End-expiratory occlusion test predicts fluid responsiveness in cardiac surgical patients in the operating theatre.
ABSTRACT: Background: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. Methods: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). Results: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 ?VTI-EEO was 0.90 [95% confidence interval (CI): 0.83-0.97]. ?Vmax-EEO was poorly predictive of fluid responsiveness, with an AUC of 0.75 (95% CI: 0.63-0.86). Conclusions: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.
Project description:BACKGROUND:Mini-fluid challenge is a well tested and effective tool to predict fluid responsiveness under various clinical conditions. However, mini-fluid challenge has never been tested in patients with end-stage liver disease. This study investigated whether infusion of 150?ml albumin 5% can predict fluid responsiveness in cirrhotic patients following liver transplant. METHODS:Fifty patients receiving living donor liver transplant were included in the analysis. Mini-fluid challenge composed of 150?ml of albumin 5% administered over 1?min in three consecutive 50-ml fluid boluses. An additional 350?ml was then infused at a constant rate over 15?min (for a total of 500?ml). Stroke volume (SV) was measured as the product of the subaortic velocity time integral (VTI) and left ventricular outflow tract (LVOT) area. Fluid responsiveness was defined as an increase in SV by ?15% after the infusion. RESULTS:Fifty patients were enrolled in the study. Fourteen patients were classified with Child A, 15 patients with Child B, and 21 patients with Child C cirrhosis. Thirty four patients were fluid responders and 16 patients were fluid non-responders. After 150?ml of albumin 5%, the SV increased significantly in our cohort. The area under receiver operating curve (AUROC) was 0.7 (95% confidence interval [CI] 0.5-0.8, P =?0.005). In subgroup analysis, the SV increased significantly after mini fluid challenge in the Child A group (P =?0.017) but not Child B or C groups (P =?0.3 and 0.29, respectively). The AUROC for mini-fluid challenge in the Child A group was 0.86 (95% confidence interval [CI] 0.6-0.9, P =?0.0004), while mini-fluid challenge failed to discriminate between responders and non-responders in Child B and C groups. CONCLUSION:A mini-fluid challenge of 150?ml albumin 5% can predict fluid responsiveness in liver transplant patients with fair sensitivity and specifiicty. Subgroup analyis revealed that minifluid challenge can predict fluid responsiveness in patients with Child A cirrhosis but not patients with Child B or C cirrhosis. TRIAL REGISTRATION:NCT03396159 . (Prospective registered). Initial registration date was 10/01/2018.
Project description:BACKGROUND:Fluid challenge (FC) is one of the most common practices in Intensive Care Unit (ICU). The present study aimed to evaluate whether echocardiographic assessment of the response to FC at the end of the infusion or 20?min later could affect the results of the FC. METHODS:This is a prospective, observational, multicenter study including all ICU patients in septic shock requiring a FC of 500?mL crystalloids over 10?min. Fluid responsiveness was defined as a >?15% increase in stroke volume (SV) assessed by velocity-time integral (VTI) measurements at baseline (T0), at the end of FC (T10), then 10 (T20) and 20?min (T30) after the end of FC. RESULTS:From May 20, 2014, to January 7, 2016, a total of 143 patients were enrolled in 11 French ICUs (mean age 64?±?14?years, median IGS II 53 [43-63], median SOFA score 10 [8-12]). Among the 76/143 (53%) patient responders to FC at T10, 37 patients were transient responders (TR), i.e., became non-responders (NR) at T30 (49%, 95%CI?=?[37-60]), and 39 (51%, 95%CI?=?[38-62]) patients were persistent responders (PR), i.e., remained responders at T30. Among the 67 NR at T10, 4 became responders at T30, (6%, 95%CI?=?[1.9-15.3]). In the subgroup analysis, no statistical difference in hemodynamic and echocardiographic parameters was found between groups. CONCLUSIONS:This study shows that 51.3% of initial responders have a persistent response to fluid 30?min after the beginning of fluid infusion and only 41.3% have a transient response highlighting that fluid responsiveness is time dependent. TRIAL REGISTRATION:ClinicalTrials.gov , NCT02116413 . Registered on April 16, 2014.
Project description:To evaluate the efficacy of using internal jugular vein variability (IJVV) as an index of fluid responsiveness in mechanically ventilated patients after cardiac surgery.Seventy patients were assessed after cardiac surgery. Hemodynamic data coupled with ultrasound evaluation of IJVV and inferior vena cava variability (IVCV) were collected and calculated at baseline, after a passive leg raising (PLR) test and after a 500-ml fluid challenge. Patients were divided into volume responders (increase in stroke volume ≥ 15%) and non-responders (increase in stroke volume < 15%). We compared the differences in measured variables between responders and non-responders and tested the ability of the indices to predict fluid responsiveness.Thirty-five (50%) patients were fluid responders. Responders presented higher IJVV, IVCV and stroke volume variation (SVV) compared with non-responders at baseline (P < 0.05). The relationship between IJVV and SVV was moderately correlated (r = 0.51, P < 0.01). The areas under the receiver operating characteristic (ROC) curves for predicting fluid responsiveness were 0.88 (CI 0.78-0.94) for IJVV compared with 0.83 (CI 0.72-0.91), 0.97 (CI 0.89-0.99), 0.91 (CI 0.82-0.97) for IVCV, SVV, and the increase in stroke volume in response to a PLR test, respectively.Ultrasound-derived IJVV is an accurate, easily acquired noninvasive parameter of fluid responsiveness in mechanically ventilated postoperative cardiac surgery patients, with a performance similar to that of IVCV.
Project description:OBJECTIVES:Adequate assessment of fluid responsiveness in shock necessitates correct interpretation of hemodynamic changes induced by preload challenge. This study evaluates the accuracy of point-of-care Doppler ultrasound assessment of the change in carotid corrected flow time induced by a passive leg raise maneuver as a predictor of fluid responsiveness. Noninvasive cardiac output monitoring (NICOM, Cheetah Medical, Newton Center, MA) system based on a bioreactance method was used. DESIGN:Prospective, noninterventional study. SETTING:ICU at a large academic center. PATIENTS:Patients with new, undifferentiated shock, and vasopressor requirements despite fluid resuscitation were included. Patients with significant cardiac disease and conditions that precluded adequate passive leg raising were excluded. INTERVENTIONS:Carotid corrected flow time was measured via ultrasound before and after a passive leg raise maneuver. Predicted fluid responsiveness was defined as greater than 10% increase in stroke volume on noninvasive cardiac output monitoring following passive leg raise. Images and measurements were reanalyzed by a second, blinded physician. The accuracy of change in carotid corrected flow time to predict fluid responsiveness was evaluated using receiver operating characteristic analysis. MEASUREMENTS AND MAIN RESULTS:Seventy-seven subjects were enrolled with 54 (70.1%) classified as fluid responders by noninvasive cardiac output monitoring. The average change in carotid corrected flow time after passive leg raise for fluid responders was 14.1?±?18.7?ms versus -4.0?±?8?ms for nonresponders (p < 0.001). Receiver operating characteristic analysis demonstrated that change in carotid corrected flow time is an accurate predictor of fluid responsiveness status (area under the curve, 0.88; 95% CI, 0.80-0.96) and a 7?ms increase in carotid corrected flow time post passive leg raise was shown to have a 97% positive predictive value and 82% accuracy in detecting fluid responsiveness using noninvasive cardiac output monitoring as a reference standard. Mechanical ventilation, respiratory rate, and high positive end-expiratory pressure had no significant impact on test performance. Post hoc blinded evaluation of bedside acquired measurements demonstrated agreement between evaluators. CONCLUSIONS:Change in carotid corrected flow time can predict fluid responsiveness status after a passive leg raise maneuver. Using point-of-care ultrasound to assess change in carotid corrected flow time is an acceptable and reproducible method for noninvasive identification of fluid responsiveness in critically ill patients with undifferentiated shock.
Project description:INTRODUCTION: The aim of the study was to evaluate the ability of different static and dynamic measurements of preload to predict fluid responsiveness in patients with spontaneous respiratory movements. METHODS: The subjects were 21 critically ill patients with spontaneous breathing movements receiving mechanical ventilation with pressure support mode (n = 9) or breathing through a face mask (n = 12), and who required a fluid challenge. Complete hemodynamic measurements, including pulmonary artery occluded pressure (PAOP), right atrial pressure (RAP), pulse pressure variation (DeltaPP) and inspiratory variation in RAP were obtained before and after fluid challenge. Fluid challenge consisted of boluses of either crystalloid or colloid until cardiac output reached a plateau. Receiver operating characteristics (ROC) curve analysis was used to evaluate the predictive value of the indices to the response to fluids, as defined by an increase in cardiac index of 15% or more. RESULTS: Cardiac index increased from 3.0 (2.3 to 3.5) to 3.5 (3.0 to 3.9) l minute-1 m-2 (medians and 25th and 75th centiles), p < 0.05. At baseline, DeltaPP varied between 0% and 49%. There were no significant differences in DeltaPP, PAOP, RAP and inspiratory variation in RAP between fluid responders and non-responders. Fluid responsiveness was predicted better with static indices (ROC curve area +/- SD: 0.73 +/- 0.13 for PAOP, p < 0.05 vs DeltaPP and 0.69 +/- 0.12 for RAP, p = 0.054 compared with DeltaPP) than with dynamic indices of preload (0.40 +/- 0.13 for DeltaPP and 0.53 +/- 0.13 for inspiratory changes in RAP, p not significant compared with DeltaPP). CONCLUSION: In patients with spontaneous respiratory movements, DeltaPP and inspiratory changes in RAP failed to predict the response to volume expansion.
Project description:BACKGROUND:The reliability of pulse pressure variation (PPV) and stroke volume variation (SVV) is controversial under pneumoperitoneum. In addition, the usefulness of these indices is being called into question with the increasing adoption of lung-protective ventilation using low tidal volume (VT) in surgical patients. A recent study indicated that changes in PPV or SVV obtained by transiently increasing VT (VT challenge) accurately predicted fluid responsiveness even in critically ill patients receiving low VT. We evaluated whether the changes in PPV and SVV induced by a VT challenge predicted fluid responsiveness during pneumoperitoneum. METHODS:We performed an interventional prospective study in patients undergoing robot-assisted laparoscopic surgery in the Trendelenburg position under lung-protective ventilation. PPV, SVV, and the stroke volume index (SVI) were measured at a VT of 6?mL/kg and 3?min after increasing the VT to 8?mL/kg. The VT was reduced to 6?mL/kg, and measurements were performed before and 5?min after volume expansion (infusing 6% hydroxyethyl starch 6?ml/kg over 10?min). Fluid responsiveness was defined as ?15% increase in the SVI. RESULTS:Twenty-four of the 38 patients enrolled in the study were responders. In the receiver operating characteristic curve analysis, an increase in PPV?>?1% after the VT challenge showed excellent predictive capability for fluid responsiveness, with an area under the curve (AUC) of 0.95 [95% confidence interval (CI), 0.83-0.99, P <?0.0001; sensitivity 92%, specificity 86%]. An increase in SVV?>?2% after the VT challenge predicted fluid responsiveness, but showed only fair predictive capability, with an AUC of 0.76 (95% CI, 0.60-0.89, P <?0.0006; sensitivity 46%, specificity 100%). The augmented values of PPV and SVV following VT challenge also showed the improved predictability of fluid responsiveness compared to PPV and SVV values (as measured by VT) of 6?ml/kg. CONCLUSIONS:The change in PPV following the VT challenge has excellent reliability in predicting fluid responsiveness in our surgical population. The change in SVV and augmented values of PPV and SVV following this test are also reliable. TRIAL REGISTRATION:This trial was registered with Clinicaltrials.gov, NCT03467711 , 10th March 2018.
Project description:Patients who increase stoke volume or cardiac index more than 10 or 15% after a fluid challenge are usually considered fluid responders. Assessment of fluid responsiveness prior to volume expansion is critical to avoid fluid overload, which has been associated with poor outcomes. Maneuvers to assess fluid responsiveness are well established in mechanically ventilated patients; however, few studies evaluated maneuvers to predict fluid responsiveness in spontaneously breathing patients. Our objective was to perform a systematic review of literature addressing the available methods to assess fluid responsiveness in spontaneously breathing patients. Studies were identified through electronic literature search of PubMed from 01/08/2009 to 01/08/2016 by two independent authors. No restrictions on language were adopted. Quality of included studies was evaluated with Quality Assessment of Diagnostic Accuracy Studies tool. Our search strategy identified 537 studies, and 9 studies were added through manual search. Of those, 15 studies (12 intensive care unit patients; 1 emergency department patients; 1 intensive care unit and emergency department patients; 1 operating room) were included in this analysis. In total, 649 spontaneously breathing patients were assessed for fluid responsiveness. Of those, 340 (52%) were deemed fluid responsive. Pulse pressure variation during the Valsalva maneuver (?PPV) of 52% (AUC ± SD: 0.98 ± 0.03) and passive leg raising-induced change in stroke volume (?SV-PLR) > 13% (AUC ± SD: 0.96 ± 0.03) showed the highest accuracy to predict fluid responsiveness in spontaneously breathing patients. Our systematic review indicates that regardless of the limitations of each maneuver, fluid responsiveness can be assessed in spontaneously breathing patients. Further well-designed studies, with adequate simple size and power, are necessary to confirm the real accuracy of the different methods used to assess fluid responsiveness in this population of patients.
Project description:PURPOSE:The pressure recording analytical method (PRAM) monitor is a non-invasive pulse contour cardiac output (CO) device that cannot be considered interchangeable with the gold standard for CO estimation. It, however, generates additional hemodynamic indices that need to be evaluated. Our objective was to investigate the performance of a multiparametric predictive score based on a combination of several parameters generated by the PRAM monitor to predict fluid responsiveness. METHODS:Secondary analysis of a prospective observational study from April 2016 to December 2017 in two French teaching hospitals. We included critically ill patients who were monitored by esophageal Doppler monitoring and an invasive arterial line, and received a 250-500 mL crystalloid fluid challenge. The main outcome measure was the predictive score discrimination evaluated by the area under the receiver operating characteristics curve. RESULTS:The three baseline PRAM-derived parameters associated with fluid responsiveness in univariate analysis were pulse pressure variation, cardiac cycle efficiency, and arterial elastance (P < 0.01, P = 0.03, and P < 0.01, respectively). The median [interquartile range] predictive score, calculated after discretization of these parameters according to their optimal threshold value was 3 [2-3] in fluid responders and 1 [1-2] in fluid non-responders, respectively (P < 0.001). The area under the curve of the predictive score was 0.807 (95% confidence interval, 0.662 to 0.909; P < 0.001). CONCLUSION:A multiparametric score combining three parameters generated by the PRAM monitor can predict fluid responsiveness with good positive and negative predictive values in intensive care unit patients.
Project description:BACKGROUND:In critically ill patients, changes in the velocity-time integral (VTI) of the left ventricular outflow tract, measured by transthoracic echocardiography (TTE), are often used to non-invasively assess the response to fluid administration or for performing tests assessing fluid responsiveness. However, the precision of TTE measurements has not yet been investigated in such patients. First, we aimed at assessing how many measurements should be averaged within one TTE examination to reach a sufficient precision for various variables. Second, we aimed at identifying the least significant change (LSC) of these variables between successive TTE examinations. METHODS:We prospectively included 100 haemodynamically stable patients in whom TTE examination was planned. Three TTE examinations were performed, the first and the third by one operator and the second by another one. We calculated the precision and LSC (1) within one examination depending on the number of averaged measurements and (2) between measurements performed in two successive examinations. RESULTS:In patients in sinus rhythm, averaging three measurements within an examination was enough for obtaining an acceptable precision (interquartile range highest value < 10%) for VTI. In patients with atrial fibrillation, averaging five measurements was necessary. The precision of some other common TTE variables depending on the number of measurements is provided. Between two successive examinations performed by the same operator, the LSC was 11 [5-18]% for VTI. If two operators performed the examinations, the LSC for VTI significantly increased to 14 [8-26]%. The LSC between two examinations for other TTE variables is also provided. CONCLUSIONS:Averaging three measurements within one TTE examination is enough for obtaining precise measurements for VTI in patients in sinus rhythm but not in patients with atrial fibrillation. Between two TTE examinations performed by the same operator, the LSC of VTI is compatible with the assessment of the effects of a 500-mL fluid infusion but is not precise enough for assessing the effects of some tests predicting preload responsiveness.
Project description:Background:The aim of this study is to examine whether plasma N-terminal pro-B-type natriuretic peptide (NT-proBNP) concentration could predict fluid responsiveness in septic shock patients following fluid challenge (FC). Methods:We reviewed prospectively collected data from 79 septic shock patients who received invasive cardiac output (CO) monitoring following a 500 mL FC. Haemodynamics were recorded, and blood sampling for NT-proBNP values was performed. Patients were divided into responders and non-responders according to fluid responsiveness, which was defined as cardiac index (CI) increase ?10% induced by FC. The NT-proBNP and the CI changes were analysed using Pearson correlation. The area under the curve (AUC) for NT-proBNP was used to test its ability to distinguish responders and non-responders. Subgroup analyses were also explored. Results:Among 79 patients, there were 55 responders. High NT-proBNP values were common in the study cohort. Baseline NT-proBNP values were comparable between responders and non-responders. In general, NT-proBNP values were not significantly correlated with CI changes after FC (r=-0.104, P=0.361). Similarly, the NT-proBNP baseline values could not identify responders to FC with an AUC of 0.508 (95% confidence interval, 0.369-0.647). This result was further confirmed in the subgroup analyses. Conclusions:Baseline NT-proBNP concentration value may not serve as an indicator of fluid responsiveness in patients with septic shock and should not be an indicator to withhold fluid loading.