the receiver operating characteristic curve (AUROC) with their 95% confidence interval for the predictors and the best cutoff values were as follows: CVCCI, AUROC=0.83 (0.66-1.00) and cutoff=31%; inspiratory/minimum diameter, AUROC=0.86 (0.70-1.00) and cutoff=0.24cm; expiratory/maximum diameter, AUROC=0.88 (0.74-1.00) and cutoff=0.22cm. A significant lineal correlation was observed between the percentage of increase in VTI after expansion and CVCCI (rs =0.68, P<0.001), expiratory/maximum diameter (rs =-0.72, P<0.001), and inspiratory/minimum diameter (rs =-0.71, P<0.001). The intraobserver and interobserver variability was low for VTI, and the expiratory/maximum diameter and inspiratory/minimum diameter were high for CVCCI. Caudal vena cava measurements could be useful to predict the response to fluids in hospitalized cats with hemodynamic and tissue perfusion alterations. Additional studies are required to draw definitive conclusions about the role of these variables to guide fluid administration in cats.

Echocardiographic indicators of fluid responsiveness in hospitalized dogs with compromised hemodynamics and tissue hypoperfusion.

To evaluate the accuracy of selected echocardiographic variables used to predict fluid responsiveness in hospitalized dogs with compromised hemodynamics and tissue hypoperfusion. Diagnostic test study in a prospective cohort of hospitalized dogs. Veterinary referral clinics. Forty-four hospitalized dogs with compromised hemodynamics and tissue hypoperfusion were utilized in this study. Echocardiographic examination before and after fluid replacement with 30ml/kg of lactated Ringer's solution. Pre-fluid replacement measurements of velocity of transmitral E wave (E-peak), the left ventricular end-diastolic internal diameter normalized to body weight (LVIDdN), and the left ventricular end-systolic internal diameter normalized to body weight (LVIDsN) were significantly lower in fluid-responsive patients compared with nonresponders (P<0.001). The area under the receiver operating characteristic curve (AUROC) with its 95% confidence interval (CI) for each significant predictor was as follows: E-peak 0.907 (0.776-1.000, P<0.001) and LVIDdN 0.919 (0.801-1.000, P<0.001). The predictive capacity of LVIDsN was not significantly better than chance (AUROC, 0.753; 95% CI, 0.472-1.000, P=0.078). A significant negative linear correlation was observed between the percentage of increase in velocity-time integral after expansion and the echocardiographic variables LVIDdN (rs =-0.452, P =0.023) and E-peak (rs =-0.396, P=0.008) pre-fluid replacement. The intraobserver and interobserver variability was very low(<5 %) for all measurements. In this study using critically ill dogs with compromised hemodynamics and tissue hypoperfusion, pre-fluid replacement measurements of LVIDdN and E-peak adequately predict fluid responsiveness. Because a small number of fluid nonresponders were involved in the present study (11.4%), further studies that include larger numbers of fluid-nonresponsive animals are required.

Venous Segmental Flow Changes after Superficial Venous Intervention Demonstrating by Quantitative Phase-Contrast Magnetic Resonance Analysis: Preliminary Data from a Longitudinal Cohort Study.

The effects of superficial venous intervention on hemodynamics can be quantified using two-dimensional phase-contrast magnetic resonance imaging (2D PC-MRI). Twelve patients received pre- and postintervention 2D PC-MRI analysis using quantitative hemodynamic parameters. Fifteen healthy volunteers served as controls. The 2D PC-MRI results of the target limbs (limbs scheduled for intervention for venous reflux) differed from those of the controls in terms of stroke volume (SV), forward flow volume (FFV), absolute stroke volume (ASV), and mean flux (MF) in all venous segments. The velocity time integral (VTI) and mean velocity (MV) of the popliteal vein (PV) segments were similar between the target limbs and controls preoperatively. After intervention, the target limbs exhibited an increase in VTI and MV in the femoral vein (FV) and PV segments. We compared the target and nontreated limbs of the individual patients preoperatively and postoperatively to minimalize individual bias. All QFlow parameter ratios in the FV segment increased after venous intervention (VTI, p = 0.025; MV, p = 0.024). In the PV segment, FFV and ASV increased significantly (p = 0.035 and 0.024, respectively). After interventions, the volume (FFV and ASV) of the PV segment and the efficiency (VTI and MV) of the FV segment significantly increased.

Normal Values and Patterns of Normality and Physiological Variability of Mitral and Tricuspid Inflow Pulsed Doppler in Healthy Children.

Background: While mitral (MV) and tricuspid valve (TV) pulsed Doppler velocities and derived gradients are commonly evaluated, data on normal pediatric values are limited. This study aimed to evaluate the normal values and physiological variability for MV and TV Doppler velocities and derived gradients in a large cohort of prospectively enrolled healthy children. Methods: The echocardiographic measurements included pulsed Doppler MV and TV E and A velocities, E deceleration times (EDT), maximal and mean gradients, and velocity time integral (VTI). Results: A total of 544 healthy subjects (median age 6.4 years, range 1 day–17.68 years) were included. MV and TV E velocity, E/A ratio, and E and A wave duration increased, while A velocity decreased with age (p < 0.001). Along with an increase in VTI, there occurred a progressive increase in maximum velocity and gradients and a decrease in mean velocities and gradients. E/A inversions were common, especially at the TV in neonates and infants. For MV, inversion in either one, two, or three consecutive beats occurred in 51.9% of neonates and 18.3% of infants, while it was rare at older ages (all p < 0.001). For TV, inversions in three consecutive beats occurred in 71.4% of neonates, while inversions in only one or two beats were more common in infants (27.3%). For TV, inversion in one or more beats, however, was not infrequent at all ages. Conclusions: We report normal values and patterns of normality and physiological variability for MV and TV inflow Doppler from a large population of healthy children.

304 Lack of Early Left Ventricular Outflow Tract Velocity Time Integral Estimated Volume Responsiveness is Associated With Increased Morbidity and Mortality

Fluid boluses are amongst the strongest recommendations for the management of septic patients, and they are generally administered with the goal increasing cardiac output and improving tissue perfusion. Early identification of volume responsiveness is challenging and dependent on many patient factors, but it may prevent the harmful consequences of hypervolemia. Left ventricular outflow tract (LVOT) velocity time integral (VTI) has been used as a predictor of volume responsiveness. The purpose of this study was to determine whether lack of volume responsiveness, defined as ≤15% change in LVOT VTI, is associated with increased risk of mortality, admission to an intensive care unit (ICU), or rapid response team activation within 24 hours of hospital arrival (composite outcome measure). We hypothesize that septic patients who are not volume responders will be more critically ill and therefore at greater risk of experiencing the composite outcome. This is a prospective observation study of septic patients conducted in an academic emergency department (ED). Patients were eligible for enrollment if they met Sepsis 3 definition and were receiving intravenous fluids. Patients received a point-of-care echocardiogram to measure LVOT VTI. Three measurements were taken and the average was recorded. After patients received a 500mL fluid bolus, a repeat ultrasound was conducted to re-measure VTI. Volume responsiveness was defined as >15% increase in VTI. Chart review was performed on all enrolled patients to determine whether the composite outcome occurred within 24 hours of ED arrival. At total of 126 patients with repeat ultrasound exams were included in this analysis; 49.2% were female and median age was 74 years. Overall, 56 (44.4%) patients experienced the composite primary outcome within 24 hours, and 30 (23.8%) patients had a delta VTI of >15%. Among the patients who experienced the composite outcome, 82.1% of them had a delta VTI of ≤15%, compared with 71.4% of patients who did not experience the composite outcome (p-value = 0.160). In a multivariable logistic regression modeling adjusting for lactate and systolic blood pressure, delta VTI of ≤15%, compared with delta VTI >15%, was significantly associated with higher odds of mortality, ICU admission, or rapid response team activation within 24 hours (OR: 2.643; 95% CI: 1.002, 6.967). Septic ED patients who are not volume responsive, based on percent change in VTI, are more likely to experience mortality, be admitted to an ICU, or have a rapid response team activation within 24 hours of ED arrival. Our findings suggest that early VTI may be used in septic patients to predict their clinical course. Future endeavors may evaluate if initial change in VTI could be used to help emergency physicians identify this critically ill cohort and facilitate earlier ICU disposition and vasopressor administration.

Changes in pulse pressure variation to assess preload responsiveness in mechanically ventilated patients with spontaneous breathing activity: an observational study

BackgroundPulse pressure variation (PPV) is not reliable in predicting preload responsiveness in patients receiving mechanical with spontaneous breathing (SB) activity. We hypothesised that an increase in PPV after a tidal volume (VT) challenge (TVC) or a decrease in PPV during passive leg raising (PLR) can predict preload responsiveness in such cases. MethodsThis prospective observational study was performed in two ICUs and included patients receiving mechanical ventilation with SB, for whom the treating physician decided to test preload responsiveness. Transthoracic echocardiography was used to measure the velocity–time integral (VTI) of the left ventricular outflow tract. Patients exhibiting an increase in VTI ≥12% during PLR were defined as PLR+ patients (or preload responders). Then, a TVC was performed by increasing VT by 2 ml kg−1 predicted body weight (PBW) for 1 min. PPV was recorded at each step. ResultsFifty-four patients (Simplified Acute Physiology Score II: 60 (25) ventilated with a VT of 6.5 (0.8) ml kg−1 PBW, were included. Twenty-two patients were PLR+. The absolute decrease in PPV during PLR and the absolute increase in PPV during TVC discriminated between PLR+ and PLR– patients with area under the receiver operating characteristic (AUROC) curve of 0.78 and 0.73, respectively, and cut-off values of –1% and +2%, respectively. Those AUROC curve values were similar but were significantly different from that of baseline PPV (0.61). ConclusionIn patients undergoing mechanical ventilation with SB activity, PPV does not predict preload responsiveness. However, the decrease in PPV during PLR and the increase in PPV during a TVC help discriminate preload responders from non-responders with moderate accuracy. Clinical trial registrationNCT04369027 (ClinicalTrials.gov).

Change in left ventricular velocity time integral during Trendelenburg maneuver predicts fluid responsiveness in cardiac surgical patients in the operating room.

Fluid responsiveness is an important topic for clinicians. We investigated whether changes in left ventricular outflow tract (LVOT) velocity time integral (VTI) during a Trendelenburg position (TP) maneuver can predict fluid responsiveness as a non-invasive marker in coronary artery bypass graft (CABG) surgery patients in the operating room. This prospective, single-center observational study, performed in the operating room, enrolled 65 elective CABG patients. Hemodynamic data coupled with transesophageal echocardiography monitoring of the LVOT VTI and the peak velocity were collected at each step [baseline 1, TP, baseline 2 and fluid challenge (FC)]. Patients whose VTI increased ≥15% after FC (500 mL of Gelofusine infusion within 30 min) were considered responders. Twenty-eight (43.1%) patients were responders to fluid administration. VTI changes during the TP maneuver predicted fluid responsiveness with an area under the receiver operating characteristic curve (AUC) of 0.90 (95% CI, 0.79-0.96), with a sensitivity of 100%, and a specificity of 70% at a threshold of 10% (gray zone, 8-15%). The increase in VTI during the TP was correlated with the VTI changes induced by FC (r=0.61, P<0.0001). Changes in peak velocity and pulse pressure during the TP were poorly predictive of fluid responsiveness, with an AUC of 0.72 (95% CI: 0.60-0.82) and 0.66 (95% CI: 0.53-0.77), respectively. An increase in VTI induced by the TP could predict fluid responsiveness in CABG patients in the operating room. However, changes in peak velocity and pulse pressure stimulated by the TP could not reliably predict fluid responsiveness.

Measurement of coronary sinus blood flow using transesophageal echocardiography to estimate the adequacy of revascularization in patients undergoing off-pump coronary artery bypass grafting

Introduction Revascularization of coronary artery increases the blood flow in the coronary sinus (CS) too. The study aimed to measure the CS blood flow using transesophageal echocardiography (TEE) to estimate the adequacy of revascularization in patients undergoing off-pump coronary artery bypass grafting. Patients and methods After ethical committee approval, 100 patients scheduled for elective coronary artery bypass grafting were included in this study. After induction of balanced anesthesia according to institutional protocol, a 5-Hz multiplane phased-array TEE probe was inserted into patients’ esophagus, and the following parameters were calculated at pre-revascularization and post-revascularization periods: velocity time integral of CS, coronary sinus diameter, coronary sinus cross-section area, and coronary sinus blood flow (CSBF) per beat and per minute. Results Our study showed a statistically significant increase in velocity time integral in the post-revascularization period as compared with the pre-revascularization period (P Conclusion TEE is a superior modality to evaluate CSBF before and after coronary artery bypass revascularization to determine the adequacy of surgical revascularization in real time during off-pump coronary artery bypass revascularization.

Caudal vena cava collapsibility index as a tool to predict fluid responsiveness in dogs.

To evaluate the use of the caudal vena cava collapsibility index (CVCCI) as a predictor of fluid responsiveness in hospitalized, critically ill dogs with hemodynamic or tissue perfusion abnormalities. Retrospective observational study. Private referral center. Twenty-seven critically ill, spontaneously breathing dogs with compromised hemodynamics or tissue hypoperfusion. None. The electronic medical records were searched for dogs admitted for any cause, from August 2016 to December 2017. We included dogs with ultrasound measurements of: CVCCI, performed at baseline; and velocity time integral (VTI) of the subaortic blood flow, carried out before and after a fluid load. CVCCI was estimated as: (maximum diameter-minimum diameter/maximum diameter) × 100. Dogs in which VTI increased ≥15% were considered fluid responders. The CVCCI accurately predicted fluid responsiveness with an area under the receiver operating characteristic curve of 0.96 (95% CI, 0.88 to 1.00). The optimal cut-off of CVCCI that better discriminated between fluid responders and nonresponders was 27%, with 100.0% sensitivity and 83.3% specificity. At baseline, fluid responders had lower VTI (5.48 [4.26 to 7.40] vs 10.61 [7.38 to 13.23] cm, P=0.004) than nonresponders. The basal maximum diameter of the caudal vena cava adjusted to body weight was not different between responders and nonresponders (0.050 [0.030 to 0.100] vs 0.079 [0.067 to 0.140] cm/kg, P=0.339). The increase in VTI was related to basal CVCCI (R=0.60, P=0.001). Bland-Altman analysis showed narrow 95% limits of agreement between measurements of CVCCI and VTI performed by different observers or by the same observer. The results of this small cohort study suggest that CVCCI can accurately predict fluid responsiveness in critically ill dogs with perfusion abnormalities. Further research is necessary to extrapolate these results to larger populations of hospitalized dogs.

Increase in Central Venous Pressure During Passive Leg Raising Cannot Detect Preload Unresponsiveness.

By analogy with the classical central venous pressure rules to assess a fluid challenge, we hypothesized that an increase in central venous pressure greater than or equal to 5 cm H2O (i.e., 4 mm Hg) during passive leg raising can predict preload unresponsiveness diagnosed by the absence of increase in velocity-time integral of the left ventricular outflow tract greater than or equal to 10% during the test (negative passive leg raising test). Velocity-time integral was measured by transthoracic echocardiography. Central venous pressure and velocity-time integral were measured before and during passive leg raising. Critically ill patients for whom the physician decided to test preload responsiveness by passive leg raising were prospectively included. Fifty-seven set of measurements were performed in 50 patients. Preload unresponsiveness (negative passive leg raising test) was observed in 32 cases. The changes in central venous pressure during passive leg raising did not differ between positive passive leg raising cases (positive passive leg raising test) and negative passive leg raising test cases (3 ± 2 vs 3 ± 2 mm Hg, respectively) and thus did not predict preload unresponsiveness (area under the receiver-operating characteristic curve of 0.59). An increase in central venous pressure greater than or equal to 4 mm Hg during passive leg raising was observed in 10 cases of positive passive leg raising test and in 11 cases of negative passive leg raising test. Taking an increase in central venous pressure greater than or equal to 3 or greater than or equal to 5 mm Hg rather than greater than or equal to 4 mm Hg during passive leg raising did not better allow one to identify negative passive leg raising test. Marked increase in central venous pressure during passive leg raising cannot identify negative passive leg raising test cases and thus preload unresponsiveness. Measurements of cardiac output (or its surrogates) during passive leg raising are, thus, mandatory to appropriately interpret this test.

End-expiratory occlusion test predicts fluid responsiveness in cardiac surgical patients in the operating theatre.

The aim of this study was to evaluate whether a 20-second end-expiratory occlusion (EEO) test can predict fluid responsiveness in cardiac surgery patients in the operating theatre. This prospective study enrolled 75 mechanically ventilated patients undergoing elective coronary artery bypass grafting surgery. Hemodynamic data coupled with transesophageal echocardiography monitoring of the velocity time integral (VTI) and the peak velocity (Vmax) at the left ventricular outflow tract were collected at each step (baseline 1, EEO, baseline 2 and fluid challenge). Patients were divided into fluid responders (increase in VTI ≥15%) and non-responders (increase in VTI <15%) after a fluid challenge (6 mL 0.9% saline per kg, given in 10 minutes). Fluid challenge significantly increased the VTI by more than 15% in 36 (48%) patients (responders). An increase in VTI greater than 5% during the EEO test predicted fluid responsiveness with a sensitivity of 81% and a specificity of 93%. The area under the receiver-operating characteristic curve (AUROC) of ΔVTI-EEO was 0.90 [95% confidence interval (CI): 0.83-0.97]. ΔVmax-EEO was poorly predictive of fluid responsiveness, with an AUC of 0.75 (95% CI: 0.63-0.86). Changes in VTI induced by a 20-second EEO can reliably predict fluid responsiveness in cardiac surgical patients in the operating theatre, whereas the changes in Vmax cannot.

End-expiratory occlusion maneuver to predict fluid responsiveness in the intensive care unit: an echocardiographic study

BackgroundIn mechanically ventilated patients, an increase in cardiac index during an end-expiratory-occlusion test predicts fluid responsiveness. To identify this rapid increase in cardiac index, continuous and instantaneous cardiac index monitoring is necessary, decreasing its feasibility at the bedside. Our study was designed to investigate whether changes in velocity time integral and in peak velocity obtained using transthoracic echocardiography during an end-expiratory-occlusion maneuver could predict fluid responsiveness.MethodsThis single-center, prospective study included 50 mechanically ventilated critically ill patients. Velocity time integral and peak velocity were assessed using transthoracic echocardiography before and at the end of a 12-sec end-expiratory-occlusion maneuver. A third set of measurements was performed after volume expansion (500 mL of saline 0.9% given over 15 minutes). Patients were considered as responders if cardiac output increased by 15% or more after volume expansion.ResultsTwenty-eight patients were responders. At baseline, heart rate, mean arterial pressure, cardiac output, velocity time integral and peak velocity were similar between responders and non-responders. End-expiratory-occlusion maneuver induced a significant increase in velocity time integral both in responders and non-responders, and a significant increase in peak velocity only in responders. A 9% increase in velocity time integral induced by the end-expiratory-occlusion maneuver predicted fluid responsiveness with sensitivity of 89% (95% CI 72% to 98%) and specificity of 95% (95% CI 77% to 100%). An 8.5% increase in peak velocity induced by the end-expiratory-occlusion maneuver predicted fluid responsiveness with sensitivity of 64% (95% CI 44% to 81%) and specificity of 77% (95% CI 55% to 92%). The area under the receiver operating curve generated for changes in velocity time integral was significantly higher than the one generated for changes in peak velocity (0.96 ± 0.03 versus 0.70 ± 0.07, respectively, P = 0.0004 for both). The gray zone ranged between 6 and 10% (20% of the patients) for changes in velocity time integral and between 1 and 13% (62% of the patients) for changes in peak velocity.ConclusionsIn mechanically ventilated and sedated patients in the neuro Intensive Care Unit, changes in velocity time integral during a 12-sec end-expiratory-occlusion maneuver were able to predict fluid responsiveness and perform better than changes in peak velocity.

Variabilité respiratoire et déplétion neuronale sérotoninergique du tronc cérébral dans un modèle murin transgénique d’atrophie multisystématisée

Pulse pressure variation (PPV) is not reliable in predicting preload responsiveness in patients receiving mechanical with spontaneous breathing (SB) activity. We hypothesised that an increase in PPV after a tidal volume (VT) challenge (TVC) or a decrease in PPV during passive leg raising (PLR) can predict preload responsiveness in such cases.This prospective observational study was performed in two ICUs and included patients receiving mechanical ventilation with SB, for whom the treating physician decided to test preload responsiveness. Transthoracic echocardiography was used to measure the velocity–time integral (VTI) of the left ventricular outflow tract. Patients exhibiting an increase in VTI ≥12% during PLR were defined as PLR+ patients (or preload responders). Then, a TVC was performed by increasing VT by 2 ml kg−1 predicted body weight (PBW) for 1 min. PPV was recorded at each step.Fifty-four patients (Simplified Acute Physiology Score II: 60 (25) ventilated with a VT of 6.5 (0.8) ml kg−1 PBW, were included. Twenty-two patients were PLR+. The absolute decrease in PPV during PLR and the absolute increase in PPV during TVC discriminated between PLR+ and PLR– patients with area under the receiver operating characteristic (AUROC) curve of 0.78 and 0.73, respectively, and cut-off values of –1% and +2%, respectively. Those AUROC curve values were similar but were significantly different from that of baseline PPV (0.61).In patients undergoing mechanical ventilation with SB activity, PPV does not predict preload responsiveness. However, the decrease in PPV during PLR and the increase in PPV during a TVC help discriminate preload responders from non-responders with moderate accuracy.NCT04369027 (ClinicalTrials.gov).

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