Stroke Volume Variation Research Articles

Cardiovascular Parameters Associated With Troponin I as Indicators for 14-Day Mortality in Patients With Septic Shock

BackgroundTroponin I is better than other troponin isoforms for monitoring cardiocyte damage, and correlates with sepsis-related mortality. However, hemodynamic factors possibly interact with cardiac function to affect mortality in sepsis. Thus, this study used parameters from pulse-induced contour cardiac output (PiCCO) to investigate the possibility. MethodsPatients with troponin I tests and sequential organ failure assessment score ≥2 were selected and divided into survivors and nonsurvivors groups and blood troponin I levels between them were compared. Additionally, 65 patients with septic shock and PiCCO records were selected and divided into high cardiac function index (CFI) and low CFI groups and their cardiac function associated with troponin I levels was checked. Furthermore, the patients were classified into 4 subgroups based on CFI and another hemodynamical parameter of PiCCO for identifying if any interaction between CFI and the parameter existed. ResultsHigh blood troponin I levels correlated with high mortality, and with low cardiac function (CFI < 4.5) alone or with low CFI combined with high stroke volume variation (SVV), but did not correlate with global end-diastolic index (GEDI), or systemic vascular resistance index. However, only the subgroup with low CFI and high SVV (CFI < 4.5 and SVV > 10) increased mortality. ConclusionsOur data give an insight into interactions between cardiac and hemodynamic factors to cause cardiocyte damage and suggest that multiple factors (i.e., low CFI and high SVV) should be considered together to evaluate cardiocyte damage and mortality in sepsis.

Effect of pneumoperitoneum and steep reverse-Trendelenburg position on mean systemic filling pressure, venous return, and microcirculation during esophagectomy.

Keeping adequate tissue perfusion during high-risk abdominal surgery is of utmost importance to decrease postoperative complications. The objective was to investigate the alteration in mean systemic filling pressure (MSFP), venous return (VR) and sublingual microcirculation during pneumoperitoneum and steep reverse-Trendelenburg position during thoracolaparoscopic esophagectomy. This is a single-center prospective observational study in operating room at a university hospital. Eleven consecutive patients undergoing minimally invasive esophagectomy. Intraoperative hemodynamic and sublingual microcirculatory variables were simultaneously measured within 5 minutes at the following time points: T1, baseline supine position before the start of surgery; T2, pneumoperitoneum in supine position; T3, steep reverse-Trendelenburg position after the pneumoperitoneum. The cardiac output (CO) was obtained with continuous pulse contour waveform-derived measurements, and the MSFP was estimated with the analogue method. The pneumoperitoneum and reverse-Trendelenburg caused an increase in stroke volume variation (SVV), MSFP and central venous pressure (CVP), and a decrease in the microcirculatory perfusion index (MFI, <0.05). However, changes in CO, pressure gradient of VR, resistance of VR and blood pressure were not consistent and did not differ significantly across timepoints. Moreover, MFI is significantly related to CVP and MSFP but not to CO and blood pressure (BP). Measurements with MFI ≤2 have a higher CVP and MSFP compared to those with MFI >2. Using a CVP ≥23 mmHg to detect MFI ≤2 results in a sensitivity of 61.54% and a specificity of 100%. A high CVP is related to poor microcirculatory flow perfusion even if the macrocirculation has been maintained during pneumoperitoneum.

Prediction of fluid responsiveness in mechanically ventilated cardiac surgical patients: the performance of seven different functional hemodynamic parameters

BackgroundFunctional hemodynamic parameters such as stroke volume and pulse pressure variation (SVV and PPV) have been shown to be reliable predictors of fluid responsiveness in mechanically ventilated patients. Today, different minimally- and non-invasive hemodynamic monitoring systems measure functional hemodynamic parameters. Although some of these parameters are described by the same name, they differ in their measurement technique and thus may provide different results. We aimed to test the performance of seven functional hemodynamic parameters simultaneously in the same clinical setting.MethodsHemodynamic measurements were done in 30 cardiac surgery patients that were mechanically ventilated. Before and after a standardized intravenous fluid bolus, hemodynamics were measured by the following monitoring systems: PiCCOplus (SVVPiCCO, PPVPiCCO), LiDCOrapid (SVVLiDCO, PPVLiDCO), FloTrac (SVVFloTrac), Philips Intellivue (PPVPhilips) and Masimo pulse oximeter (pleth variability index, PVI). Prediction of fluid responsiveness was tested by calculation of receiver operating characteristic (ROC) curves including a gray zone approach and compared using Fisher’s Z-Test.ResultsFluid administration resulted in an increase in cardiac output, while all functional hemodynamic parameters decreased. A wide range of areas under the ROC-curve (AUC’s) was observed: AUC-SVVPiCCO = 0.91, AUC-PPVPiCCO = 0.88, AUC-SVVLiDCO = 0.78, AUC-PPVLiDCO = 0.89, AUC-SVVFloTrac = 0.87, AUC-PPVPhilips = 0.92 and AUC-PVI = 0.68. Optimal threshold values for prediction of fluid responsiveness ranged between 9.5 and 17.5%. Lowest threshold values were observed for SVVLiDCO, highest for PVI.ConclusionAll functional hemodynamic parameters tested except for PVI showed that their use allows a reliable identification of potential fluid responders. PVI however, may not be suitable after cardiac surgery to predict fluid responsiveness.Trial registrationNCT02571465, registered on October 7th, 2015 (retrospectively registered).

Practical impact of a decision support for goal-directed fluid therapy on protocol adherence: a clinical implementation study in patients undergoing major abdominal surgery.

The purpose of this study was to assess the effects of using a real time clinical decision-support system, "Assisted Fluid Management" (AFM), to guide goal-directed fluid therapy (GDFT) during major abdominal surgery. We compared a group of patients managed using the AFM system with a historical cohort of patients (control group) who had been managed using a manual GDFT strategy. Adherence to the protocol was defined as the relative intraoperative time spent with a stroke volume variation (SVV) < 13%. We hypothesised that patients in the AFM group would have more time during surgery with a SVV < 13% compared to the control group. All patients had a radial arterial line connected to a pulse contour analysis monitor and received a 2ml/kg/h maintenance crystalloid infusion. Additional 250ml crystalloid boluses were administered whenever measured SVV ≥ 13% in the control group, and when the software suggested a fluid bolus in the AFM group. We compared 46 AFM-guided patients to 38 controls. Patients in the AFM group spent significantly more time during surgery with a SVV < 13% compared to the control group (median 92% [82, 96] vs. 76% [54, 86]; P < 0.0005), and received less fluid overall (1775ml [1225, 2425] vs. 2350ml [1825, 3250]; P = 0.010). The incidence of postoperative complications was comparable in the two groups. Implementation of a decision support system for GDFT guidance resulted in a significantly longer period during surgery with a SVV < 13% with a reduced total amount of fluid administered. Trial registration: Clinical Trials.gov (NCT03141411).

Midazolam increases preload dependency during endotoxic shock in rabbits by affecting venous vascular tone

BackgroundSeptic patients often require sedation in intensive care unit, and midazolam is one of the most frequently used sedatives among them. But the interaction between midazolam and septic shock is not known. The aim of this study is to investigate the effects of midazolam on preload dependency in an endotoxic shock model by evaluating systemic vascular tone and cardiac function.MethodsEighteen rabbits were randomly divided into three groups: Control group, MID1 group and MID2 group. Rabbits underwent ketamine anaesthesia and mechanical ventilation, and haemodynamic assessments were recorded in three groups (T0). Endotoxic shock was induced by lipopolysaccharide intravenously, and fluid resuscitation and norepinephrine were administered to obtain the baseline mean arterial pressure (MAP) (T1). Rabbits received equivalent normal saline (Control) and two consecutive dosages of midazolam: 0.3 mg kg−1 h−1 (MID1) and 3 mg kg−1 h−1 (MID2) (T2). Rabbits received another round of fluid challenge and norepinephrine infusion to return the MAP to normal (T3).ResultsNo significant differences in haemodynamic parameters were observed in three groups at T0, T1 or T3. Midazolam infusion significantly increased pulse pressure variation (PPV) and stroke volume variation (SVV) compared to the values in Control group, and MAP, central venous pressure (CVP), mean systemic filling pressure (Pmsf) and cardiac output (CO) decreased at T2. Same effects were observed with increasing doses of midazolam, and resistance for venous return (Rvr) decreased (MID1 vs. MID2) at T2. PPV and SVV increased significantly at T2 compared to the values at T1. MAP, CVP, Pmsf and CO decreased in MID1 and MID2 groups. Rvr also decreased in MID2 group (T2 vs. T1). Midazolam did not affect cardiac function index, systemic vascular resistance or artery resistance (T2 vs. T1).ConclusionsMidazolam administration promoted preload dependency in septic shock models via decreased venous vascular tone without affecting cardiac function.

Comportamento da variação do volume sistólico em pacientes hemodinamicamente estáveis durante cirurgia torácica com períodos de ventilação monopulmonar

In last few years, emphasis was placed in goal-directed therapy in order to optimize patient's hemodynamic status and improve their prognosis. Parameters based on the interaction between heart and lungs have been questioned in situations like low tidal volume and open chest surgery. The goal of the study was to analyze the changes that one-lung ventilation can produce over stroke volume variation and to assess the possible impact of airway pressures and lung compliance over stroke volume variation.Prospective observational study, 112 patients undergoing lung resection surgery with one-lung ventilation periods were included. Intravenous fluid therapy with crystalloids was set at 2mL.kg-1.h-1. Hypotension episodes were treated with vasoconstrictive drugs. Two-lung ventilation was implemented with a TV of 8mL.kg-1 and one-lung ventilation was managed with a TV of 6mL.kg-1. Invasive blood pressure was monitored. We recorded the following cardiorespiratory values: heart rate, mean arterial pressure, cardiac index, stroke volume index, airway peak pressure, airway plateau pressure and static lung compliance at 3 different times during surgery: immediately after lung collapse, 30minutes after initiating one-lung ventilation and after restoration of two-lung ventilation.Stroke volume variation values were influenced by lung collapse (before lung collapse14.6 (DS) vs. OLV 9.9% (DS), p < 0.0001); or after restoring two-lung ventilation (11.01 (DS), p < 0.0001). During two-lung ventilation there was a significant correlation between airwaypressures and stroke volume variation, however this correlation lacks during one-lung ventilation.The decrease of stroke volume variation values during one-lung ventilation with protective ventilatory strategies advices not to use the same threshold values to determine fluid responsiveness.

Intraoperative hemodynamics monitoring in a patient with pheochromocytoma multisystem crisis: a case report

BackgroundPheochromocytoma is a rare catecholamine-secreting tumor. To evaluate the intraoperative hemodynamics with precision is difficult.Case presentationA 42-year-old man, who suddenly developed a life-threatening pheochromocytoma multisystem crisis that occurred during preoperative prophylactic medication, underwent urgent bilateral adrenalectomy. For the purpose of evaluating the intraoperative hemodynamics, we monitored both pulmonary artery catheter-based cardiac output (PACO) and arterial pressure-based cardiac output (APCO; FloTrac™). APCO fluctuated in poor agreement with the change in PACO, especially in the state of cytokine storming.ConclusionsOverall, the value of stroke volume variation derived from FloTrac™ changed in tandem with the intraoperative volume status, indicating its utility as a marker of circulatory hemodynamics.

Effect of two- or four-hour oral intake restriction on intraoperative intravascular volume optimization using stroke volume variation analysis: a single-blinded randomized controlled trial.

Effect of two- or four-hour oral intake restriction on intraoperative intravascular volume optimization using stroke volume variation analysis: a single-blinded randomized controlled trial.

Hemodynamic effects of different types of pneumatic compression of the lower extremities during anesthesia induction: a prospective randomized controlled trial.

BackgroundThe current study evaluated the hemodynamic effects of different types of pneumatic compressions of the lower extremities during anesthesia induction. In addition, the hemodynamic effects were compared between patients older than 65 age years and those aged 65 years or younger.MethodsOne hundred and eighty patients (90: > 65 years and 90: ≤ 65 years) were enrolled. Each age group of patients was randomly assigned to one of three groups; Group 1 (no compression), Group 2 (sequential pneumatic compression), and Group 3 (sustained pneumatic compression without decompression). Invasive blood pressure, cardiac index (CI), and stroke volume variation (SVV) were measured.ResultsIn patients aged ≤ 65 years, mean arterial pressure (MAP) and CI were significantly higher and SVV was lower in Group 3 compared to Group 1 before tracheal intubation, but there were no differences between Groups 1 and 2. However, there were no differences in MAP, CI, and SVV among the three groups in patients aged > 65 years. The number of patients who showed a MAP < 60 mmHg was less in Group 3 than Group 1 in patients aged ≤ 65 years, but not in patients aged > 65 years.ConclusionsSustained pneumatic compression of the lower extremities has more hemodynamic stabilizing effects compared to sequential compression during anesthesia induction in patients aged 65 years or younger. However, no difference between methods of compression was observed in patients older than 65 years.

Comparison of Proaqt/Pulsioflex® and oesophageal Doppler for intraoperative haemodynamic monitoring during intermediate-risk abdominal surgery

ObjectiveTo compare cardiac index (CI) between Proaqt/PulsioFlex® and oesophageal Doppler (OD) and the ability of the PulsioFlex® to track CI changes induced by fluid challenge and secondly to assess the impact of the time interval between two auto-calibrations of PulsioFlex® on the accuracy of the measured CI. MethodsIn a single hospital, 49 intermediate-risk oncologic abdominal surgery patients were included in an observational study. We measured the cardiac Index (CI) provided by OD and by the Proaqt/PulsioFlex® before and after internal calibration, which were performed randomly at specific intervals after the initial one (30, 60, 90 and 120min). The ability to track fluid responsiveness was evaluated by measuring stroke volume variation, pulse pressure variation (PPV) and CI before and after a 250ml fluid challenge and assessed by a receiver operating characteristic curve analysis. ResultsThe percentages of error before calibration were 51, 58, 82, 81% for 30, 60, 90 and 120min, they were 39, 57, 65, and 54% after calibration. Trending ability is assumed by a 93% concordance rate after applying a 15% exclusion zone. The trend interchangeability rate was 13.75%. The area under the curve for fluid responsiveness measured by PPV and SVV PulsioFlex were respectively 0.67 [0.57–0.77], P<0.01 and 0.75 [0.47–0.66], which was not clinically relevant. ConclusionsThe Proaqt/Pulsioflex® system is not equivalent to OD for haemodynamic monitoring during non-vascular abdominal surgery in intermediate-risk patients. More studies are required to define the effect of the auto-calibration on the system.

The Correlation Between CVP and SVV and Intraoperative Minimal Blood Loss in Living Donor Hepatectomy

BackgroundBlood loss during liver surgery is found to be correlated with central venous pressure (CVP). The aim of the current retrospective study is to find out the cutoff value of CVP and stroke volume variation (SVV), which may increase the risk of having intraoperative blood loss of more than 100 mL during living liver donor hepatectomies. Method and PatientsTwenty-seven adult living liver donors were divided into 2 groups according to whether they had intraoperative blood loss of less (G1) or more than 100 mL (G2). The mean values of the patients' CVP and SVV at the beginning of the transaction of the liver parenchyma was used as the cutoff point. Its correlation to intraoperative blood loss was evaluated using the χ2 test; P < .001 was regarded as significant. ResultsThe cutoff points of CVP and SVV were 8 mm Hg and 13% respectively. The odds ratio of having blood loss exceeding 100 mL was 91.25 (P < .001) and 0.36 (P < .001) for CVP and SVV, respectively. ConclusionCVP less than 5 mm Hg, as suggested by most authors, is not always clinical achievable. Our results show that a value of less than 8 mm Hg or SVV 13% is able to achieve a minimal blood loss of 100 mL during parenchyma transaction during a living donor hepatectomy. Measurements used to lower the CVP or increased SVV in our serial were intravenous fluids restriction and the use of a diuretic.

Effect of goal-directed haemodynamic therapy in free flap reconstruction for head and neck cancer.

In free flap reconstruction for head and neck cancer, achieving a haemodynamic target using excessive fluid infusion is associated with decreased flap survival rates and extended hospital stays. We hypothesized that goal-directed haemodynamic therapy would improve flap survival rates and shorten hospitalization periods. Patients scheduled for free flap reconstruction were randomly assigned to a goal-directed haemodynamic therapy group (n = 31) or a conventional haemodynamic therapy control group (n = 31). The control group received extra bolus fluid and ephedrine or norepinephrine to maintain a mean arterial pressure ≥ 65 mmHg. The goal-directed haemodynamic therapy group received a colloid solution as the extra bolus fluid to maintain a stroke volume variation < 12%; dobutamine, ephedrine, or norepinephrine was administered to maintain a cardiac index ≥ 2.5 l/min/m2 and mean arterial pressure ≥ 65 mmHg. Enhanced recovery after surgery protocols were not used except for fluid therapy. An otolaryngologist blinded to group assignments assessed flap outcomes and classified them as 'survival,' 'at risk' or 'failure.' The hospitalization period was not significantly different between the groups. The goal-directed haemodynamic therapy group had significantly shorter intensive care unit stays and a higher flap survival rate. The crystalloid volume was significantly lower in goal-directed haemodynamic therapy group. Reoperation rates, post-operative complications, and laboratory data including inflammatory markers were similar between the groups. Compared to conventional haemodynamic therapy, goal-directed haemodynamic therapy does not reduce hospitalization periods; it may, however, reduce the length of intensive care unit stays and increase flap survival rates. Further studies including multi-centre trials with larger sample sizes are warranted.

Phenylephrine increases cardiac output by raising cardiac preload in patients with anesthesia induced hypotension

Induction of general anesthesia frequently induces arterial hypotension, which is often treated with a vasopressor, such as phenylephrine. As a pure α-agonist, phenylephrine is conventionally considered to solely induce arterial vasoconstriction and thus increase cardiac afterload but not cardiac preload. In specific circumstances, however, phenylephrine may also contribute to an increase in venous return and thus cardiac output (CO). The aim of this study is to describe the initial time course of the effects of phenylephrine on various hemodynamic variables and to evaluate the ability of advanced hemodynamic monitoring to quantify these changes through different hemodynamic variables. In 24 patients, after induction of anesthesia, during the period before surgical stimulus, phenylephrine 2 µg kg−1 was administered when the MAP dropped below 80% of the awake state baseline value for > 3 min. The mean arterial blood pressure (MAP), heart rate (HR), end-tidal CO2 (EtCO2), central venous pressure (CVP), stroke volume (SV), CO, pulse pressure variation (PPV), stroke volume variation (SVV) and systemic vascular resistance (SVR) were recorded continuously. The values at the moment before administration of phenylephrine and 5(T5) and 10(T10) min thereafter were compared. After phenylephrine, the mean(SD) MAP, SV, CO, CVP and EtCO2 increased by 34(13) mmHg, 11(9) mL, 1.02(0.74) L min−1, 3(2.6) mmHg and 4.0(1.6) mmHg at T5 respectively, while both dynamic preload variables decreased: PPV dropped from 20% at baseline to 9% at T5 and to 13% at T10 and SVV from 19 to 11 and 14%, respectively. Initially, the increase in MAP was perfectly aligned with the increase in SVR, until 150 s after the initial increase in MAP, when both curves started to dissociate. The dissociation of the evolution of MAP and SVR, together with the changes in PPV, CVP, EtCO2 and CO indicate that in patients with anesthesia-induced hypotension, phenylephrine increases the CO by virtue of an increase in cardiac preload.

Issues of Immunological and Hemodynamic Monitoring Before and During Kidney Transplantation in Sensitized Heart Transplant Recipient

Previously transplanted highly sensitized patients experience problems with subsequent transplantation. It is also difficult to provide optimal hemodynamic conditions during successive kidney transplantation in heart transplant recipients. Patient and methodsWe present a case of a 56-year old patient with end-stage renal failure after heart transplantation performed 21 years ago and hemodialyzed using arteriovenous fistula. The patient had 69% panel-reactive antibodies, had been on the active waiting list since 2013, and presented 335 positive crossmatches with deceased donors. He also positively crossmatched with a potential living donor. Detailed examination of anti-HLA antibodies revealed the absence of IgG donor-specific antibodies and negative crossmatch with dithiothreitol-treated serum. The transplantation from his wife was performed with positive crossmatch after 4 plasma exchanges and thymoglobulin induction. Because sympathetic and parasympathetic denervation of the transplanted heart and the presence of arteriovenous fistula induced volume overload of the right heart, we used central venous pressure (CVP) and the PiCCO2 for postsurgical assessment of cardiac output. ResultsMonitoring, like CVP and other static exponents of preload obtained by PICCO (extravascular lung water, global end-diastolic volume index) as well as the dynamic parameters obtained by PiCCO2 (pulse pressure variation, stroke volume variation), was not sensitive enough to describe recipient volume status. The immediate graft function was observed, and after 11 months satisfactory estimated glomerular filtration rate is noted with the absence of donor-specific antibodies. ConclusionThe history of heart transplantation with existing arteriovenous fistula makes clinical tools such as continuous cardiac output monitoring and CVP parameter inadequate for describing the hemodynamic situation. The high level of panel-reactive antibodies and positive crossmatch possibly caused by IgM antibodies do not have to withdraw the recipient from kidney transplantation.

Influence of stroke volume variation on fluid treatment and postoperative complications in thoracic surgery.

BackgroundFluid management in critically ill patients usually relies on increasing preload to augment cardiac output. In the present study, we aimed to evaluate whether stroke volume variation (SVV) can guide fluid therapy and reduce complications.Patients and methodsIn this retrospective study, a total of 88 patients who underwent lobectomy were divided into two groups: group 1 (SVV, n=43) and group 2 (conventional or central venous pressure [CVP], n=45). Heart rate, blood pressure, oxygen saturation, SVV (only group 1), CVP (all patients), urea, creatinine, and hemoglobin levels before and after surgery, use of fluid, blood and inotropic agents, and postoperative complications were recorded retrospectively.ResultsThe mean age of the study population was 56.9±14.4 years and 75% of the patients were male. SVV was used in fluid therapy in 48.9% of the patients. The use of SVV resulted in an increased use of crystalloids and colloids with increased urine output per hour (p<0.05). Of patients in the SVV group and the CVP group, 44.1% and 51.1% developed at least one complication, respectively (p=0.531). The rate of respiratory complications including atelectasis, pneumonia, hypoxemia, and an increased production of secretions was 21% in the SVV group and 37.7% in the CVP group (p=0.104). The rate of complications and the length of hospital stay were comparable between the groups (p>0.05).ConclusionOur study results showed that the use of SVV increased the use of crystalloids and colloids and favorably affected urine output per hour but did not reduce complications in thoracic surgery.

Variability of peripheral arterial peak velocity predicts fluid responsiveness in patients with septic shock

To explore the accuracy of fluid responsiveness assessment by variability of peripheral arterial peak velocity and variability of inferior vena cava diameter (ΔIVC) in patients with septic shock. A prospective study was conducted. The patients with septic shock undergoing mechanical ventilation (MV) admitted to intensive care unit (ICU) of Beijing Electric Power Hospital from January 2016 to December 2017 were enrolled. According to sepsis bundles of septic shock, volume expansion (VE) was conducted. The increase in cardiac index (ΔCI) after VE ≥ 10% was defined as liquid reaction positive (responsive group), ΔCI < 10% was defined as the liquid reaction negative (non-responsive group). The hemodynamic parameters [central venous pressure (CVP), intrathoracic blood volume index (ITBVI), stroke volume variation (SVV), ΔIVC, variability of carotid Doppler peak velocity (ΔCDPV), and variability of brachial artery peak velocity (ΔVpeak-BA)] before and after VE were monitored. The correlations between the hemodynamic parameters and ΔCI were explored by Pearson correlation analysis. Receiver operating characteristic (ROC) curve was plotted to analyze the predictive value of all hemodynamic parameters on fluid responsiveness. During the study, 74 patients with septic shock were included, of whom 9 were excluded because of peripheral artery stenosis, recurrent arrhythmia or abdominal distension influencing the ultrasound examination, and 65 patients were finally enrolled in the analysis. There were 31 patients in the responsive group and 34 in the non-responsive group. SVV, ΔIVC, ΔCDPV and ΔVpeak-BA before VE in responsive group were significantly higher than those of the non-responsive group [SVV: (12.3±2.4)% vs. (9.2±2.1)%, ΔIVC: (22.3±5.3)% vs. (15.5±3.7)%, ΔCDPV: (15.3±3.3)% vs. (10.3±2.4)%, ΔVpeak-BA: (14.5±3.3)% vs. (9.6±2.3)%, all P < 0.05]. There was no significant difference in CVP [mmHg (1 mmHg = 0.133 kPa): 7.5±2.5 vs. 8.2±2.6] or ITBVI (mL/m2: 875.2±173.2 vs. 853.2±192.0) between the responsive group and non-responsive group (both P > 0.05). There was no significant difference in hemodynamic parameter after VE between the two groups. Correlation analysis showed that SVV, ΔIVC, ΔCDPV, and ΔVpeak-BA before VE showed significant linearity correlation with ΔCI (r value was 0.832, 0.813, 0.854, and 0.814, respectively, all P < 0.05), but no correlation was found between CVP and ΔCI (r = -0.342, P > 0.05) as well as ITBVI and ΔCI (r = -0.338, P > 0.05). ROC curve analysis showed that the area under ROC curve (AUC) of SVV, ΔIVC, ΔCDPV, and ΔVpeak-BA before VE for predicting fluid responsiveness was 0.857, 0.826, 0.906, and 0.866, respectively, which was significantly higher than that of CVP (AUC = 0.611) and ITBVI (AUC = 0.679). When the optimal cut-off value of SVV for predicting fluid responsiveness was 11.5%, the sensitivity was 70.4%, and the specificity was 94.7%. When the optimal cut-off value of ΔIVC was 20.5%, the sensitivity was 60.3%, and the specificity was 89.7%. When the optimal cut-off value of ΔCDPV was 13.0%, the sensitivity was 75.2%, and the specificity was 94.9%. When the optimal cut-off value of ΔVpeak-BA was 12.7%, the sensitivity was 64.8%, and the specificity was 89.7%. Ultrasound assessment of ΔIVC, ΔCDPV, and ΔVpeak-BA could predict fluid responsiveness in patients with septic shock receiving mechanical ventilation. ΔCDPV had the highest predictive value among these parameters.

Positive end-expiratory pressure-induced increase in external jugular venous pressure does not predict fluid responsiveness in laparoscopic prostatectomy.

Dynamic change in central venous pressure (CVP) was associated with fluid responsiveness. External jugular venous pressure (EJVP) may reliably estimate CVP and have the advantages of being less invasive. We investigated whether increase in EJVP induced by positive end-expiratory pressure (PEEP) could be a reliable predictor of fluid responsiveness in patients undergoing robot-assisted laparoscopic prostatectomy (RALP). Fifty patients who underwent RALP with steep Trendelenburg position were enrolled. PEEP of 10cmH2O was applied for 5min and then 300ml of colloid was administered. EJVP, stroke volume variation (SVV), and cardiac index calculated by pulse contour method were measured before and after the PEEP challenge and colloid administration. Increase in cardiac index>10% was used to define the fluid responsiveness. Twenty-six patients were fluid responders. Neither the increase in EJVP after the initial PEEP nor SVV was significantly different between responders and non-responders. They were not significantly correlated with an increase in cardiac index. The areas under the receiver operating characteristic curve (AUC) of these two variables were not significantly greater than 0.5. However, a post hoc analysis revealed that AUC of a decrease in EJVP after removal of PEEP was significantly greater than 0.50. Our study results suggested that SVV and increase in EJVP after applying PEEP were not accurate predictors of fluid responsiveness during RALP. Further studies are required to find an adequate preload index in robot-assisted urologic surgery with steep Trendelenburg position.

Goal-Directed Fluid Resuscitation Protocol Based on Arterial Waveform Analysis of Major Burn Patients in a Mass Burn Casualty

Adequate fluid titration during the initial resuscitation period of major burn patients is crucial. This study aimed to evaluate the feasibility and efficacy of a goal-directed fluid resuscitation protocol that used hourly urine output plus the arterial waveform analysis FloTrac (Edwards LifeSciences, Irvine, Calif) system for major burns to avoid fluid overload. We conducted a retrospective cohort study of 43 major burn patients at the Tri-Service General Hospital after the Formosa Fun Coast Dust Explosion on June 27, 2015. Because of the limited capacity of intensive care units (ICUs), 23 intubated patients were transferred from the burn wards or emergency department to the ICU within 24 hours. Fluid administration was adjusted to achieve a urine output of 30 to 50 mL/h, cardiac index greater than 2.5 L/min/m, and stroke volume variation (SVV) less than 12%. The hourly crystalloid fluid infusion rate was titrated based on SVV and hourly urine output. Of the 23 critically burned patients admitted to the ICU, 13 patients who followed the goal-directed fluid resuscitation protocol within 12 hours postburn were included in the analysis. The mean age (years) was 21.8, and the mean total body surface area (TBSA) burned (%) was 68.0. The mean Revised Baux score was 106.8. All patients sustained inhalation injury. The fluid volumes administered to patients in the first 24 hours and the second 24 hours (mL/kg/% total body surface area) were 3.62 ± 1.23 and 2.89 ± 0.79, respectively. The urine outputs in the first 24 hours and the second 24 hours (mL/kg/h) were 1.13 ± 0.66 and 1.53 ± 0.87, respectively. All patients achieved the established goals within 32 hours postburn. In-hospital mortality rate was 0%. The SVV-based goal-directed fluid resuscitation protocol leads to less unnecessary fluid administration during the early resuscitation phase. Clinicians can efficaciously manage the dynamic body fluid changes in major burn patients under the guidance of the protocol.

Perioperative Goal-Directed Therapy Using Invasive Uncalibrated Pulse Contour Analysis

“Perioperative goal-directed therapy” (PGDT) aims at an optimization of basic and advanced global hemodynamic variables to maintain adequate oxygen delivery to the end-organs. PGDT protocols help to titrate fluids, vasopressors, or inotropes to hemodynamic target values. There is considerable evidence that PGDT can improve patient outcome in high-risk patients if both fluids and inotropes are administered to target hemodynamic variables reflecting blood flow. Despite this evidence, PGDT strategies aiming at an optimization of blood flow seem to be not well implemented in routine clinical care. The analysis of the arterial blood pressure waveform using invasive uncalibrated pulse contour analysis can be used to assess hemodynamic variables used in PGDT protocols. Pulse contour analysis allows the assessment of stroke volume (SV)/cardiac output (CO) and pulse pressure variation (PPV)/stroke volume variation (SVV) and thus helps to titrate fluids and vasoactive agents based on principles of “functional hemodynamic monitoring.” Pulse contour analysis-based PGDT treatment algorithms can be classified according to the hemodynamic variables they use as targets: PPV/SVV, SV/CO, or a combination of these variables. From a physiologic point of view, algorithms using both dynamic cardiac preload and blood flow variables as hemodynamic targets might be most effective in improving patient outcome. Future research should focus on the improvement of hemodynamic treatment algorithms and on the identification of patient subgroups in which PGDT based on uncalibrated pulse contour analysis can improve patient outcome.

Stroke volume variation and serum creatinine changes during abdominal aortic aneurysm surgery: a time-integrated analysis.

Patients undergoing abdominal aortic aneurysm (AAA) surgery with suprarenal clamping are at high risk for acute kidney injury (AKI) and major cardiac and cerebrovascular events (MACCE). We aimed to assess whether the stroke volume variation (SVV), a measure of hemodynamic instability, is associated with AKI in hypertensive patients undergoing elective AAA surgery with suprarenal clamping. In a cohort of 51 hypertensive patients, we performed serial measurements of SVV (n = 459) and serum creatinine (sCr) (n = 255). AKI was defined according to the KDIGO clinical practice guidelines. Data were analyzed by repeated-measures ANOVA and regression analysis of time-integrated changes of both SVV and sCr. AKI developed in 45% of patients (stage 1: 31%; stage 2: 10%; stage 3: 2%). The diuresis during surgery (beta - 0.29 Z-score 95% [CI -0.54, -0.05]; p = 0.02), clamp time (beta 0.29 Z-score [0.05-0.52]; p = 0.02), and time-integrated changes in SVV from baseline to 12h after surgery (beta 0.31 Z-score [0.03-0.60]; p = 0.03) were independent predictors of the time-integrated changes in sCr from baseline to 48h after the end of surgery. In a model adjusted for age and sex, patients with AKI had an increased risk for MACCE during a mean follow-up of 3.5 ± 1.1years (HR 5.53 [1.52-20.06]; p = 0.004). SVV increases progressively during and after AAA surgery in subjects who will develop AKI. The increase of SVV precedes and predicts the rise in sCr and is a good discriminator of the development of AKI. AKI is associated with an increased long-term risk for MACCE.