Predict Volume Responsiveness Research Articles

Carotid Flow Time Compared with Invasive Monitoring as a Predictor of Volume Responsiveness in ICU patients.

Objectives: Identifying patients who will have an increase in their cardiac output from volume administration is difficult to identify. We propose the use of carotid flow time, which is a non-invasive means to determine if a patient is volume responsive. Methods: Patients admitted to a critical care unit with a pulmonary artery catheter in place were enrolled. We perform a carotid flow time and pulmonary artery catheter measurement of cardiac output pre and post-passive leg raise and comparing the two. An increase of 10% change in the pre- vs. post-passive leg raise measurement would be indicative of a patient who is volume responsive. Results: We identified 8 patients who were volume responsive as determined by the gold standard pulmonary artery catheter. The sensitivity 87.5% and specificity 90.9%. Pearson correlation coefficient between PA-CO measurements and CFT was r=0.8316, indicative of strong correlation between the two measurements. Conclusion: In our patient sample of critically ill patients with pulmonary artery catheters, we found a strong correlation between corrected carotid flow times and cardiac output measurements from pulmonary artery catheters.

Respiratory variation in the internal jugular vein does not predict fluid responsiveness in the prone position during adolescent idiopathic scoliosis surgery: a prospective cohort study

BackgroundRespiratory variation in the internal jugular vein (IJVV) has not shown promising results in predicting volume responsiveness in ventilated patients with low tidal volume (Vt) in prone position. We aimed to determine whether the baseline respiratory variation in the IJVV value measured by ultrasound might predict fluid responsiveness in patients with adolescent idiopathic scoliosis (AIS) undergoing posterior spinal fusion (PSF) with low Vt.MethodsAccording to the fluid responsiveness results, the included patients were divided into two groups: those who responded to volume expansion, denoted the responder group, and those who did not respond, denoted the non-responder group. The primary outcome was determination of the value of baseline IJVV in predicting fluid responsiveness (≥15% increases in stroke volume index (SVI) after 7 ml·kg-1 colloid administration) in patients with AIS undergoing PSF during low Vt ventilation. Secondary outcomes were estimation of the diagnostic performance of pulse pressure variation (PPV), stroke volume variation (SVV), and the combination of IJVV and PPV in predicting fluid responsiveness in this surgical setting. The ability of each parameter to predict fluid responsiveness was assessed using a receiver operating characteristic curve.ResultsFifty-six patients were included, 36 (64.29%) of whom were deemed fluid responsive. No significant difference in baseline IJVV was found between responders and non-responders (25.89% vs. 23.66%, p = 0.73), and no correlation was detected between baseline IJVV and the increase in SVI after volume expansion (r = 0.14, p = 0.40). A baseline IJVV greater than 32.00%, SVV greater than 14.30%, PPV greater than 11.00%, and a combination of IJVV and PPV greater than 64.00% had utility in identifying fluid responsiveness, with a sensitivity of 33.33%, 77.78%, 55.56%, and 55.56%, respectively, and a specificity of 80.00%, 50.00%, 65.00%, and 65.00%, respectively. The area under the receiver operating characteristic curve for the baseline values of IJVV, SVV, PPV, and the combination of IJVV and PPV was 0.52 (95% CI, 0.38–0.65, p=0.83), 0.54 (95% CI, 0.40–0.67, p=0.67), 0.58 (95% CI, 0.45–0.71, p=0.31), and 0.57 (95% CI, 0.43–0.71, p=0.37), respectively.ConclusionsUltrasonic-derived IJVV lacked accuracy in predicting fluid responsiveness in patients with AIS undergoing PSF during low Vt ventilation. In addition, the baseline values of PPV, SVV, and the combination of IJVV and PPV did not predict fluid responsiveness in this surgical setting.Trail registrationThis trial was registered at www.chictr.org (ChiCTR2200064947) on 24/10/2022. All data were collected through chart review.

Inferior vena cava ultrasound and other techniques for assessment of intravascular and extravascular volume: an update.

Goals of volume management are to accurately assess intravascular and extravascular volume and predict response to volume administration, vasopressor support or volume removal. Data are reviewed that support the following: (i)Dynamic parameters reliably guide volume administration and may improve clinical outcomes compared with static parameters, but some are invasive or only validated with mechanical ventilation without spontaneous breathing. (ii)Ultrasound visualization of inferior vena cava (IVC) diameter variations with respiration reliably assesses intravascular volume and predicts volume responsiveness. (iii)Although physiology of IVC respiratory variations differs with mechanical ventilation and spontaneous breathing, the IVC collapsibility index (CI) and distensibility index are interconvertible. (iv)Prediction of volume responsiveness by IVC CI is comparable for mechanical ventilation and spontaneous breathing patients. (v)Respiratory variations of subclavian/proximal axillary and internal jugular veins by ultrasound are alternative sites, with comparable reliability. (vi)Data support clinical applicability of IVC CI to predict hypotension with anesthesia, guide ultrafiltration goals, predict dry weight, predict intra-dialytic hypotension and assess acute decompensated heart failure. (vii)IVC ultrasound may complement ultrasound of heart and lungs, and abdominal organs for venous congestion, for assessing and managing volume overload and deresuscitation, renal failure and shock. (viii)IVC ultrasound has limitations including inadequate visualization. Ultrasound data should always be interpreted in clinical context. Additional studies are required to further assess and validate the role of bedside ultrasonography in clinical care.

Correlation of carotid corrected flow time and respirophasic variation in blood flow peak velocity with stroke volume variation in elderly patients under general anaesthesia

BackgroundAccurate assessment of volume responsiveness in elderly patients is important as it may reduce the risk of post-operative complications and enhance surgical recovery. This study evaluated the utility of two Doppler ultrasound-derived parameters, the carotid corrected flow time (FTc) and respirophasic variation in carotid artery blood flow peak velocity (ΔVpeak), to predict volume responsiveness in elderly patients under general anaesthesia.MethodsA total of 97 elderly patients undergoing elective abdominal surgery under general anaesthesia were enrolled in this prospective observational study. After entering the operating room, all patients underwent radial artery puncture connected with a LiDCO device to measure stroke volume variation (SVV), and fluid therapy was performed after anaesthesia induction. Patients were classified as responders if SVV ≥ 13% before fluid challenge and nonresponders if SVV < 13%. The FTc, ΔVpeak, SVV and haemodynamic data were measured by ultrasound at baseline (T0) and before (T1) and after (T2) fluid challenge. The correlations between the Doppler ultrasound-derived parameters and SVV were analysed, and the receiver operating characteristic (ROC) curves was computed to characterize both FTc and ΔVpeak as measures of volume responsiveness in elderly patients.ResultsForty-one (42.3%) patients were fluid responders. Carotid FTc before fluid challenge was negatively correlated with SVV before fluid challenge (r = -0.77; P < 0.01), and ΔVpeak was positively correlated with SVV (r = 0.72; P < 0.01). FTc and ΔVpeak predicted SVV ≥ 13% after general anaesthesia in elderly patients, with areas under the receiver operating characteristic curves (AUROCs) of 0.811 [95% confidence interval (CI), 0.721–0.900; P < 0.001] and 0.781 (95% CI, 0.686–0.875; P < 0.001), respectively. The optimal cut-off values of FTc and ΔVpeak to predict SVV ≥ 13% were 340.74 ms (sensitivity of 76.8%; specificity of 80.5%) and 11.69% (sensitivity of 78.0%; specificity of 67.9%), respectively.ConclusionsThere was a good correlation between carotid artery ultrasound parameters and SVV. FTc predicted fluid responsiveness better than ΔVpeak in elderly patients during general anaesthesia. Further study is needed before these parameters can be recommended for clinical application.Trial registrationwww.chictr.org.cn(ChiCTR2000031193); registered 23 March 2020.

Influencing factors and countermeasures of pulse pressure variation in predicting volume responsiveness in patients with acute respiratory distress syndrome

脉压变异率（PPV）作为心肺交互的产物，是预测容量反应性的动态指标，但PPV预测急性呼吸窘迫综合征患者容量反应性受到诸多因素影响，如小潮气量通气、自主呼吸、腹内高压，此时可通过改变PPV阈值、潮气量挑战、叹息试验等方法提高其预测准确性；当PPV预测容量反应性准确性受到呼吸系统顺应性降低或右心功能不全影响时，则需要通过被动抬腿试验和呼气末阻断试验才能准确预测容量反应性。.

The diagnostic accuracy of inferior vena cava respiratory variation in predicting volume responsiveness in patients under different breathing status following abdominal surgery

BackgroundThe validation of inferior vena cava (IVC) respiratory variation for predicting volume responsiveness is still under debate, especially in spontaneously breathing patients. The present study aims to verify the effectiveness and accuracy of IVC variability for volume assessment in the patients after abdominal surgery under artificially or spontaneously breathing.MethodsA total of fifty-six patients after abdominal surgeries in the anesthesia intensive care unit ward were included. All patients received ultrasonographic examination before and after the fluid challenge of 5 ml/kg crystalloid within 15 min. The same measurements were performed when the patients were extubated. The IVC diameter, blood flow velocity–time integral of the left ventricular outflow tract, and cardiac output (CO) were recorded. Responders were defined as an increment in CO of 15% or more from baseline.ResultsThere were 33 (58.9%) mechanically ventilated patients and 22 (39.3%) spontaneously breathing patients responding to fluid resuscitation, respectively. The area under the curve was 0.80 (95% CI: 0.68–0.90) for the IVC dimeter variation (cIVC1) in mechanically ventilated patients, 0.87 (95% CI: 0.75–0.94) for the collapsibility of IVC (cIVC2), and 0.85 (95% CI: 0.73–0.93) for the minimum IVC diameter (IVCmin) in spontaneously breathing patients. The optimal cutoff value was 15.32% for cIVC1, 30.25% for cIVC2, and 1.14 cm for IVCmin. Furthermore, the gray zone for cIVC2 was 30.72 to 38.32% and included 23.2% of spontaneously breathing patients, while 17.01 to 25.93% for cIVC1 comprising 44.6% of mechanically ventilated patients. Multivariable logistic regression analysis indicated that cIVC was an independent predictor of volume assessment for patients after surgery irrespective of breathing modes.ConclusionIVC respiratory variation is validated in predicting patients' volume responsiveness after abdominal surgery irrespective of the respiratory modes. However, cIVC or IVCmin in spontaneously breathing patients was superior to cIVC in mechanically ventilated patients in terms of clinical utility, with few subjects in the gray zone for the volume responsiveness appraisal.Trial registrationChiCTR-INR-17013093. Initial registration date was 24/10/2017.

End-tidal carbon dioxide partial pressure to assess the value of passive leg-raising test in predicting volume responsiveness in patients with septic shock

To investigate the value of partial pressure of end-tidal carbon dioxide (PETCO2) combined with passive leg raising test (PLR) in predicting volume responsiveness in patients with septic shock. A total of 43 patients with septic shock admitted to the second department of critical care medicine, People's Hospital of Xinjiang Uygur Autonomous Region from December 2019 to June 2021 were selected as the research subjects. PETCO2, cardiac index (CI), stroke volume variation (SVV), mean arterial pressure (MAP) and other hemodynamic indexes were monitored before and after PLR and volume stress test (VE). Subjects were grouped according to the CI variation rate (ΔCI) after VE test. Patients with ΔCI ≥ 15% were the responding group, and patients with ΔCI < 15% were the non-responding group. The receiver operator characteristic curve (ROC curve) was drawn to analyze the evaluation value of the change in PETCO2 after PLR on the evaluation value of fluid responsiveness. Among the 43 patients, 22 cases were in the responding group, accounting for 51.2%; 21 cases were in the non-responding group, accounting for 48.8%. After the PLR test, the change values of MAP, SVV, CI and PETCO2 in the responding group were higher than those in the non-responding group, and the differences were statistically significant [MAP (mmHg): 3.8±2.1 vs. 1.4±2.0, SVV (%): -5.3±2.5 vs. 2.7±2.0, CI (mL×s-1×m-2): 0.48±0.13 vs. 0.14±0.18, PETCO2 (mmHg): 3.4±1.8 vs. 1.1±1.0, all P < 0.05, 1 mmHg ≈ 0.133 kPa]. After the VE test, the changes of HR, MAP, SVV, CI and PETCO2 in the responding group were higher than those in the non-responding group [HR (times/min): -8.3±2.8 vs. -2.3±3.7, MAP (mmHg): 3.8±2.4 vs. 1.2±1.7, SVV (%): -6.3±3.1 vs. -3.3±2.0, CI (mL×s-1×m-2): 0.51±0.14 vs. 0.16±0.12, PETCO2 (mmHg): 3.3±1.2 vs. 1.3±1.1, all P < 0.05]. The area under the ROC curve (AUC) of the change in PETCO2 before and after the PLR test (ΔPETCO2 PLR) for evaluating fluid responsiveness was 0.881. When the critical value was 5.9%, the sensitivity was 76.7%, the specificity was 89.5%, and the correct index was 0.68; the AUC for SVV baseline assessment of fluid responsiveness was 0.835, and when the cut-off value was 12.8%, the sensitivity was 84.6%, the specificity was 80.0%, and the correct index was 0.65. The predictive value of ΔPETCO2 was not lower than the SVV baseline. After the PLR test, the change of PETCO2 can be used as a non-invasive, simple, safe and reliable indicator for predicting the volume responsiveness of patients with septic shock.

Efficacy of Stroke Volume Variation-guided Fluid Management of Patients undergoing Off-pump Coronary Artery Bypass Grafting: An Observational Comparative Study between Open and Closed Chest

Introduction: Functional haemodynamic monitoring using dynamic parameter such as Stroke Volume Variation (SVV), based on pulse contour analysis, helps in predicting fluid responsiveness in off pump Coronary Artery Bypass Grafting (CABG) surgery. This allows adequate volume replacement to achieve optimal cardiac performance. Aim: To evaluate the efficacy of SVV in predicting volume responsiveness and effect on haemodynamic variable in patients undergoing off pump CABG in both closed and open chest. Materials and Methods: This single-centre, non randomised observational study was conducted at a tertiary medical college and hospital (LokmanyaTilak Municipal Medical College and General Hospital) Mumbai, Maharashtra, India, from December 2016 to December 2018. A total of 34 patients undergoing elective off pump CABG were included. Haemodynamic measurements Stroke Volume (SV), Cardiac Output (CO), Cardiac Index (CI), and SVV, were recorded with the transducer positioned at the level of midaxillary line. If the SVV was equal to or higher than 12, 100 mL fluid aliquot was given to patients. Endpoints for fluid aliquots was increase in CO by 15%, decrease in SVV of less than 12 or an increase Central Venous Pressure (CVP) upto 15 millimeter of mercury (mmHg). Number of times SVV above 12 during the procedure was recorded. SVV was considered as fluid responsive “if there was an increase in SV by 5%”. Statistical analysis was done using Student’s t-test (two tailed, dependent) on continuous parameters. The p-value &lt;0.05, was considered significant. Results: Out of 103 events of rise in SVV, 65 (63.1%) occurred when chest was open and 38 (36.9%) while chest was closed. The SVV-guided fluid response was 76.3% in closed chest and 75.4% in open chest and there was no significant difference. (p-value=0.91). There was a significant increase in SV (p-value&lt;0.01), CO (p-value=0.04), and significant decrease in SVV (p-value&lt;0.01) and heart rate (p-value&lt;0.01) after fluid loading in the responsive group when compared with non responsive group. There was no statistically significant difference between percentage change in SV, CO, CI, SBP, DBP, MAP and CVP between closed and open chest conditions after fluid replacement. Conclusion: SVV is not affected by open or closed chest conditions in mechanically ventilated patients undergoing CABG and can be used as a guide for fluid replacement. Weather open or closed chest conditions, few patients do not respond to fluid replacement when SVV are more than 12 by an increase in SV, cardiac output or CI, the cause of which remains to be determined.

PASSIVE LEG RAISING EFFECT AT RESUSCITATION AMONG PATIENTS WITH VASOPLEGIC STATE

Background: Several dynamic parameters have been used clinically to predict volume responsiveness and to guide fluid administration of which passive leg raising (PLR) is one of the most reliable techniques. PLR induces rising in cardiac output attributes through an unstressed volume mobilization from legs to heart causing autologous preload increment. Appropriate fluid resuscitation is essential and can be optimized by hemodynamic-based approach to vasodilatory hypotension.&#x0D; Objective: This study aimed to evaluate the effectiveness and safety of PLR at early resuscitation among patients with vasoplegia.&#x0D; Methods: We conducted a comparison study concerning an experimental design using a single blinded assessment of the outcomes that assigned patients with shock to be treated with PLR or flat position at early resuscitation. Forty patients with shock were included in this study. Twenty patients performed PLR at early resuscitation compared with the others that performed in the flat position and were measured for cardiac output (CO), mean arterial pressure (MAP), diastolic blood pressure (DBP), heart rate (HR), central venous pressure (CVP) and systemic vascular resistance (SVR) immediately after the procedures. The primary outcome was to evaluate the effect of early PLR on hemodynamic variables among hypotensive patients by comparing the difference in CO while the secondary outcomes were differences in MAP, DBP, HR, CVP, SVR, survival at hospital admission and the pulmonary complications of chest x-rays between the two groups.&#x0D; Results: No difference was observed in baseline characteristics between the two groups of patients. Compared with the flat position, PLR at early resuscitation significantly increased CO (3.57 ± 0.27 vs. 2.2 ± 0.18 L/min, p = 0.037), MAP (22.48 ± 5.6 vs. 10.83 ± 4 mmHg, p&lt;0.001), DBP (19 ± 0.20 vs. 1.23 ± 0.12 mmHg, p=0.001) and CVP (4.52 ± 0.19 vs. 2.18 ± 0.13 mmHg, p=0.002). However, no differences were observed in HR, SVR, pulmonary complications of chest X-rays [2 (10%) vs. 1 (5%), p = 0.23] as well as survival at hospital admission [16 (80%) vs. 13 (65%), p = 0.48] between the two groups.&#x0D; Conclusion: Among patients with shock, PLR at early resuscitation significantly increased CO, MAP, DBP and CVP than that of those performing the flat position. No differences were found in HR, SVR, pulmonary complications; PLR did not improve survival to hospital admission.

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.

Assessing volume responsiveness using right ventricular dynamic indicators of preload

PurposeDynamic indicators of preload currently only do reflect preload requirements of the left ventricle. To date, no dynamic indicators of right ventricular preload have been established. The aim of this study was to calculate dynamic indicators of right ventricular preload and assess their ability to predict ventricular volume responsiveness.Materials and methodsThe study was designed as experimental trial in 20 anaesthetized pigs. Micro-tip catheters and ultrasonic flow probes were used as experimental reference to enable measurement of right ventricular stroke volume and pulse pressure. Hypovolemia was induced (withdrawal of blood 20 ml/kg) and thereafter three volume-loading steps were performed. ROC analysis was performed to assess the ability of dynamic right ventricular parameters to predict volume response.ResultsROC analysis revealed an area under the curve (AUC) of 0.82 (CI 95% 0.73–0.89; p < 0.001) for right ventricular stroke volume variation (SVVRV), an AUC of 0.72 (CI 95% 0.53–0.85; p = 0.02) for pulmonary artery pulse pressure variation (PPVPA) and an AUC of 0.66 (CI 95% 0.51–0.79; p = 0.04) for pulmonary artery systolic pressure variation (SPVPA).ConclusionsIn our experimental animal setting, calculating dynamic indicators of right ventricular preload is possible and appears promising in predicting volume responsiveness.

Inferior Vena Cava Collapsibility Index: Clinical Validation and Application for Assessment of Relative Intravascular Volume.

Accurate assessment of relative intravascular volume is critical to guide volume management of patients with acute or chronic kidney disorders, particularly those with complex comorbidities requiring hospitalization or intensive care. Inferior vena cava (IVC) diameter variability with respiration measured by ultrasound provides a dynamic noninvasive point-of-care estimate of relative intravascular volume. We present details of image acquisition, interpretation, and clinical scenarios to which IVC ultrasound can be applied. The variation in IVC diameter over the respiratory or ventilatory cycle is greater in patients who are volume responsive than those who are not volume responsive. When 2 recent prospective studies of spontaneously breathing patients (n=214) are added to a prior meta-analysis of 181 patients, for a total of 7 studies of 395 spontaneously breathing patients, IVC collapsibility index (CI) had a pooled sensitivity of 71% and specificity of 81% for predicting volume responsiveness, which is similar to a pooled sensitivity of 75% and specificity of 82% for 9 studies of 284 mechanically ventilated patients. IVC maximum diameter <2.1 cm, that collapses >50% with or without a sniff is inconsistent with intravascular volume overload and suggests normal right atrial pressure (0-5 mmHg). Inferior vena cava collapsibility (IVC CI)<20% with no sniff suggests increased right atrial pressure and is inconsistent with overt hypovolemia in spontaneously breathing or ventilated patients. These IVC CI cutoffs do not appear to vary greatly depending on whether patients are breathing spontaneously or are mechanically ventilated. Patients with lower IVC CI are more likely to tolerate ultrafiltration with hemodialysis or improve cardiac output with ultrafiltration. Our goal for IVC CI generally ranges from 20% to 50%, respecting potential biases to interpretation and overriding clinical considerations. IVC ultrasound may be limited by factors that affect IVC diameter or collapsibility, clinical interpretation, or optimal visualization, and must be interpreted in the context of the entire clinical situation.

Pulse Pressure Variation is a Valuable Marker for Predicting Fluid Responsiveness in Brain-Dead Donors

PurposeHemodynamic management in brain-dead donors (BDDs) is challenging due to hemodynamic instabilities. We compared functional parameters with traditional parameters for hemodynamic monitoring in BDDs. Materials and methodsSeventeen BDDs with a positive balance of >500 mL for 8 hours were included. Functional hemodynamic monitoring, including pulse pressure variation (PPV), stroke volume variation (SVV), cardiac output, and systemic vascular resistance index (SVRI) was performed in the setting of tidal volume of 6 mL/kg to 8 mL/kg and minimal positive end-expiratory pressure of 5 cm to 8 cm H2O. Responders were defined by a cardiac output increase of >15% after fluid therapy. ResultsAmong the 17 BDDs (mean age, 46.80±13.91 years), 15 were male. Seven responders out of 17 (41.1%) had a significantly higher PPV (22.8±8.4 vs 13.4±5.9%, P = .038) and serum albumin level (3.2±0.6 vs 2.6±0.5 g/L, P = .040) at baseline than nonresponders. However, other hemodynamic markers such as SVV and SVRI were similar between groups. Traditional markers of volume status, such as heart rate, central venous pressure, hemoglobin, and serum uric acid level were also similar between the 2 groups. Hemodynamic markers including PPV, SVV, and SVRI were significantly reduced in responders. ConclusionsPPV was the most valuable hemodynamic marker for predicting volume responsiveness in BDDs.

Comparison of global end-diastolic volume index derived from jugular and femoral indicator injection: a prospective observational study in patients equipped with both a PiCCO-2 and an EV-1000-device

Transpulmonary thermodilution (TPTD)-derived global end-diastolic volume index (GEDVI) is a static marker of preload which better predicted volume responsiveness compared to filling pressures in several studies. GEDVI can be generated with at least two devices: PiCCO and EV-1000. Several studies showed that uncorrected indicator injection into a femoral central venous catheter (CVC) results in a significant overestimation of GEDVI by the PiCCO-device. Therefore, the most recent PiCCO-algorithm corrects for femoral indicator injection. However, there are no systematic data on the impact of femoral indicator injection for the EV-1000 device. Furthermore, the correction algorithm of the PiCCO is poorly validated. Therefore, we prospectively analyzed 14 datasets from 10 patients with TPTD-monitoring undergoing central venous catheter (CVC)- and arterial line exchange. PiCCO was replaced by EV-1000, femoral CVCs were replaced by jugular/subclavian CVCs and vice-versa. For PiCCO, jugular and femoral indicator injection derived GEDVI was comparable when the correct information about femoral catheter site was given (p = 0.251). By contrast, GEDVI derived from femoral indicator injection using the EV-1000 was obviously not corrected and was substantially higher than jugular GEDVI measured by the EV-1000 (846 ± 250 vs. 712 ± 227 ml/m2; p = 0.001). Furthermore, measurements of GEDVI were not comparable between PiCCO and EV-1000 even in case of jugular indicator injection (p = 0.003). This is most probably due to different indexations of the raw value GEDV. EV-1000 could not be recommended to measure GEDVI in case of a femoral CVC. Furthermore, different indexations used by EV-1000 and PiCCO should be considered even in case of a jugular CVC when comparing GEDVI derived from PiCCO and EV-1000.

Assessment of end-tidal carbon dioxide and vena cava collapsibility in volume responsiveness in spontaneously breathing patients.

The benefit of end-tidal carbon dioxide (ETCO2) and inferior vena cava collapsibility index (IVCCI) in predicting fluid responsiveness in mechanically ventilated patients has been demonstrated. However, the data on spontaneously breathing patients is controversial. This study aims to investigate the accuracy of variations in the ETCO2 (∆ETCO2) and IVCCI (∆IVCCI) gradient in predicting volume responsiveness in spontaneously breathing patients with hypovolemia. This was aprospective observational study conducted in an academic emergency department (ED). Spontaneously breathing patients who required fluid resuscitation due to hypovolemia were included in the study. Cardiac output (CO), IVCCI and ETCO2 were measured before and after the passive leg raise (PRL). Achange in the CO of ≥15% after the PLR were considered volume responsive. The difference in the ∆ETCO2 and ∆IVCCI were compared between the volume responsive and nonresponsive groups. Atotal of 31patients were included in the study, of whom 15patients were volume responsive. The difference in the ∆ETCO2 was 4 mm Hg in the volume responsive and 2 mm Hg in the nonresponsive group (p = 0.02). There was no significant difference in ∆IVCCI between the groups. Amoderate correlation was detected between the difference in ∆ETCO2 and CO (0.585; p = 0.001). ∆ETCO2 can be an alternative method in predicting volume responsiveness in spontaneously breathing patients with hypovolemia.

Accuracy assessment of noninvasive cardiac output monitoring in the hemodynamic monitoring in critically ill patients.

The consistency of cardiac output (CO) measured by noninvasive cardiac output monitoring (NICOM), pulse index continuous cardiac output (PiCCO), and ultrasound in the hemodynamic monitoring of critically ill patients was studied. Using the NICOM built-in passive leg raising (PLR) test, stroke volume index variation (∆SVI) was calculated and was used to predict volume responsiveness in patients with circulatory shock (excluding cardiogenic shock). Critically ill patients requiring hemodynamic monitoring were admitted during the study period. The CO of each included patient under hemodynamic monitoring was measured by NICOM plus PiCCO or ultrasound, and the consistency of the measured COs was analyzed. By the NICOM built-in PLR test, ∆SVI was calculated and was used to predict volume responsiveness. The CO of 58 patients was measured by NICOM and ultrasound, and the COs measured by these two methods were consistent. The CO of 40 patients was measured by NICOM and PiCCO, and the COs measured by these two methods were consistent. The volume responsiveness of all 98 patients was assessed by the NICOM built-in PLR test. A total of 60 patients had ∆SVI >10%, so they underwent the fluid challenge. Among them, 43 patients were positive by both the NICOM built-in PLR and fluid challenge. When using ∆SVI to predict volume responsiveness in patients with circulatory shock (excluding cardiogenic shock), the area under the receiver operating characteristic curve was 0.754 (95% confidence interval, 0.626-0.856), and the cut-off value was 18% (sensitivity: 88.37%, specificity: 52.94%), indicating that ∆SVI has value in predicting the volume responsiveness of patients with noncardiogenic circulatory shock. NICOM had good consistency with ultrasound and PiCCO in the hemodynamic monitoring of critically ill patients and can be for hemodynamic monitoring and evaluation in critically ill patients. The ∆SVI obtained by the NICOM built-in PLR test has certain clinical value in predicting the volume responsiveness of patients with circulatory shock (excluding cardiac shock) and provides a method for evaluating the volume responsiveness of critically ill patients.

Respiratory Variations in Aortic Blood Flow to Predict Volume Responsiveness in Ventilated Children With Leukemia and Neutropenic Septic Shock.

To investigate whether respiratory variations in aortic blood flow by echocardiography can accurately predict volume responsiveness in ventilated children with leukemia and neutropenic septic shock. A prospective study. A 25-bed PICU of a tertiary hospital. Mechanically ventilated children with leukemia who had been exposed to anthracyclines and exhibited neutropenic septic shock were enrolled. Transthoracic echocardiography was performed to monitor the aortic blood flow before and after fluid administration. After volume expansion, left ventricular stroke volume increased by greater than or equal to 15% in 16 patients (responders) and less than 15% in 14 patients (nonresponders). The performance of respiratory variation in velocity time integral of aortic blood flow and respiratory variation in peak velocity of aortic blood flow for predicting volume responsiveness, as determined by the area under the receiver operating characteristic curve, was 0.74 (95% CI, 0.55-0.94; p = 0.025) and 0.71 (95% CI, 0.53-0.90; p = 0.048), respectively. Positive end-expiratory pressure was higher in nonresponders than in responders (p = 0.035). Respiratory variation in velocity time integral of aortic blood flow and respiratory variation in peak velocity of aortic blood flow derived from transthoracic echocardiography showed only a fair reliability in predicting volume responsiveness in ventilated children with leukemia and neutropenic septic shock.

Application of variation of internal jugular vein respiration for predicting fluid responsiveness in patients undergoing laparo- scopic surgery

Objective To evaluate the application of variation of internal jugular vein respiration (VIJVR) for predicting fluid responsiveness in patients undergoing laparoscopic surgery. Methods A total of 44 patients, aged 40- 65, with body mass index (BMI) of 18-25 kg/m2, American Society of Anesthesiologists (ASA) Ⅰ or Ⅱ , were selected who received laparoscopic radical resection for rectal cancer from November 2016 to March 2017 in Northern Jiangsu People's Hospital. After patients entered into the room, their electrocardiogram (ECG), heart rate, pulse oxygen saturation (SpO2) and noninvasive blood pressure (NIBP), central vein pressure (CVP), cardiac output (CO), cardiac index (CI), stroke volume variation (SVV), and stroke volume index (SVI) were monitored. The max-imum and minimum diameters of the internal jugular vein (DIJVmax and DIJVmin) were measured by ultrasound within three respiratory cycles and VIJVR was calculated as the following formula: VIJVR=[(DIJVmax-DIJVmin)/DIJVmin] ×100%. Then, 10 min after the beginning of laparoscopy, 6% hydroxyethyl starch 130/0.4 (HES130/0.4, 500 ml) in sodium chloride injection water was infused at a dose of 7 ml/kg within 15 min. Meanwhile, heart rate, blood pressure, CO, CI, SVV, SVI and VIJVR were recorded 10 min after tracheal intubation (T1), 10 min after the beginning of pneumoperitoneum (T2) and 10 min after the end of infusion of 6% HES130/0.4 (T3). According to the increase of stroke volume index (△SVI) after volume challenge, the patients were divided into responders (group R, △SVI≥15%, n=29) and non-responders (group N, △SVI<15%, n=15). The relationship between VIJVR and fluid responsiveness was analyzed by receiver operating characteristic (ROC) curve. Results The VIJVR before volume challenge was negatively related with △SVI in the presence of pneumoperitoneum (r=-0.451, P<0.05). The area under the ROC curve (AUC) of VIJVR to predict volume responsiveness was 0.83 (95%CI 0.705-0.950, P<0.05), with a sensitivity of 65.5% and a specificity of 93.3% when the cut-off value of VIJVR was 21% for predicting volume responsiveness. Conclusions VIJVR can well predict fluid responsiveness in patients undergoing laparoscopic surgery. Key words: Variation of internal jugular vein respiration; Therapeutic laparoscopy; Fluid responsiveness

The role of internal jugular vein and inferior vena cava distensibility indices as parameters of fluid responsiveness in mechanically ventilated septic shock patients

Context The use of dynamic parameters for the assessment of fluid responsiveness in septic shock patients has increased in recent years. Aims In this study, we examined the ability of internal jugular vein distensibility index (ΔDIJV) and inferior vena cava distensibility index (ΔDIVC) to predict volume responsiveness in the management of mechanically ventilated septic shock patients. Settings and design Prospective interventional cohort study. Patients and methods This study enrolled 34 septic shock patients. Hemodynamic data coupled with echocardiographic assessment of cardiac index (ΔCI), ΔDIVC, and ΔDIJV were assessed before and after 7 ml/kg fluid challenge. Patients were considered as fluid responders if a rise in ΔCI more than or equal to 15% took place after volume expansion, and if ΔCI was less than 15%, the patients were considered nonresponders. Results The area under the curve of ΔDIVC was 0.940 with the best cut off value of less than or equal to 13.6% with sensitivity, specificity, positive predictive value, and negative predictive value of 94.74, 80.00, 85.7, and 92.3%, respectively. While the area under the curve for ΔDIJV was 0.900 with the best cutoff value of less than or equal to 11.6% with sensitivity, specificity, positive predictive value, and negative predictive value of 84.21, 80.00, 84.2, and 80.0%, respectively. Conclusions Ultrasonic evaluation of respirophasic changes of internal jugular vein is a simple, easy, and readily accessible bedside measure of fluid responsiveness in mechanically ventilated, sedated septic shock patients. ΔDIJV can predict fluid responsiveness with good sensitivity, specificity, and overall accuracy. Meanwhile, ΔDIVC is still more sensitive with better overall accuracy.

Predictive Ability of PEEP Induced Changes in CVP to Predict Volume Responsiveness in Mechanically Ventilated Patients After Major Abdominal Surgery

Predictive Ability of PEEP Induced Changes in CVP to Predict Volume Responsiveness in Mechanically Ventilated Patients After Major Abdominal Surgery