Stroke Volume Variation Values Research Articles

Comparison of pulse pressure and stroke volume variations measured by three monitors in high-risk surgical patients

IntroductionDynamic indices of fluid responsiveness (FR) such as pulse pressure variation (PPV) and stroke volume variation (SVV) differ among hemodynamic monitors, which use proprietary algorithms, and vary even over a short period of time. We aimed to compare the baseline values, fluctuation and predictive value for FR of PPV and SVV measured by three minimally invasive monitors. Patients and methodsTwenty patients undergoing high-risk abdominal surgery were included and 45 fluid challenges were analysed. The patients were simultaneously monitored using Carescape B650, LiDCO Rapid and FloTrac/Vigileo system. Cardiac output (CO), PPV and SVV were recorded before and after the fluid challenge of 500ml of balanced crystalloid solution. An increase in CO ≥ 15 % defined fluid responders. Concurrently recorded arterial waveform was used for offline calculation of PPV. ResultsMean baseline values of the indices ranged between 8.6% and 13.4%. LiDCO showed higher fluctuation of indices compared to the other monitors. Area under the receiver operating characteristic curve (AUROC) ranged from 0.71 to 0.76 with optimal cut-off value between 7.5% and 13.9%. AUROC increased for all indices when FR was defined as an increase in stroke volume. Furthermore, a decrease in PPV or SVV after fluid challenge (ΔPPV, ΔSVV) proved a better marker of FR (AUROC 0.82 – 0.93) than baseline values with a uniform threshold of approximately -3%. ConclusionsAlthough a significant range of baselines variations and optimal cut-off values was observed, the predictive value of PPV and SVV from all the monitors was only moderate and comparable. Nevertheless, ΔPPV and ΔSVV appear to be a reliable and device-independent markers of FR.

Predicting stroke volume variation using central venous pressure waveform: a deep learning approach

Objective. This study evaluated the predictive performance of a deep learning approach to predict stroke volume variation (SVV) from central venous pressure (CVP) waveforms.Approach. Long short-term memory (LSTM) and the feed-forward neural network were sequenced to predict SVV using CVP waveforms obtained from the VitalDB database, an open-source registry. The input for the LSTM consisted of 10 s CVP waveforms sampled at 2 s intervals throughout the anesthesia duration. Inputs of the feed-forward network were the outputs of LSTM and demographic data such as age, sex, weight, and height. The final output of the feed-forward network was the SVV. The performance of SVV predicted by the deep learning model was compared to SVV estimated derived from arterial pulse waveform analysis using a commercialized model, EV1000.Main results. The model hyperparameters consisted of 12 memory cells in the LSTM layer and 32 nodes in the hidden layer of the feed-forward network. A total of 224 cases comprising 1717 978 CVP waveforms and EV1000/SVV data were used to construct and test the deep learning models. The concordance correlation coefficient between estimated SVV from the deep learning model were 0.993 (95% confidence interval, 0.992-0.993) for SVV measured by EV1000.Significance. Using a deep learning approach, CVP waveforms can accurately approximate SVV values close to those estimated using commercial arterial pulse waveform analysis.

Use of stepwise lung recruitment maneuver to predict fluid responsiveness under lung protective ventilation in the operating room

Recent research has revealed that hemodynamic changes caused by lung recruitment maneuvers (LRM) with continuous positive airway pressure can be used to identify fluid responders. We investigated the usefulness of stepwise LRM with increasing positive end-expiratory pressure and constant driving pressure for predicting fluid responsiveness in patients under lung protective ventilation (LPV). Forty-one patients under LPV were enrolled when PPV values were in a priori considered gray zone (4% to 17%). The FloTrac-Vigileo device measured stroke volume variation (SVV) and stroke volume (SV), while the patient monitor measured pulse pressure variation (PPV) before and at the end of stepwise LRM and before and 5 min after fluid challenge (6 ml/kg). Fluid responsiveness was defined as a ≥ 15% increase in the SV or SV index. Seventeen were fluid responders. The areas under the curve for the augmented values of PPV and SVV, as well as the decrease in SV by stepwise LRM to identify fluid responders, were 0.76 (95% confidence interval, 0.61–0.88), 0.78 (0.62–0.89), and 0.69 (0.53–0.82), respectively. The optimal cut-offs for the augmented values of PPV and SVV were > 18% and > 13%, respectively. Stepwise LRM -generated augmented PPV and SVV predicted fluid responsiveness under LPV.

Evaluating the intraoperative changes in several hemodynamic parameters using uscom method in severe burn patients undergoing burn necrotomy, skin grafting

Objective: To evaluate the intraoperative changes in some hemodynamic parameters by the USCOM method in severe burn patients undergoing burn necrotomy, skin grafting.Subjects and methods: 30 severe burn patients, aged 16-60, treated at the Emergency Department, National Burn Hospital, were scheduled for necrosis and skin grafting from May 2023 to December 2023. Cross-sectional, clinical descriptive study.Results: CO and CI values at all study times were within normal limits (3.5-8 l/min and 2.4-4.2 l/min/m2). CO and CI were highest at the time of pre-medication (6.93 and 4.24) and lowest at the time of skin grafting (5.87 and 3.61). SVR values at all times were within normal limits (800 - 1600 d.s.cm-5). SVR was highest at the time the patient was awake (1278.33) and lowest at the time immediately after induction of anesthesia (976.93). SVRI values at 3 times after induction of anesthesia, before necrotomy, and at the time of necrotomy were lower than normal values (1800-3200 d.s.cm-5.m2). SVI at the remaining time points was within normal limits. SV values at all times were within normal ranges (50-110 cm3). SVI values at most times were smaller than normal values (35 - 65 ml/m2), except for at the time of necrotomy (35.03). SVV values at all times were higher than normal (< 20%).Conclusion: Stroke volume variation (SVV) parameters at all study times were higher than normal values corresponding to the age range. The stroke volume index parameter SVI at most times was lower than the normal value, and SVRI at all times was not higher than the normal value. However, the parameters cardiac output (CO), cardiac index (CI), stroke volume (SV), and systemic vascular resistance (SVR) were all within the range of normal values corresponding to the age range at the research time points.

Validation of Preload Assessment Technologies at Altitude in a Porcine Model of Hemorrhage

IntroductionDynamic preload assessment measures including pulse pressure variation (PPV), stroke volume variation (SVV), pleth variability index (PVI), and hypotension prediction index (HPI) have been utilized clinically to guide fluid management decisions in critically ill patients. These values aid in the balance of correcting hypotension while avoiding over-resuscitation leading to respiratory failure and increased mortality. However, these measures have not been previously validated at altitude or in those with temporary abdominal closure (TAC). MethodsForty-eight female swine (39 ± 2 kg) were separated into eight groups (n = 6) including all combinations of flight versus ground, hemorrhage versus no hemorrhage, and TAC versus no TAC. Flight animals underwent simulated aeromedical evacuation via an altitude chamber at 8000 ft. Hemorrhagic shock was induced via stepwise hemorrhage removing 10% blood volume in 15-min increments to a total blood loss of 40% or a mean arterial pressure of 35 mmHg. Animals were then stepwise transfused with citrated shed blood with 10% volume every 15 min back to full blood volume. PPV, SVV, PVI, and HPI were monitored every 15 min throughout the simulated aeromedical evacuation or ground control. Blood samples were collected and analyzed for serum levels of serum IL-1β, IL-6, IL-8, and TNF-α. ResultsHemorrhage groups demonstrated significant increases in PPV, SVV, PVI, and HPI at each step compared to nonhemorrhage groups. Flight increased PPV (P = 0.004) and SVV (P = 0.003) in hemorrhaged animals. TAC at ground level increased PPV (P < 0.0001), SVV (P = 0.0003), and PVI (P < 0.0001). When TAC was present during flight, PPV (P = 0.004), SVV (P = 0.003), and PVI (P < 0.0001) values were decreased suggesting a dependent effect between altitude and TAC. There were no significant differences in serum IL-1β, IL-6, IL-8, or TNF-α concentration between injury groups. ConclusionsBased on our study, PPV and SVV are increased during flight and in the presence of TAC. Pleth variability index is slightly increased with TAC at ground level. Hypotension prediction index demonstrated no significant changes regardless of altitude or TAC status, however this measure was less reliable once the resuscitation phase was initiated. Pleth variability index may be the most useful predictor of preload during aeromedical evacuation as it is a noninvasive modality.

Performance of four cardiac output monitoring techniques vs. intermittent pulmonary artery thermodilution during a modified passive leg raise maneuver in isoflurane-anesthetized dogs.

This study investigated the performance among four cardiac output (CO) monitoring techniques in comparison with the reference method intermittent pulmonary artery thermodilution (iPATD) and their ability to diagnose fluid responsiveness (FR) during a modified passive leg raise (PLRM) maneuver in isoflurane-anesthetized dogs undergoing acute blood volume manipulations. The study also examined the simultaneous effect of performing the PLRM on dynamic variables such as stroke distance variation (SDV), peak velocity variation (PVV), and stroke volume variation (SVV). Prospective, nonrandomized, crossover design. Six healthy male Beagle dogs. The dogs were anesthetized with propofol and isoflurane and mechanically ventilated under neuromuscular blockade. After instrumentation, they underwent a series of sequential, nonrandomized steps: Step 1: baseline data collection; Step 2: removal of 33 mL kg-1 of circulating blood volume; Step 3: blood re-transfusion; and Step 4: infusion of 20 mL kg-1 colloid solution. Following a 10-min stabilization period after each step, CO measurements were recorded using esophageal Doppler (EDCO), transesophageal echocardiography (TEECO), arterial pressure waveform analysis (APWACO), and electrical cardiometry (ECCO). Additionally, SDV, PVV, and SVV were recorded. Intermittent pulmonary artery thermodilution (iPATDCO) measurements were also recorded before, during, and after the PLRM maneuver. A successful FR diagnosis made using a specific test indicated that CO increased by more than 15% during the PLRM maneuver. Statistical analysis was performed using one-way analysis of variance for repeated measures with post hoc Tukey test, linear regression, Lin's concordance correlation coefficient (ρc), and Bland-Altman analysis. Statistical significance was set at p < 0.05. All techniques detected a reduction in CO (p < 0.001) during hemorrhage and an increase in CO after blood re-transfusion and colloid infusion (p < 0.001) compared with baseline. During hemorrhage, CO increases with the PLRM maneuver were as follows: 33% for iPATD (p < 0.001), 19% for EC (p = 0.03), 7% for APWA (p = 0.97), 39% for TEE (p < 0.001), and 17% for ED (p = 0.02). Concurrently, decreases in SVV, SDV, and PVV values (p < 0.001) were also observed. The percentage error for TEE, ED, and EC was less than 30% but exceeded 55% for APWA. While TEECO and ECCO slightly underestimated iPATDCO values, EDCO and APWACO significantly overestimated iPATDCO values. TEE and EC exhibited good and acceptable agreement with iPATD. However, CO measurements using all four techniques and iPATD did not differ before, during, and after PLRM at baseline, blood re-transfusion, and colloid infusion. iPATD, EC, TEE, and ED effectively assessed FR in hypovolemic dogs during the PLRM maneuver, while the performance of APWA was unacceptable and not recommended. SVV, SDV, and PVV could be used to monitor CO changes during PLRM and acute blood volume manipulations, suggesting their potential clinical utility.

Accuracy of stroke volume variation and pulse pressure variation in predicting fluid responsiveness undergoing one-lung ventilation during thoracic surgery: a systematic review and meta-analysis.

Stroke volume variation (SVV) and pulse pressure variation (PPV) are based on the interaction between the heart and lungs during mechanical ventilation. However, debate continues as to whether SVV and PPV can accurately predict fluid responsiveness during the one-lung ventilation (OLV). We therefore undertook a systematic review and meta-analysis of clinical trials that investigated the diagnostic value of SVV and PPV in predicting fluid responsiveness undergoing OLV during thoracic surgery. The MEDLINE, EMBASE, WANFANG, and CENTRAL databases were systematically searched for studies on the use of SVV and/or PPV in patients undergoing OLV from 2010 to 2021. Heterogeneity was assessed using I2 statistics. The funnel diagram analysis was used to test publication bias. A fixed-effects model was used to calculate the pooled values of sensitivity, specificity, the diagnostic odds ratio (DOR), and the relevant 95% confidence intervals (95% CIs). The summary receiver operating characteristic (SROC) curves were estimated, and the areas under the SROC curve were calculated. In total nine studies, comprising 452 patients were ultimately included in this meta-analysis, including 217 (48%) responders and 235 (52%) nonresponders. After combining the correlation coefficients, a slight heterogeneity was found between SVV and PPV in these selected studies (I2 SVV =19.7%, I2 PPV =15.3%), and the funnel diagram also showed that the P values of SVV and PPV were 0.33 and 0.26. After the pooled analysis, the respective sensitivity of SVV and PPV in predicting fluid responsiveness was 0.66 and 0.61, the specificity was 0.62 and 0.53, the positive likelihood ratios were 1.7 and 1.3, the negative likelihood ratios were 0.55 and 0.74, and the DORs were 3 and 2. The areas under the SROC curve of SVV and PPV were 0.68 and 0.60, respectively, according to STATA SE16 software, and the combined areas under the receiver operating characteristic (ROC) curve of SVV and PPV were 0.681 and 0.604, respectively, according to MedCalc19.0.4 software. Current evidence suggests that SVV and PPV are not suitable for guiding intraoperative fluid therapy due to their poor ability to predict fluid responsiveness in patients undergoing OLV, and we need a better indicator instead.

Sequential treatment of severe pneumonia with respiratory failure and its influence on respiratory mechanical parameters and hemodynamics.

BACKGROUNDThe pathophysiological characteristics of severe pneumonia complicated by respiratory failure comprise pulmonary parenchymal changes leading to ventilation imbalance, alveolar capillary injury, pulmonary edema, refractory hypoxemia, and reduced lung compliance. Prolonged hypoxia can cause acid-base balance disorder, peripheral circulatory failure, blood-pressure reduction, arrhythmia, and other adverse consequences.AIMTo investigate sequential mechanical ventilation’s effect on severe pneumonia complicated by respiratory failure. METHODSWe selected 108 patients with severe pneumonia complicated by respiratory failure who underwent mechanical ventilation between January 2018 and September 2020 at the Luhe Hospital’s Intensive Care Unit and divided them into sequential and regular groups according to a randomized trial, with each group comprising 54 patients. The sequential group received invasive and non-invasive sequential mechanical ventilation, whereas the regular group received invasive mechanical ventilation. Blood-gas parameters, hemodynamic parameters, respiratory mechanical parameters, inflammatory factors, and treatment outcomes were compared between the two groups before and after mechanical-ventilation treatment. RESULTSThe arterial oxygen partial pressure and stroke volume variation values of the sequential group at 24, 48, and 72 h of treatment were higher than those of the conventional group (P < 0.05). The carbon dioxide partial pressure value of the sequential group at 72 h of treatment and the Raw value of the treatment group at 24 and 48 h were lower than those of the conventional group (P < 0.05). The pH value of the sequential group at 24 and 72 h of treatment, the central venous pressure value of the treatment at 24 h, and the Cst value of the treatment at 24 and 48 h were higher than those of the conventional group (P < 0.05). The tidal volume in the sequential group at 24 h of treatment was higher than that in the conventional group (P < 0.05), the measured values of interleukin-6 and tumor necrosis factor-α in the sequential group at 72 h of treatment were lower than those in the conventional group (P < 0.05), and the total time of mechanical ventilation in the sequential group was shorter than that in the conventional group, with a statistically significant difference (P < 0.05).CONCLUSIONTreating severe pneumonia complicated by respiratory failure with sequential mechanical ventilation is more effective in improving respiratory system compliance, reducing inflammatory response, maintaining hemodynamic stability, and improving patient blood-gas levels; however, from this study’s perspective, it cannot reduce patient mortality.

Invasive and Non-invasive Dynamic Parameters to Predict Fluid Responsiveness After Off-pump Coronary Surgery.

ObjectiveThis study aimed to assess the predictive value of invasive and non-invasive dynamic parameters for evaluation of fluid responsiveness after off-pump coronary artery bypass grafting.MethodsThirty-two adult patients after off-pump coronary surgery were enrolled into a single-center pilot prospective observational study. After arrival to the intensive care unit, all patients received standard fluid challenge test to assess fluid responsiveness. The patients with an increase in cardiac index ≥ 15% after the test were defined as fluid responders. We measured pulse pressure variation using 2 monitoring systems (PPVPiCCO and PPVNK), stroke volume variation, heart–lung interaction index, and plethysmogram variability index before and after standard fluid challenge test.ResultsAfter intensive care unit admission, the absolute values of stroke volume variation, PPVPiCCO, PPVNK, and heart–lung interaction index were significantly higher among fluid responders (P < .05). Response to standard fluid challenge test was predicted by dynamic assessment of PPVPiCCO (area under the curve 0.84), PPVNK (area under the curve 0.71), stroke volume variation (area under the curve 0.77), and heart–lung interaction index (area under the curve 0.77) (P < .05). The plethysmogram variability index value did not demonstrate any predictive ability regarding fluid responsiveness (area under the curve 0.5, P = .1).ConclusionsIn patients after off-pump coronary surgery, both invasive parameters such as pulse pressure and stroke volume variations and non-invasive parameter such as heart–lung interaction index are able to predict fluid responsiveness. Thus, these dynamic parameters can be used to guide fluid therapy during the early postoperative period after off-pump coronary surgery.

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.

Dynamic variables predict fluid responsiveness in pre-school and school children undergoing neurosurgery: a prospective observational study.

BackgroundThe evidence that plethysmographic variability index (PVI), pulse pressure variation (PPV), FloTrac/Vigileo-derived stroke volume variation (SVV), and Eadyn (dynamic arterial elastance) predict fluid responsiveness in children is limited by conflicting results. We aim to evaluate their accuracy and reliability to predict fluid responsiveness after induction in children aged 4–9 years undergoing major neurosurgery.MethodsChildren aged 4–9 years undergoing intracranial epileptic foci excision were enrolled. After the induction of anesthesia, fluid loading with 10 mL/kg of Ringer’s solution over 10 min was administered before surgical incision. PVI, PPV, SVV, and Eadyn were measured before and within 5 min after fluid loading. Respiratory variation in aortic blood flow peak velocity (∆Vpeak) >15% at baseline, measured using transthoracic echocardiography, identified fluid “responders”. The abilities of dynamic variables to predict an increase in mean arterial pressure (MAP) of >10% following fluid loading were also assessed.ResultsFourteen (31.8%) of forty-four patients were responders defined by a baseline ∆Vpeak >15%. Before fluid loading, only the PVI value was significantly different between R and NR (P=0.017). Baseline PVI showed fair diagnostic accuracy for fluid responsiveness, with an area under the curve (AUROC) of 0.735 and the cutoff value of 13%. The R group showed a significantly greater absolute change in PPV and SVV after fluid loading from baseline compared with the NR group (P=0.021 and 0.040, respectively). The absolute change in the PPV and SVV values from baseline was greater in R than those in NR (P=0.021 and 0.040, respectively). Twenty (45.5%) showed a MAP increase of >10% following fluid loading and were defined as responders. Baseline ∆Vpeak and SVV showed fair predictive values for a MAP increase of >10% (AUROC =0.758 and 0.715, respectively).ConclusionsPVI at baseline showed fair reliability to predict fluid responsiveness after anesthesia induction in mechanically ventilated children aged 4–9 years undergoing neurosurgery. Baseline ∆Vpeak and SVV were fairly predictive for an increase in MAP following fluid loading.

Effect of different levels of stroke volume variation on the endothelial glycocalyx of patients undergoing colorectal surgery: A randomized clinical trial.

What is the central question of this study? Massive infusion can destroy the endothelial glycocalyx. We compared the serum concentrations of endothelial glycocalyx components and atrial natriuretic peptide and the outcomes of patients with different levels of stroke volume variation (SVV). What is the main finding and its importance? With a decrease in SVV, the serum concentrations of endothelial glycocalyx components and atrial natriuretic peptide increased, whereas the oxygenation index decreased. When the intraoperative SVV was maintained at 7-10%, the patients had better postoperative recovery and shorter postoperative hospital stays. Therefore, it is advisable to maintain the SVV between 7 and 10%. Dynamic haemodynamic parameters, such as stroke volume variation (SVV), can be used for blood volume monitoring. However, studies have determined the SVV threshold but not the optimal level. The endothelial glycocalyx (EG) plays an important role in maintaining vascular permeability. Moreover, rapid and massive infusion can lead to the degradation, shedding and destruction of the EG. We aimed to explore the effects of different SVV values (11-14, 7-10 or 3-6%) on the EG in 54 patients who were scheduled for elective colorectal tumour surgery and to identify the optimal peri-operative fluid therapy strategy. The concentrations of EG degradation products (heparin sulphate, hyaluronic acid and syndecan-1) and atrial natriuretic peptide were higher when the SVV was maintained between 3 and 6% after fluid therapy compared with pre-infusion (P<0.05). Comparison of postoperative complications and hospitalization time among the three SVV levels was not statistically significant (P>0.05). The postoperative hospitalization time in patients with SVV of 7-10% was shorter than that in patients with SVV of 3-6%. Infusion of a large volume of fluid, with increasing EG degeneration and atrial natriuretic peptide concentrations, might be related to postoperative outcomes.

Diagnostic accuracy of stroke volume variation for predicting fluid responsiveness in children undergoing cardiac surgery: A systematic review and meta-analysis.

Stroke volume variation appears to be reliable for predicting fluid responsiveness in adults, and its predictive value in pediatric patients has been recently reported. However, its predictive value in children undergoing cardiac surgery is unclear. A review and meta-analysis were performed on the diagnostic utility of stroke volume variation for predicting fluid responsiveness in children undergoing cardiac surgery. All relevant articles for prospective research assessing the value of stroke volume variation were searched in the Embase, MEDLINE (PubMed), and Cochrane databases through March 2020. The primary outcome was the accuracy of stroke volume variation for predicting fluid responsiveness in children. The combined data were analyzed by a meta-analysis. Publication quality was assessed using the QUADAS (quality assessment for studies of diagnostic accuracy, maximum score) standard guidelines. Six articles were included in the meta-analysis, following the search strategy. A total of 251 children were included from 6 prospective studies. Fluid therapy for all patients used crystalloids or colloids. The results of the analysis revealed a pooled diagnostic odds ratio of 8.23 (95% CI: 3.07-22.11), pooled sensitivity of 0.73 (95% CI: 0.64-0.80), and pooled specificity of 0.66 (95% CI: 0.58-0.74). Additionally, the overall area of the summary receiver operating characteristic curve was 0.78. There was significant moderate heterogeneity in these studies (p<.05, I2 =42.1%) due to thresholds. There was some heterogeneity due to thresholds in the included studies. An evaluation of stroke volume variation may represent a reliable predictor of fluid responsiveness in children undergoing cardiac surgery. After operative cardiac output optimization, the possible impact of goal-directed fluid treatment depending on stroke volume variation on the perioperative outcome in the children population should subsequently be assessed.

Prediction of Fluid Responsiveness by Stroke Volume Variation in Children Undergoing Fontan Operation.

Background Fontan operation is a palliative medical procedure performed on children with single-ventricle defects. As postoperative success of the procedure largely depends on the preload volume, it is necessary to maintain an appropriate pressure gradient between the systemic vein and the left atrium to ensure the effective volume of systemic circulation. However, there is a lack of effective indexes to evaluate fluid responsiveness in Fontan patients. Stroke volume variation (SVV) is a dynamic hemodynamic parameter based on cardiopulmonary interaction in mechanical ventilation. This study is aimed at validating the sensitivity and specificity of SVV and central venous pressure (CVP) in assessing the fluid responsiveness of Fontan patients. Method Sixty-four children with single ventricle who underwent modified Fontan operation between May 2018 and January 2020 were included in this study. Patients were administered 10 ml·kg−1 albumin for fluid challenge within 10 min after cardiopulmonary bypass. Before and after fluid challenge, the invasive arterial pressure module was connected to MostCare™ equipment to collect the cardiac index (CI) and SVV dynamically in a time window of 30 s at a frequency of 1000 Hz. According to the range of CI change, patients with ΔCI ≥ 15% were classified into the responder (R) group and those with ΔCI < 15% into the nonresponder (NR) group. Using SVV and CVP as indicators, the receiver operating characteristic (ROC) curve of the patients was established, and the area under curve (AUC), diagnostic threshold, sensitivity, and specificity were calculated. Results The SVV values were 16.28% (25th and 75th percentiles 14.17%-19.24%) and 13.68% (25th and 75th percentiles 12.90%-15.89%) before and after fluid challenge treatment in responders, respectively, and the values were 18.60 ± 1.83 mmHg before and 20.20 ± 2.39 mmHg for CVP after treatment. The AUC of SVV was 0.74 (95% confidence interval (CI) 0.54-0.94, P < 0.05), and the cutoff value was 16%, offering a sensitivity of 50% and a specificity of 91.7%. Meanwhile, the AUC of CVP was 0.70 (95% CI 0.50-0.92, P > 0.05), and the cutoff value was 19.5 mmHg, offering a sensitivity of 58% and a specificity of 76%. Conclusion SVV exhibited a good predictive value for fluid responsiveness in pediatric Fontan patients. Appropriate fluid therapy according to SVV could improve the cardiac function of such patients. Trial registration. This study was registered in Chinese Clinical Trail Registry on Jan 26, 2018. Registration number is ChiCTR1800014654. Registry URL is http://www.chictr.org.cn/showproj.aspx?proj=25019. This observational prospective study was approved by the Local Ethics Committee of Shanghai Children's Medical Center affiliated to Shanghai Jiao Tong University (SCMCIRB-K2017035).

The value of hypotensive prediction index and dP/dtmax to predict and treat hypotension in a patient with a dilated cardiomyopathy

The Hypotension Prediction Index (HPi) is a new parameter, recently developed to predict the risk of a patient developing a hypotensive event, defined as a fall in mean arterial pressure below 65 mmHg. The calculated HPi value is displayed on a monitor as a number ranging from 1 to 100; where the first warning for the appearance of such event occurs when HPi values exceed 85. A secondary screen shows the stroke volume variation value; the dP/dt max; and the dynamic arterial elastance. We described a patient with a mild to moderately dilated cardiomyopathy that presented several episodes of hypotension after induction of anaesthesia and how by using HPi technology, these were successfully solved. We recommend the use of a HPi value >85 as a warning of intervention, and to use the secondary screen to determine the cause and the treatment. We consider that HPi technology may be a valid alternative for the anaesthetic management of patients with a dilated cardiomyopathy. El Índice de Predicción de la Hipotensión (iPH) es un nuevo parámetro diseñado para predecir el riesgo de aparición de un evento hipotensor, definido como una caída de la presión arterial media por debajo de 65 mmHg. El valor numérico del iPH se muestra en un monitor como un digito que va de 1 a 100, donde la primera alarma de aparición de la hipotensión ocurre cuando dicho valor excede de 85. Una pantalla secundaria muestra el volumen de variación sistólica; el dP/dtmax ; y la elastancia dinámica arterial. Describimos un caso de un paciente con una miocardiopatía dilatada moderada que presento varios episodios de hipotensión tras la inducción anestésica, y cómo usando la tecnología iPH éstos fueron resueltos. Recomendamos usar el valor de iPH > 85 como alarma de intervención, y utilizar la pantalla secundaria para determinar su causa y adecuar su tratamiento. Creemos que la tecnología iHP puede ser una alternativa válida en el manejo anestésico de los pacientes con una miocardiopatía dilatada.

Noninvasive assessment of fluid responsiveness for emergency abdominal surgery in dogs with pulmonary hypertension: Insights into high-risk companion animal anesthesia.

ObjectiveOptimizing cardiac stroke volume during high-risk surgical anesthesia is of particular interest with regard to a therapeutic target to reduce the incidence of postoperative complications. However, intensive fluid management in critically ill small animals with pulmonary hypertension (PH) has been empirically performed, and thus it can be challenging. Stroke volume variation (SVV) has been used as a dynamic preload predictor of fluid responsiveness. We hypothesized that if SVV exhibited robust reliability in the setting of hemodynamically unstable condition, it would provide more precise information on fluid resuscitation to translate it into veterinary anesthesia. Thus the aim of this study was to investigate the utility of SVV measured by the electrical velocimetry (EV) method for predicting fluid responsiveness in dogs with PH.MethodsSixteen dogs undergoing emergency abdominal surgery and diagnosed with PH secondary to myxomatous mitral valve disease (MMVD) on preoperative transthoracic echocardiogram were included. Dogs were randomly assigned to 2 groups with and without inotropic cardiac support with dobutamine. Hemodynamic measurements including stroke volume and SVV derived from the EV device were performed under general anesthesia before (baseline) and after surgery (fluid challenge with a colloid solution defined by a SV increase of ≥ 10%).ResultsIn both groups, SVV elevated significantly after abdominal surgery compared with baseline. In dobutamine infused group, the SVV values decreased significantly after fluid challenge (P < 0.05) with a greater number of responders than saline infused control group (P < 0.01). Receiver operating curve analysis of SVV confirmed high positive predictive value for dogs during dobutamine infusion (P < 0.05; cut-off value of 15%; specificity 90%, sensitivity 82%).ConclusionsNoninvasive EV monitoring may be useful for the prediction of fluid responsiveness in critically ill dogs with left-sided heart failure-related PH. This normalization of dynamic preload indices, which could be achieved more precisely under inotropic support, may prevent further detrimental consequence of fluid loading.

Validation study of the dynamic parameters of pulse wave in pulmonary resection surgery

Abstract Introduction In lung resection surgery, restrictive fluid therapy is recommended due to the risk of acute lung injury. In contrast, this recommendation increases the risk of hypoperfusion. Guided fluid therapy allows individualization of fluid intake. The use of dynamic volume response parameters is not validated during one-lung ventilation. The main objective is the validation of dynamic parameters, stroke volume variation (SVV) and pulse pressure variation (PPV), during lung resection surgery as fluid response predictors, after the administration of 250 ml crystalloid volume loads, if IC Material and methods Pilot, prospective, observational and single centre study. Twenty-five patients monitored with the PiCCO system were included during open lung resection surgery with the patient in a lateral position, one lung ventilation with tidal volume (TV): 6 ml/kg and open chest. Hemodynamic variables were collected before and after volume loading. The results were classified into two groups: volume responders (increase IC ≥ 10% and/or VSI ≥ 10% after volume loading) and non-responders (no increase or increase IC Results In the analysis of ROC curves, SVV and PPV did not reach a discriminative value (AUC SVV: 0.47; AUC PPV: 0.50), despite the decrease in the threshold value of SVV and PPV to initiate an overload of volume during one-lung ventilation, in lateral position and open chest. Conclusions The results obtained show that the values of the dynamic parameters of volume response (SVV ≥ 8% and PPV ≥ 10%) do not discriminate against responders patients and nonresponders during open lung resection surgery.

Estudio de validación de los parámetros dinámicos de onda de pulso en cirugía de resección pulmonar

IntroductionIn lung resection surgery, restrictive fluid therapy is recommended due to the risk of acute lung injury. In contrast, this recommendation increases the risk of hypoperfusion. Guided fluid therapy allows individualization of fluid intake. The use of dynamic volume response parameters is not validated during one-lung ventilation. The main objective is the validation of dynamic parameters, stroke volume variation (SVV) and pulse pressure variation (PPV), during lung resection surgery as fluid response predictors, after the administration of 250ml crystalloid volume loads, if IC<2.5ml/min/m2 and if SVV≥8% and/or PPV≥10%. Material and methodsPilot, prospective, observational and single centre study. Twenty-five patients monitored with the PiCCO system were included during open lung resection surgery with the patient in a lateral position, one lung ventilation with tidal volume (TV): 6ml/kg and open chest. Hemodynamic variables were collected before and after volume loading. The results were classified into two groups: volume responders (increase IC≥10% and/or VSI≥10% after volume loading) and non-responders (no increase or increase IC<10% and/or VSI<10% after volume loading). We assess the diagnostic efficacy of SVV and PPV by analyzing the AUC (area under curve) in the ROC curves. ResultsIn the analysis of ROC curves, SVV and PPV did not reach a discriminative value (AUCSVV: 0.47; AUCPPV: 0.50), despite the decrease in the threshold value of SVV and PPV to initiate an overload of volume during one-lung ventilation, in lateral position and open chest. ConclusionsThe results obtained show that the values of the dynamic parameters of volume response (SVV≥8% and PPV≥10%) do not discriminate against responders patients and non-responders during open lung resection surgery.

Changes in plasma volume before and after major abdominal surgery following stroke volume variation-guided fluid therapy: a randomized controlled trial.

The aim of intraoperative fluid therapy is to avoid both hypovolemia and hypervolemia; however, the patient's exact volume status is difficult to determine during surgery. Fluid optimization guided by stroke volume variation (SVV) has been widely used in patients undergoing major open abdominal surgery. The aim of this study was to evaluate the changes in plasma volume before and after surgery following SVV-guided fluid therapy. Patients were randomly allocated into one of two groups according to the SVV criteria for fluid administration during surgery. In the fixed SVV fluid strategy group, fluid was administered to maintain the SVV below 13%. In the individual SVV group, individual SVV values of each patient were maintained until the end of surgery. Plasma volume, body weight, and extracellular water (ECW) were measured before and after surgery. Plasma volume was estimated using the indocyanine green dilution technique. A total of 118 patients were included. Median (25-75%) plasma volumes in the preoperative and postoperative period were 2.46 (2.20-2.88) L and 2.69 (2.33-3.12) L for the fixed SVV group (N.=57, P=0.133), respectively, and 2.56 (2.23-2.90) L and 2.89 (2.48-3.19) L for the individual SVV group (N.=61, P<0.001), respectively. Fluid administration during surgery to maintain SVV below 13% was effective for maintaining the preoperative plasma volume until the end of surgery in patients undergoing major open stomach or colorectal surgery. This result supports the validity of SVV-guided fluid therapy, which maintains the SVV value below 13%, in terms of maintaining patient volume status.

Application of stroke volume variation-guided liquid therapy in laparoscopic precision hepatectomy

To observe the safety and impact on the short-term prognosis for patients of stroke volume variation (SVV) goal-directed fluid therapy (GDFT) in laparoscopic precision hepatectomy. Methods: A total of 120 patients (18-65 years old) undergoing laparoscopic precision hepatectomy were randomly divided into the fluid therapy group (group S) guided by SVV and the fluid therapy group (group C) guided by central venous pressure group (CVP), with 60 cases in each group. Mean arterial pressure (MAP) and heart rate (HR) were recorded at the following time: at home calm (T0), the operation started (T1), began to cut the liver (T2), the hepatectomy was acheived (T3), and in the end (T4). The lactic acid was measured at T0 to T4 and 1 day after surgery (T5). The amount of blood loss, urine output and fluid supplement, the incidence of intraoperative hypotension, and the use of neophryn were recorded. The recovery of liver function, Hb, and so on were also recorded. Results: Compared with the group C, the number of hypotension cases, the amount of blood loss and the amount of neophryn in the group S were decreased during the operation (P<0.05), while the lactic acid values in the group S were not significantly increased than those in the group C at T3 and T4 (P<0.05) and the elevation of AST, ALT, DBIL and TBIL in the group S was significantly decreased than those in the group C at 1 and 2 d after the operation (P<0.05). Hb and Hct in the group S were higher than those in the group C at 1 d after the surgery (P<0.05). Compared with the group C, the postoperative exhaust time and hospitalization time were shortened in the group S (P<0.05), and the infection rate and ICU admission rate were decreased in the group S (P<0.05). Conclusion: SVV-guided GDFT in laparoscopic precise hepatectomy is safe and effective. It reduces intraoperative blood loss and benefits the short-term prognosis of patients after operations. High SVV value (13%-17%) is adopted at the liver resection stage, and SVV value with 8%-12% at the end of trans-section may be used as one of intraoperative liquid therapy in laparoscopic precise hepatectomy.