Fluid Responsiveness In Septic Patients Research Articles

End-tidal carbon dioxide's change to fluid challenge versus internal jugular vein dispensability index for predicting fluid responsiveness in septic patients: A prospective, observational study.

The prediction of fluid responsiveness is crucial for the fluid management of septic shock patients. This prospective, observational study was conducted to compare end-tidal carbon dioxide (ETCO2) change due to fluid challenge (FC-induced ΔETCO2) versus internal jugular vein distensibility index (IJVDI) as predictors of fluid responsiveness in such patients. Septic hypoperfused mechanically ventilated patients were classified as fluid responders (Rs) and non-responders (NRs) according to the improvement of left ventricular outflow tract-velocity time integral (ΔLVOT-VTI) after fluid challenge (FC). The receiver operating characteristic (ROC) curves of FC-induced ΔETCO2, pre-(FC) IJVDI and their combination for prediction of fluid responsiveness were compared to that of ΔLVOT-VTI% as a gold standard. Of 140 patients who completed the study, 51 (36.4%) patients were classified as Rs and 89 (63.6%) patients as NRs. With regard to the prediction of fluid responsiveness, no significant difference (P. 0. 384) was found between the diagnostic accuracy of FC-induced ΔETCO2 >2 mmHg (area under the ROC curve [AUC] 0.908, P < 0.001) and that of pre-(FC) IJVDI >18% (AUC 0.938, P < 0.001), but a prediction model combining both markers, ΔETCO2 ≥3 mmHg and IJVDI ≥16%, achieved significantly higher accuracy (AUC 0.982, P < 0.001) than each independent one (P < 0.05). Under stable ventilatory and metabolic conditions, the predictivity of FC-induced ΔETCO2 >2 mmHg can be comparable to that of pre-(FC) IJVDI >18%. A predictive model combining both FC-induced ΔETCO2 ≥3 mmHg and IJVDI ≥16% can provide higher accuracy than that recorded for each one independently.

Accuracy of changing rate of left ventricular outflow tract velocity time integral in predicting fluid responsiveness in septic patients

Objective To evaluate the accuracy of changing rate of the left ventricular outflow tract velocity time integral (△VTI) in predicting fluid responsiveness in septic patients. Methods Twenty patients diagnosed with sepsis or septic shock and received mechanical ventilation, aged more than or equal to 18 yr, in whom the ventilation mode was SIMV plus VC, were enrolled in this study.The left ventricular outflow tract VTI, stroke volume (SV) and cardiac output (CO) were measured using ultrasound.Sodium potassium magnesium calcium and glucose injection 100 ml was intravenously infused over 1 min, ultrasound measurement was completed within 1 min, and then Sodium potassium magnesium calcium and glucose injection 400 ml was intravenously infused over 14 min.Fluid responsiveness was defined as increase in SV or CO more than 15% after infusion of 500 ml colloid solution, and then the patients were divided into responsiveness group and non-responsiveness group.△VTI, △SV and △CO were calculated after fluid replacement with 100 ml solution.The receiver operating characteristic curve was used to assess the accuracy of △VTI, △SV and △CO in predicting fluid responsiveness. Results The areas under the receiver operating characteristic curve of △VTI, △SV and △CO were 0.95, 0.91 and 0.88, respectively.When △VTI≥10% was used as the cut-off point, the sensitivity and specificity of △VTI in predicting fluid responsiveness was 90% and 80%, respectively. Conclusion △VTI can accurately predict the fluid responsiveness in septic patients. Key words: Blood flow velocity; Sepsis; Vascular capacitance

Accuracy of different methods in predicting fluid responsiveness in septic patients: a comparison between ultrasound, PiCCO and traditional methods

Objective To compare the accuracy of ultrasound, pulse indicator continuous cardiac output monitoring (PiCCO) and traditional methods in predicting fluid responsiveness in septic patients. Methods Forty-six septic patients of both sexes, aged 18-72 yr, requiring mechanical ventilation treatment in the intensive care unit, were enrolled in the study.Venous blood samples were collected for determination of plasma B-type natriuretic peptide (BNP) concentrations by chemiluminescence assay, and central venous pressure (CVP) was recorded.Stroke volume variation (SVVTTE), distensibility index of inferior vena cava (dIVC) and velocity time integral changes of aortic blood flow (ΔVTI) were measured by ultrasound method.SVVPiCCO and global end-diastolic volume index (GEDVI) were measured by PiCCO method.The patients were divided into negative fluid responsiveness group and positive fluid responsiveness group according to the fluid responsiveness after volume expansion.The receiver operating characteristic curves of the parameters mentioned above in predicting fluid responsiveness were drawn.A consistency check for dIVC, ΔVTI and SVVPiCCO thresholds was conducted by using Kappa statistics.The agreement between SVVTTE and SVVPiCCO was analyzed by the Bland-Altman analysis. Results There were 24 patients in positive fluid responsiveness group and 22 patients in negative fluid responsiveness group.Compared with negative fluid responsiveness group, the plasma BNP concentration, CVP and GEDVI were significantly decreased, and SVVPiCCO, SVVTTE, dIVC and ΔVTI were increased before volume expansion in positive fluid responsiveness group (P<0.05). The area under the curve (95% confidence interval), sensitivity and specificity of the plasma BNP concentration were 0.894 (0.807-0.981), 81.8% and 79.2%, respectively, of CVP 0.859 (0.752-0.965), 81.8% and 79.2%, respectively, of GEDVI 0.772 (0.628-0.915), 72.7% and 75.0%, respectively, of SVVPiCCO 0.965 (0.922-1.008), 95.8% and 81.8%, respectively, of SVVTTE 0.940 (0.874-1.006), 91.7% and 86.4%, respectively, of dIVC 0.964 (0.920-1.008), 83.3% and 95.5%, respectively, and of ΔVTI 0.958 (0.909-1.008), 87.5% and 90.9%, respectively.The Kappa value for dIVC threshold and SVVPiCCO threshold was 0.826, and for ΔVTI threshold and SVVPiCCO threshold was 0.743 (P<0.01). The mean deviation of SVVTTE and SVVPiCCO was 0.209, 95% confidence interval (-2.967-3.385)%, and the limit of agreement (-2.46-2.62)%(P<0.05). Conclusion Ultrasound and PiCCO methods can accurately predict fluid responsiveness, have a good agreement and are superior to the traditional method in septic patients. Key words: Echocardiography; Monitoring, physiologic; Vascular capacitance; Sepsis

The comparison of stroke volume variation with central venous pressure in predicting fluid responsiveness in septic patients with acute circulatory failure.

Purpose:The present study was designed to investigate the efficacy of stroke volume variation (SVV) in predicting fluid responsiveness and compare it to traditional measures of volume status assessment like central venous pressure (CVP).Methods:Forty-five mechanically ventilated patients in sepsis with acute circulatory failure. Patients were not included when they had atrial fibrillation, other severe arrhythmias, permanent pacemaker, or needed mechanical cardiac support. Furthermore, excluded were patients with hypoxemia and a CVP >12. Patients received volume expansion in the form of 500 ml of 6% hydroxyethyl starch.Results:The volume expansion-induced increase in cardiac index (CI) was >15% in 29 patients (labeled responders) and <15% in 16 patients (labeled nonresponders). Before volume expansion, SVV was higher in responders than in nonresponders. Receiver operating characteristic curves analysis showed that SVV was a more accurate indicator of fluid responsiveness than CVP. Before volume expansion, an SVV value of 13% allowed discrimination between responders and nonresponders with a sensitivity of 78% and a specificity of 89%. Volume expansion-induced changes in CI weakly and positively correlated with SVV before volume expansion. Volume expansion decreased SVV from 18.86 ± 4.35 to 7.57 ± 1.80 and volume expansion-induced changes in SVV moderately correlated with volume expansion-induced changes in CI.Conclusions:When predicting fluid responsiveness in mechanically ventilated patients in septic shock, SVV is more effective than CVP. Nevertheless, the overall correlation of baseline SVV with increases in CI remains poor. Trends in SVV, as reflected by decreases with volume replacement, seem to correlate much better with increases in CI.

Jugular vein distensibility predicts fluid responsiveness in septic patients.

IntroductionThe purpose of the study was to verify the efficacy of using internal jugular vein (IJV) size and distensibility as a reliable index of fluid responsiveness in mechanically ventilated patients with sepsis.MethodsHemodynamic data of mechanically ventilated patients with sepsis were collected through a radial arterial indwelling catheter connected to continuous hemodynamic monitoring system (Most Care®, Vytech Health, Padova, Italy), including cardiac index (CI) (L/min/M2), heart rate (beats/min), mean arterial pressure (MAP) (mmHg), central venous pressure (CVP) (mmHg) and arterial pulse pressure variation (PPV), coupled with ultrasound evaluation of IJV distensibility (%), defined as a ratio of the difference between IJV maximal antero-posterior diameter during inspiration and minimum expiratory diameter to minimum expiratory diameter x100. Patients were retrospectively divided into two groups; fluid responders (R), if CI increase of more than or equal to 15% after a 7 ml/kg crystalloid infusion, and non-responders (NR) if CI increased more than 15%. We compared differences in measured variables between R and NR groups and calculated receiver-operator-characteristic (ROC) curves of optimal IJV distensibility and PPV sensitivity and specificity to predicting R. We also calculated a combined inferior vena cava distensibility-PPV ROC curve to predict R.ResultsWe enrolled 50 patients, of these, 30 were R. Responders presented higher IJV distensibility and PPV before fluid challenge than NR (P <0.05). An IJV distensibility more than 18% prior to volume challenge had an 80% sensitivity and 85% specificity to predict R. Pairwise comparison between IJV distensibility and PPV ROC curves revealed similar ROC area under the curve results. Interestingly, combining IJV distensibility more than 9.7% and PPV more than 12% predicted fluid responsiveness with a sensitivity of 100% and specificity of 95%.ConclusionIJV distensibility is an accurate, easily acquired non-invasive parameter of fluid responsiveness in mechanically ventilated septic patients with performance similar to PPV. The combined use of IJV distensibility with left-sided indexes of fluid responsiveness improves their predictive value.Electronic supplementary materialThe online version of this article (doi:10.1186/s13054-014-0647-1) contains supplementary material, which is available to authorized users.

Predictive value of pulse pressure variation for fluid responsiveness in septic patients using lung-protective ventilation strategies

BackgroundThe applicability of pulse pressure variation (ΔPP) to predict fluid responsiveness using lung-protective ventilation strategies is uncertain in clinical practice. We designed this study to evaluate the accuracy of this parameter in predicting the fluid responsiveness of septic patients ventilated with low tidal volumes (TV) (6 ml kg−1).MethodsForty patients after the resuscitation phase of severe sepsis and septic shock who were mechanically ventilated with 6 ml kg−1 were included. The ΔPP was obtained automatically at baseline and after a standardized fluid challenge (7 ml kg−1). Patients whose cardiac output increased by more than 15% were considered fluid responders. The predictive values of ΔPP and static variables [right atrial pressure (RAP) and pulmonary artery occlusion pressure (PAOP)] were evaluated through a receiver operating characteristic (ROC) curve analysis.ResultsThirty-four patients had characteristics consistent with acute lung injury or acute respiratory distress syndrome and were ventilated with high levels of PEEP [median (inter-quartile range) 10.0 (10.0–13.5)]. Nineteen patients were considered fluid responders. The RAP and PAOP significantly increased, and ΔPP significantly decreased after volume expansion. The ΔPP performance [ROC curve area: 0.91 (0.82–1.0)] was better than that of the RAP [ROC curve area: 0.73 (0.59–0.90)] and pulmonary artery occlusion pressure [ROC curve area: 0.58 (0.40–0.76)]. The ROC curve analysis revealed that the best cut-off for ΔPP was 6.5%, with a sensitivity of 0.89, specificity of 0.90, positive predictive value of 0.89, and negative predictive value of 0.90.ConclusionsAutomatized ΔPP accurately predicted fluid responsiveness in septic patients ventilated with low TV.

Case Scenario

Case Scenario

Cardiac filling pressures are not appropriate to predict hemodynamic response to volume challenge*

Values of central venous pressure of 8-12 mm Hg and of pulmonary artery occlusion pressure of 12-15 mm Hg have been proposed as volume resuscitation targets in recent international guidelines on management of severe sepsis. By analyzing a large number of volume challenges, our aim was to test the significance of the recommended target values in terms of prediction of volume responsiveness. Retrospective study. A 24-bed medical intensive care unit. All consecutive septic patients monitored with a pulmonary artery catheter who underwent a volume challenge between 2001 and 2004. None. A total of 150 volume challenges in 96 patients were reviewed. In 65 instances, the volume challenge resulted in an increase in cardiac index of > or =15% (responders). The pre-infusion central venous pressure was similar in responders and nonresponders (8 +/- 4 vs. 9 +/- 4 mm Hg). The pre-infusion pulmonary artery occlusion pressure was slightly lower in responders (10 +/- 4 vs. 11 +/- 4 mm Hg, p < .05). However, the significance of pulmonary artery occlusion pressure to predict fluid responsiveness was poor and similar to that of central venous pressure, as indicated by low values of areas under the receiver operating characteristic curves (0.58 and 0.63, respectively). A central venous pressure of <8 mm Hg and a pulmonary artery occlusion pressure of <12 mm Hg predicted volume responsiveness with a positive predictive value of only 47% and 54%, respectively. With the knowledge of a low stroke volume index (<30 mL.m), their positive predictive values were still unsatisfactory: 61% and 69%, respectively. When the combination of central venous pressure and pulmonary artery occlusion pressure was considered instead of either pressure alone, the degree of prediction of volume responsiveness was not improved. Our study demonstrates that cardiac filling pressures are poor predictors of fluid responsiveness in septic patients. Therefore, their use as targets for volume resuscitation must be discouraged, at least after the early phase of sepsis has concluded.

Respiratory changes in inferior vena cava diameter are helpful in predicting fluid responsiveness in ventilated septic patients

To evaluate the extent to which respiratory changes in inferior vena cava (IVC) diameter can be used to predict fluid responsiveness. Prospective clinical study. Hospital intensive care unit. Twenty-three patients with acute circulatory failure related to sepsis and mechanically ventilated because of an acute lung injury. Inferior vena cava diameter (D) at end-expiration (Dmin) and at end-inspiration (Dmax) was measured by echocardiography using a subcostal approach. The distensibility index of the IVC (dIVC) was calculated as the ratio of Dmax - Dmin / Dmin, and expressed as a percentage. The Doppler technique was applied in the pulmonary artery trunk to determine cardiac index (CI). Measurements were performed at baseline and after a 7 ml/kg volume expansion using a plasma expander. Patients were separated into responders (increase in CI > or =15%) and non-responders (increase in CI <15%). Using a threshold dIVC of 18%, responders and non-responders were discriminated with 90% sensitivity and 90% specificity. A strong relation (r = 0.9) was observed between dIVC at baseline and the CI increase following blood volume expansion. Baseline central venous pressure did not accurately predict fluid responsiveness. Our study suggests that respiratory change in IVC diameter is an accurate predictor of fluid responsiveness in septic patients.

Relation between respiratory changes in arterial pulse pressure and fluid responsiveness in septic patients with acute circulatory failure.

In mechanically ventilated patients with acute circulatory failure related to sepsis, we investigated whether the respiratory changes in arterial pressure could be related to the effects of volume expansion (VE) on cardiac index (CI). Forty patients instrumented with indwelling systemic and pulmonary artery catheters were studied before and after VE. Maximal and minimal values of pulse pressure (Pp(max) and Pp(min)) and systolic pressure (Ps(max) and Ps(min)) were determined over one respiratory cycle. The respiratory changes in pulse pressure (DeltaPp) were calculated as the difference between Pp(max) and Pp(min) divided by the mean of the two values and were expressed as a percentage. The respiratory changes in systolic pressure (DeltaPs) were calculated using a similar formula. The VE-induced increase in CI was >/= 15% in 16 patients (responders) and < 15% in 24 patients (nonresponders). Before VE, DeltaPp (24 +/- 9 versus 7 +/- 3%, p < 0.001) and DeltaPs (15 +/- 5 versus 6 +/- 3%, p < 0.001) were higher in responders than in nonresponders. Receiver operating characteristic (ROC) curves analysis showed that DeltaPp was a more accurate indicator of fluid responsiveness than DeltaPs. Before VE, a DeltaPp value of 13% allowed discrimination between responders and nonresponders with a sensitivity of 94% and a specificity of 96%. VE-induced changes in CI closely correlated with DeltaPp before volume expansion (r(2) = 0. 85, p < 0.001). VE decreased DeltaPp from 14 +/- 10 to 7 +/- 5% (p < 0.001) and VE-induced changes in DeltaPp correlated with VE-induced changes in CI (r(2) = 0.72, p < 0.001). It was concluded that in mechanically ventilated patients with acute circulatory failure related to sepsis, analysis of DeltaPp is a simple method for predicting and assessing the hemodynamic effects of VE, and that DeltaPp is a more reliable indicator of fluid responsiveness than DeltaPs.