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Background: Escherichia coli is the most common cause of human bloodstream infections and bacterial sepsis/septic shock. However, translation of preclinical septic shock resuscitative therapies remains limited mainly due to low-fidelity of available models in mimicking clinical illness. To overcome the translational barrier, we sought to replicate sepsis complexity by creating an acutely critically-ill preclinical bacterial septic shock model undergoing active 48-h intensive care management. Aim: To develop a clinically relevant large-animal (ovine) live-bacterial infusion model for septic shock. Methods: Septic shock was induced by intravenous infusion of the live antibiotic resistant extra-intestinal pathogenic E. coli sequence type 131 strain EC958 in eight anesthetised and mechanically ventilated sheep. A bacterial dose range of 2 × 105–2 × 109 cfu/mL was used for the dose optimisation phase (n = 4) and upon dose confirmation the model was developed (n = 5). Post-shock the animals underwent an early-vasopressor and volume-restriction resuscitation strategy with active haemodynamic management and monitoring over 48 h. Serial blood samples were collected for testing of pro-inflammatory (IL-6, IL-8, VEGFA) and anti-inflammatory (IL-10) cytokines and hyaluronan assay to assess endothelial integrity. Tissue samples were collected for histopathology and transmission electron microscopy. Results: The 2 × 107 cfu/mL bacterial dose led to a reproducible distributive shock within a pre-determined 12-h period. Five sheep were used to demonstrate consistency of the model. Bacterial infusion led to development of septic shock in all animals. The baseline mean arterial blood pressure reduced from a median of 91 mmHg (71, 102) to 50 mmHg (48, 57) (p = 0.004) and lactate levels increased from a median of 0.5 mM (0.3, 0.8) to 2.1 mM (2.0, 2.3) (p = 0.02) post-shock. The baseline median hyaluronan levels increased significantly from 25 ng/mL (18, 86) to 168 ng/mL (86, 569), p = 0.05 but not the median vasopressor dependency index which increased within 1 h of resuscitation from zero to 0.39 mmHg−1 (0.06, 5.13), p = 0.065, and. Over the 48 h, there was a significant decrease in the systemic vascular resistance index (F = 7.46, p = 0.01) and increase in the pro-inflammatory cytokines [IL-6 (F = 8.90, p = 0.02), IL-8 (F = 5.28, p = 0.03), and VEGFA (F = 6.47, p = 0.02)]. Conclusions: This critically ill large-animal model was consistent in reproducing septic shock and will be applied in investigating advanced resuscitation and therapeutic interventions. [ABSTRACT FROM AUTHOR]

Haemodynamic monitoring and management are cornerstones of perioperative care. The goal of haemodynamic management is to maintain organ function by ensuring adequate perfusion pressure, blood flow, and oxygen delivery. We here present guidelines on "Intraoperative haemodynamic monitoring and management of adults having non-cardiac surgery" that were prepared by 18 experts on behalf of the German Society of Anaesthesiology and Intensive Care Medicine (Deutsche Gesellschaft für Anästhesiologie und lntensivmedizin; DGAI). [ABSTRACT FROM AUTHOR]

During surgery, various haemodynamic variables are monitored and optimised to maintain organ perfusion pressure and oxygen delivery – and to eventually improve outcomes. Important haemodynamic variables that provide an understanding of most pathophysiologic haemodynamic conditions during surgery include heart rate, arterial pressure, central venous pressure, pulse pressure variation/stroke volume variation, stroke volume, and cardiac output. A basic physiologic and pathophysiologic understanding of these haemodynamic variables and the corresponding monitoring methods is essential. We therefore revisit the pathophysiologic rationale for intraoperative monitoring of haemodynamic variables, describe the history, current use, and future technological developments of monitoring methods, and finally briefly summarise the evidence that haemodynamic management can improve patient-centred outcomes. [ABSTRACT FROM AUTHOR]

Background: Patients undergoing high-risk surgery show haemodynamic instability and an increased risk of morbidity. However, most of the available data concentrate on the intraoperative period. This study aims to characterise patients with advanced haemodynamic monitoring throughout the whole perioperative period using electrical cardiometry. Methods: In a prospective, observational, monocentric pilot study, electrical cardiometry measurements were obtained using an Osypka ICON™ monitor before surgery, during surgery, and repeatedly throughout the hospital stay for 30 patients with primary ovarian cancer undergoing multivisceral cytoreductive surgery. Severe postoperative complications according to the Clavien–Dindo classification were used as a grouping criterion. Results: The relative change from the baseline to the first intraoperative timepoint showed a reduced heart rate (HR, median – 19 [25-quartile − 26%; 75-quartile − 10%]%, p < 0.0001), stroke volume index (SVI, − 9.5 [− 15.3; 3.2]%, p = 0.0038), cardiac index (CI, − 24.5 [− 32; − 13]%, p < 0.0001) and index of contractility (− 17.5 [− 35.3; − 0.8]%, p < 0.0001). Throughout the perioperative course, patients had intraoperatively a reduced HR and CI (both p < 0.0001) and postoperatively an increased HR (p < 0.0001) and CI (p = 0.016), whereas SVI was unchanged. Thoracic fluid volume increased continuously versus preoperative values and did not normalise up to the day of discharge. Patients having postoperative complications showed a lower index of contractility (p = 0.0435) and a higher systolic time ratio (p = 0.0008) over the perioperative course in comparison to patients without complications, whereas the CI (p = 0.3337) was comparable between groups. One patient had to be excluded from data analysis for not receiving the planned surgery. Conclusions: Substantial decreases in HR, SVI, CI, and index of contractility occurred from the day before surgery to the first intraoperative timepoint. HR and CI were altered throughout the perioperative course. Patients with postoperative complications differed from patients without complications in the markers of cardiac function, a lower index of contractility and a lower SVI. The analyses of trends over the whole perioperative time course by using non-invasive technologies like EC seem to be useful to identify patients with altered haemodynamic parameters and therefore at an increased risk for postoperative complications after major surgery. [ABSTRACT FROM AUTHOR]

Prediction of fluid responsiveness is essential in perioperative goal directed therapy, but dynamic tests of fluid responsiveness are not applicable during open-chest surgery. We hypothesised that two methods could predict fluid responsiveness during cardiac surgery based on their ability to alter preload and thereby induce changes in arterial blood pressure characteristics: (1) the change caused by extrasystolic beats and (2) the change caused by a fast infusion of 50 ml crystalloid (micro-fluid challenge). Arterial blood pressure and electrocardiogram waveforms were collected during surgical preparation of the left internal mammary artery in patients undergoing coronary artery bypass surgery. Patients received a fluid challenge (5 ml/kg ideal body weight). The first 50 ml were infused in 10 s and comprised the micro-fluid challenge. Predictor variables were defined as post-ectopic beat changes (compared with sinus beats preceding ectopy) in arterial blood pressure characteristics, such as pulse pressure and systolic pressure, or micro-fluid challenge induced changes in the same blood pressure characteristics. Patients were considered fluid responsive if stroke volume index increased by 15% or more after the full fluid challenge. Diagnostic accuracy was calculated by the area under the receiver operating characteristics curve (AUC). Fifty-six patients were included for statistical analysis. Thirty-one had extrasystoles. The maximal AUC was found for the extrasystolic change in pulse pressure and was 0.70 (CI [0.35 to 1.00]). The micro-fluid challenge method generally produced lower AUC point estimates. Extrasystoles did not predict fluid responsiveness with convincing accuracy in patients undergoing cardiac surgery and changes in arterial waveform indices following a micro-fluid challenge could not predict fluid responsiveness. Given a low number of fluid responders and inherently reduced statistical power, our data does not support firm conclusions about the utility of the extrasystolic method. Clinical Trial Registration: Unique identifier: NCT02903316. https://clinicaltrials.gov/ct2/show/NCT02903316?cond=NCT02903316&rank=1. [ABSTRACT FROM AUTHOR]

This prospective study evaluates haemodynamic and electroencephalographic effects observed when administering four combinations of effect-site concentrations of propofol (CePROP) and remifentanil (CeREMI), all yielding a single predicted probability of tolerance of laryngoscopy of 90% (PTOL = 90%) according to the Bouillon interaction model. We aimed to identify combinations of CePROP and CeREMI along a single isobole of PTOL that result in favourable hypnotic and haemodynamic conditions. This knowledge could be of advantage in the development of drug advisory monitoring technology. 80 patients (18–90 years of age, ASA I–III) were randomized into four groups and titrated towards CePROP (Schnider model, ug⋅ml−1) and CeREMI (Minto model, ng⋅ml−1) of respectively 8.6 and 1, 5.9 and 2, 3.6 and 4 and 2.0 and 8. After eleven minutes of equilibration, baseline measurements of haemodynamic endpoints and bispectral index were compared with three minutes of responsiveness measurements after laryngoscopy. Before laryngoscopy, bispectral index differed significantly (p < 0.0001) between groups in concordance with CePROP. Heart rate decreased with increasing CeREMI (p = 0.001). The haemodynamic and arousal responses evoked by laryngoscopy were not significantly different between groups, but CePROP = 3.6 μg⋅ml−1 and CeREMI = 4 ng⋅ml−1 evoked the lowest median value for ∆HR and ∆SAP after laryngoscopy. This study provides clinical insight on the haemodynamic and hypnotic consequences, when a model based predicted PTOL is used as a target for combined effect-site controlled target- controlled infusion of propofol and remifentanil. Heart rate and bispectral index were significantly different between groups despite a theoretical equipotency for PTOL, suggesting that each component of the anaesthetic state (immobility, analgesia, and hypnotic drug effect) should be considered as independent neurophysiological and pharmacological phenomena. However, claims of (in)accuracy of the predicted PTOL must be considered preliminary because larger numbers of observations are required for that goal. [ABSTRACT FROM AUTHOR]

Stable intraoperative haemodynamics are associated with improved outcome and even short periods of instability are associated with an increased risk of complications. During anaesthesia intermittent non-invasive blood pressure and heart rate remains the cornerstone of haemodynamic monitoring. Continuous monitoring of systemic blood pressure or even -flow requires invasive or advanced modalities creating a barrier for obtaining important real-time haemodynamic insight. The Peripheral Perfusion Index (PPI) is obtained continuously and non-invasively by standard photoplethysmography. We hypothesized that changes in indices of systemic blood flow during general anaesthesia would be reflected in the PPI. PPI, stroke volume (SV), cardiac output (CO) and mean arterial pressure (MAP) were evaluated in 20 patients. During general anaesthesia but before start of surgery relative changes of SV, CO and MAP were compared to the relative changes of PPI induced by head-up (HUT) and head-down tilt (HDT). Furthermore, the effect of phenylephrine (PE) during HUT on these parameters was investigated. ∆PPI correlated significantly (p < 0.001) with ∆SV (r = 0.9), ∆CO (r = 0.9), and ∆MAP (r = 0.9). HUT following induction of anaesthesia resulted in a decrease in PPI of 41% (25-52) [median (IQR)], SV 27% (23-31), CO 27% (25-35), and MAP 28% (22-35). HDT led to an increase in PPI of 203% (120-375), SV of 29% (21-41), CO 22% (16-34), and MAP 47% (42-60). After stabilizing a second HUT decreased PPI 59% (49-76), SV 33% (28-37), CO 31% (28-36), and MAP 34% (26-38). Restoration of preload with PE increased PPI by 607% (218-1078), SV by 96% (82-116), CO by 65% (56-99), and MAP by 114% (83-147). During general anaesthesia changes in PPI tracked changes in systemic haemodynamics. [ABSTRACT FROM AUTHOR]

Background: We performed a systematic review and meta-analysis of studies assessing the end-expiratory occlusion test (EEXPO test)-induced changes in cardiac output (CO) measured by any haemodynamic monitoring device, as indicators of preload responsiveness. Methods: MEDLINE, EMBASE and Cochrane Database were screened for original articles. Bivariate random-effects meta-analysis determined the Area under the Summary Receiver Operating Characteristic (AUSROC) curve of EEXPO test-induced changes in CO to detect preload responsiveness, as well as pooled sensitivity and specificity and the best diagnostic threshold. Results: Thirteen studies (530 patients) were included. Nine studies were performed in the intensive care unit and four in the operating room. The pooled sensitivity and the pooled specificity for the EEXPO test-induced changes in CO were 0.85 [0.77–0.91] and 0.88 [0.83–0.91], respectively. The AUSROC curve was 0.91 [0.86–0.94] with the best threshold of CO increase at 5.1 ± 0.2%. The accuracy of the test was not different when changes in CO were monitored through pulse contour analysis compared to other methods (AUSROC: 0.93 [0.91–0.95] vs. 0.87 [0.82–0.96], respectively, p = 0.62). Also, it was not different in studies in which the tidal volume was ≤ 7 mL/kg compared to the remaining ones (AUSROC: 0.96 [0.92–0.97] vs. 0.89 [0.82–0.95] respectively, p = 0.44). Subgroup analyses identified one possible source of heterogeneity. Conclusions: EEXPO test-induced changes in CO reliably detect preload responsiveness. The diagnostic performance is not influenced by the method used to track the EEXPO test-induced changes in CO. Trial registration The study protocol was prospectively registered on PROSPERO: CRD42019138265. [ABSTRACT FROM AUTHOR]

This study aims to determine whether the use of remote monitoring (RM) in implantable cardiac devices decreases all-cause mortality and heart failure (HF)-related hospitalization. We sought to conduct a systematic review and a meta-analysis of published randomized controlled studies. The population is adult patients with a diagnosis of HF with implantable devices. The intervention is RM using implantable cardiac devices whether added or used alone compared to standard of care. The outcomes are HF-related hospitalization and all-cause mortality. Risk of bias was assessed using the criteria defined in the Revised Cochrane Collaboration's tool for assessment of risk of bias. Data were extracted and validity was assessed independently by two reviewers. Electronic databases EMBASE and MEDLINE (Ovid) were searched up to 14th of October 2019, supplemented by a second search in CENTRAL (Cochrane Central Register of Controlled Trials) and clinicaltrials.gov. Only randomized controlled studies published in peer-reviewed journals with full format text in English of adult HF patients with a minimum follow-up of 6 months reporting mortality and/or hospitalization. Observational studies and studies that did not meet inclusion criteria were excluded. Thirteen randomized controlled studies that enrolled a total of 7015 patients were identified, 7 of which reported on all-cause mortality only and included 4460 patients. Compared with standard of care, the pooled relative risk (RR) of all-cause mortality and HF-related hospitalization in patients with RM compared to those receiving standard of care was 0.88 (95% confidence interval (CI) 0.69 to 1.11) and 0.95 (95% CI 0.78-1.16), respectively. In the subgroup analysis, using pulmonary pressure for RM was associated with a decrease in HF-related hospitalization (RR 0.73; 95% CI 0.60-0.88). RM showed benefit in reducing HF-related hospitalization when compared to standard of care only when using pulmonary pressure monitoring. [ABSTRACT FROM AUTHOR]

The Impella percutaneous mechanical circulatory support device is designed to augment cardiac output and reduce left ventricular wall stress and aims to improve survival in cases of cardiogenic shock. In this meta-analysis we investigated the haemodynamic effects of the Impella device in a clinical setting. We systematically searched all articles in PubMed/Medline and Embase up to July 2019. The primary outcomes were cardiac power (CP) and cardiac power index (CPI). Survival rates and other haemodynamic data were included as secondary outcomes. For the critical appraisal, we used a modified version of the U.S. Department of Health and Human Services quality assessment form. The systematic review included 12 studies with a total of 596 patients. In 258 patients the CP and/or CPI could be extracted. Our meta-analysis showed an increase of 0.39 W [95% confidence interval (CI): 0.24, 0.54], (p = 0.01) and 0.22 W/m2 (95% CI: 0.18, 0.26), (p < 0.01) for the CP and CPI, respectively. The overall survival rate was 56% (95% CI: 0.50, 0.62), (p = 0.09). The quality of the studies was moderate, mostly due to the presence of confounders. Our study suggests that in patients with cardiogenic shock, Impella support seems effective in augmenting CP(I). This study merely investigates the haemodynamic effectiveness of the Impella device and does not reflect the complete clinical impact for the patient. [ABSTRACT FROM AUTHOR]

Technologies for minimally-invasive cardiac output measurement in patients during surgery remain little used in routine practice. We tested a redeveloped system based on CO2 elimination (VCO2) by the lungs for use in ventilated patients, which can be seamlessly integrated into a modern anesthesia/monitoring platform, and provides automated, continuous breath-by-breath cardiac output monitoring. A prototype measurement system was constructed to measure VCO2 and end-tidal CO2 concentration with each breath. A baseline measurement of non-shunt cardiac output was made during a brief oscillating change in ventilator rate, according to the differential CO2 Fick approach and repeated at 5-10 min intervals. Continuous breath-by-breath monitoring of cardiac output was performed between these intervals from measurement of VCO2, using a derivation of the Fick equation applied to pulmonary CO2 elimination and cardiac output displayed in real time. Measurements were compared with simultaneous measurements by thermodilution in 50 patients undergoing cardiac surgery or liver transplantation. Overall mean bias [sd] for agreement in cardiac output measurement was - 0.3 [1.1] L/min, percentage error ± 38.7%, intraclass correlation coefficient = 0.91. Concordance in measurement of changes of at least 15% in cardiac output was 81.4%, with a mean angular bias of - 1.7°, and radial limits of agreement of ± 76.2° on polar plot analysis. The accuracy and precision compared favourably to other clinical techniques. The method is relatively seamless and automated and has potential for continuous, cardiac output monitoring in ventilated patients during anesthesia and critical care. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the accuracy and precision of non-invasive continuous blood pressure measurement by applanation tonometry (AT) in awake or anaesthetised cardiological intensive care patients. Patients suffering from highly impaired left ventricular function atrial fibrillation or severe aortic valve stenosis were included into the study. Arterial blood pressure was recorded by applanation tonometry (T-Line 400, Tensys Medical®, USA) and an arterial line in awake or anaesthetised patients. Discrepancies in mean (MAP), systolic (SAP), and diastolic (DAP) arterial pressure between the two methods were assessed as bias, limits of agreement and percentage error respectively. In 31 patients a total of 27,900 measurements were analyzed. The concordance correlation coefficient was 0.23, 0.45 and 0.06 for MAP, SAP and DAP, respectively. For all patients bias for MAPAT compared to MAPAL was 14.96 mmHg (SAPAT 4.51 mmHg; DAPAT 19.12 mmHg) with limits of agreement for MAPAT of 46.25 and - 16.33 mm Hg (SAPAT 48.00 and - 38.98 mmHg; DAPAT 50.12 and - 11.89 mmHg). Percentage error for MAPAT was 56.8% (42.7% for SAPAT; 75.2% for DAPAT). We conclude that the AT method is not reliable in ICU patients with severe cardiac comorbidities. [ABSTRACT FROM AUTHOR]

The measurement of cardiac output (CO) may be useful to improve the assessment of hemodynamics during simulated scenarios. The purpose of this study was to evaluate the feasibility of introducing an uncalibrated pulse contour device (MostCare, Vytech, Vygon, Padova, Italy) into the simulation environment. MostCare device was plugged to a clinical monitor and connected to the METI human patient simulator (HPS) to obtain a continuous arterial waveform analysis and CO calculation. In six different simulated clinical scenarios (baseline, ventricular failure, vasoplegic shock, hypertensive crisis, hypovolemic shock and aortic stenosis), the HPS-CO and the MostCare-CO were simultaneously recorded. The level of concordance between the two methods was assessed by the Bland and Altman analysis. 150-paired CO values were obtained. The HPS-CO values ranged from 2.3 to 6.6 L min-1 and the MostCare-CO values from 2.8 to 6.4 L min-1. The mean difference between HPS-CO and MostCare-CO was - 0.3 L min-1 and the limits of agreement were - 1.5 and 0.9 L min-1. The percentage of error was 23%. A good correlation between HPS-CO and MostCare-CO was observed in each scenario of the study (r = 0.88). Although MostCare-CO tended to underestimate the CO over the study period, good agreements were found between the two methods. Therefore, a pulse contour device can be integrated into the simulation environment, offering the opportunity to create new simulated clinical settings. [ABSTRACT FROM AUTHOR]

The oesophageal Doppler (OD) is a minimally invasive haemodynamic monitor used in the surgical theatre and the ICU. Using the OD, goal-directed therapy (GDT) has been shown to reduce perioperative complications in high-risk surgical patients. However, most GDT protocols currently in use are limited to stroke volume optimisation. In the present manuscript, we examine the conceptual models behind new OD-based measurements. These would provide the clinician with a comprehensive view of haemodynamic pathophysiology; including pre-load, contractility, and afterload. Specifically, volume status could be estimated using mean systemic filling pressure (MSFP), the pressure to which all intravascular pressures equilibrate during asystole. Using the OD, MSFP could be readily estimated by simultaneous measurements of aortic blood flow and arterial pressure with sequential manoeuvres of increasing airway pressure. This would result in subsequent reductions in cardiac output and arterial pressure and would allow for a linear extrapolation of a static MSFP value to a "zero flow" state. In addition, we also demonstrate that EF is proportional to mean blood flow velocity measured in the descending thoracic aorta with the OD. Furthermore, OD-derived indexes of blood flow velocity and acceleration, as well as force and kinetic energy, can be derived and used for continuous assessment of cardiac contractility at the bedside. Using OD-derived parameters, the different components of afterload: inertia, resistance and elastance, could also be individually determined. The integration of these additional haemodynamic parameters could assist the clinician in optimising and individualising haemodynamic performance in unstable patients. [ABSTRACT FROM AUTHOR]

Cardiac output measurement has a long history in haemodynamic management and many devices are now available with varying levels of accuracy. The purpose of the study was to compare the agreement and trending abilities of cardiac output, as measured by transpulmonary thermodilution and calibrated pulse contour analysis, using the VolumeView™ system, continuous thermodilution via a pulmonary artery catheter, and uncalibrated pulse contour analysis, using FloTrac™ with pulmonary artery bolus thermodilution. Twenty patients undergoing off-pump coronary artery bypass surgery using a pulmonary artery catheter and the VolumeView™ and FloTrac™ systems were included in this subgroup analysis of the cardiovascular anaesthesia registry at a single tertiary centre. During surgery, cardiac output was assessed after the induction of anaesthesia, after sternotomy, during the harvesting of grafts, during revascularization of the anterior and posterior/lateral wall, after protamine infusion, and after sternal fixation. In total, 145 sets of measurements were evaluated using Bland-Altman with % error calculation, correlation, concordance, and polar plot analyses. The percentage error (bias, limits of agreement) was 12.6 % (-0.12, -0.64 to 0.41 L/min), 26.7 % (-0.38, -1.50 to 0.74 L/min), 29.3 % (-0.08, -1.32 to 1.15 L/min), and 33.8 % (-0.05, -1.47 to 1.37 L/min) for transpulmonary thermodilution, pulmonary artery continuous thermodilution, calibrated, and uncalibrated pulse contour analysis, respectively, compared with pulmonary artery bolus thermodilution. All pairs of measurements showed significant correlations (p < 0.001), whereas only transpulmonary thermodilution revealed trending ability (concordance rate of 95.1 %, angular bias of 1.33°, and radial limits of agreement of 28.71°) compared with pulmonary artery bolus thermodilution. Transpulmonary thermodilution using the VolumeView™ system provides reliable data on cardiac output measurement and tracking the changes thereof when compared with pulmonary artery bolus thermodilution in patients with preserved cardiac function during off-pump coronary artery bypass surgery. Trial registration NCT01713192 (ClinicalTrials.gov). [ABSTRACT FROM AUTHOR]

In patients with acute circulatory failure, the decision to give fluids or not should not be taken lightly. The risk of overzealous fluid administration has been clearly established. Moreover, volume expansion does not always increase cardiac output as one expects. Thus, after the very initial phase and/or if fluid losses are not obvious, predicting fluid responsiveness should be the first step of fluid strategy. For this purpose, the central venous pressure as well as other 'static' markers of preload has been used for decades, but they are not reliable. Robust evidence suggests that this traditional use should be abandoned. Over the last 15 years, a number of dynamic tests have been developed. These tests are based on the principle of inducing short-term changes in cardiac preload, using heart-lung interactions, the passive leg raise or by the infusion of small volumes of fluid, and to observe the resulting effect on cardiac output. Pulse pressure and stroke volume variations were first developed, but they are reliable only under strict conditions. The variations in vena caval diameters share many limitations of pulse pressure variations. The passive leg-raising test is now supported by solid evidence and is more frequently used. More recently, the end-expiratory occlusion test has been described, which is easily performed in ventilated patients. Unlike the traditional fluid challenge, these dynamic tests do not lead to fluid overload. The dynamic tests are complementary, and clinicians should choose between them based on the status of the patient and the cardiac output monitoring technique. Several methods and tests are currently available to identify preload responsiveness. All have some limitations, but they are frequently complementary. Along with elements indicating the risk of fluid administration, they should help clinicians to take the decision to administer fluids or not in a reasoned way. [ABSTRACT FROM AUTHOR]

Haemodynamic goal-directed therapies (GDT) may improve outcome following elective major surgery. So far, few data exist regarding haemodynamic optimization during emergency surgery. In this randomized, controlled trial, 50 surgical patients with hypovolemic or septic conditions were enrolled and we compared two algorithms of GDTs based either on conventional parameters and pressure pulse variation (control group) or on cardiac index, global end-diastolic volume index and stroke volume variation as derived from the PiCCO monitoring system (optimized group). Postoperative outcome was estimated by a composite index including major complications and by the Sequential Organ Failure Assessment (SOFA) Score within the first 3 days after surgery (POD1, POD2 and POD3). Data from 43 patients were analyzed (control group, N = 23; optimized group, N = 20). Similar amounts of fluid were given in the two groups. Intraoperatively, dobutamine was given in 45 % optimized patients but in no control patients. Major complications occurred more frequently in the optimized group [19 (95 %) versus 10 (40 %) in the control group, P < 0.001]. Likewise, SOFA scores were higher in the optimized group on POD1 (10.2 ± 2.5 versus 6.6 ± 2.2 in the control group, P = 0.001), POD2 (8.4 ± 2.6 vs 5.0 ± 2.4 in the control group, P = 0.002) and POD 3 (5.2 ± 3.6 and 2.2 ± 1.3 in the control group, P = 0.01). There was no significant difference in hospital mortality (13 % in the control group and 25 % in the optimized group). Haemodynamic optimization based on volumetric and flow PiCCO-derived parameters was associated with a less favorable postoperative outcome compared with a conventional GDT protocol during emergency surgery. [ABSTRACT FROM AUTHOR]

The aim of this study was to compare the accuracy of the CeVOX monitor measuring continuous central venous saturation (ScvO2) with laboratory blood gas oximetry under clinical circumstances. Prospective, multicentre, observational study. Five adult general intensive care units. Fifty-three critically ill patients. The fibre-optic probe was inserted into an ordinary central venous catheter's distal lumen. Blood samples were taken from this line via a Y-adapter every 8 h and ScvO2 was measured with a laboratory co-oximeter. Patients were observed for a maximum of 5 days. Results were compared using linear regression and the Bland and Altman plots. The 526 matched pairs of ScvO2 showed a significant correlation between the two methods ( r = 0.79, p< 0.001). Bland–Altman plots showed an overall mean bias of –0.3% and moderate agreement (lower and upper levels of agreement: –13.2% and 12.5%). Correlation for the first time point, and for differences between the first two time points for each method revealed good correlation: ( n = 53): r = 0.79, p< 0.001; ( n = 50): r = 0.58, p< 0.001, respectively. These results in a heterogeneous group of critically ill patients show that continuous ScvO2 monitoring by the CeVOX technology yielded results comparable with those obtained by laboratory co-oximetry and therefore can be relied on in everyday clinical practice. [ABSTRACT FROM AUTHOR]

Comparison of the bias and the limits of agreement (LOA; 2 SD) of the central venous saturation (ScvO2) before, during and after coronary artery bypass graft surgery with a simultaneous measurement of the mixed venous saturation (SvO2). Prospective controlled study in a university hospital department of anaesthesiology. 60 patients with coronary artery bypass surgery, 300 paired measurements of SvO2 and ScvO2. ScvO2 and SvO2 were analysed after induction of anaesthesia 15 min after cardiopulmonary bypass and 1, 6 and 18 h after admission to the intensive care unit. Regression analysis for the pooled measurements of ScvO2 and SvO2 showed a correlation R 2 = 0.52. After induction of anaesthesia 15 min after weaning from cardiopulmonary bypass and 6 h after admission to the intensive care unit the correlation coefficient was R 2 = 0.46, on admission to the intensive care unit it was R 2 = 0.42, and at 18 h it was R 2 = 0.38. Bland–Altman analysis for the measurements of ScvO2 and SvO2 showed a mean bias and LOA of 0.3% and −11.9 to +12.4%. In patients with a low ScvO2 there was a trend to overestimate the SvO2 by using the ScvO2. The only factor that influenced the ΔSvO2 − ScvO2 was the oxygen extraction rate ( R 2 = 0.16). In patients with ScvO2 below 70% this association was more pronounced ( R 2 = 0.60). Our findings demonstrate that oxygen extraction rate is the major factor in the difference between SvO2 and ScvO2. Under certain circumstances ScvO2 differed substantially from SvO2. Therefore in selected patients both parameters should be monitored to exclude general or focal hypoperfusion. [ABSTRACT FROM AUTHOR]

Objective: To compare measurement of cardiac output (CO) by means of the FloTrac CO monitor with the pulmonary artery catheter (PAC).Design: Prospective observational study.Setting: Intensive care unit of a tertiary hospital.Patients: Six post-operative cardiac surgery patients with existing arterial cannulas and PACs.Interventions: Attachment of the FloTrac CO monitor and transducer to an existing arterial cannula. Simultaneous measurements of CO, indexed to body surface area (cardiac index, CI) by the FloTrac CO monitor and by either a bolus thermodilution or continuous CO PAC. Statistical analysis of observations.Measurements and Results: We performed CO measurements in six patients every 1-4 h after cardiac surgery. Comparison of all measurements showed a limited correlation for CI with the two devices (r (2)=0.1218, bias=0.21, 95% limits of agreement -0.81, 1.23). CI measurements obtained with the intermittent bolus PAC had better correlation with the FloTrac CI values (r (2) = 0.2693, bias=-0.0057, 95% limits of agreement -1.2042, 1.1929) than did those obtained with the continuous CO PAC (r (2)=0.0557, bias=0.2436, 95% limits of agreement -0.7350, 1.2222). When analysed according to heart rhythm, CI values measured during atrial pacing showed the best correlation (r (2)=0.377, bias=-0.0244, 95% limits of agreement -0.5226, 0.5714).Conclusions: CO measurements obtained using the FloTrac CO monitor show a limited correlation with those acquired using the PAC, relatively wide limits of agreement but no clear bias. Further evaluation is required before this device can be recommended for use in the clinical setting. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the clinical usefulness of near-infrared spatially resolved spectroscopic quantitative assessment of liver tissue oxygenation for simple, non-invasive estimation of global tissue oxygenation in critically ill neonates and children. Design: Prospective observational clinical study. Setting: A tertiary multidisciplinary neonatal and paediatric intensive care unit (23 beds). Patients: One hundred neonates and children consecutively admitted to the paediatric intensive care unit. Measurements and results: Near-infrared spectroscopic single-point assessment of liver tissue oxygenation index (TOILiver) was compared with global tissue oxygenation as measured by central venous oxygen saturation (SvO2) and derived haemodynamic parameters. Data were compared using linear and multiple regression analysis. Overall correlation between TOILiver and SvO2 was good (r=0.72, p<0.0001). Multivariable regression revealed that SvO2 alone explained 51% of the observed variance of TOILiver. However, our data demonstrated large inter-individual differences between SvO2 and TOILiver values. Conclusion: Near-infrared spatially resolved spectroscopic quantitative measurement of liver tissue oxygenation correlates well with SvO2 in critically ill neonates and children. Large inter-individual SvO2 to TOILiver differences may prevent its use for non-invasive single-point estimation of global tissue oxygenation. Further clinical studies are required to validate the method with other regional and global haemodynamic parameters and to evaluate its clinical use for continuous non-invasive haemodynamic monitoring. [ABSTRACT FROM AUTHOR]

Objectives: To assess the feasibility of constructing left ventricular response curves non-invasively during the fluid resuscitation of critically ill patients in the emergency department (ED) using a portable suprasternal Doppler ultrasound (PSSDU) device.Design: Prospective case series.Setting: Emergency department, Catholic University of Leuven, Belgium.Patients: Shocked patients in the ED were diagnosed by predefined criteria. Only those thought to require standardised intravenous colloid challenges were observed i. e., sequential boluses of 3.5 ml/kg/10 min titrated against changes in stroke distance (Doppler surrogate for left ventricular stroke volume).Results: A total of 50 shocked patients were studied. Stroke distance was measurable in 45 patients. 35 patients were fluid responders in terms of stroke distance. Group mean stroke distance increased during resuscitation (8.6 +/- 4.1 cm to 19.5 +/- 4.6 cm, P < 0.001) and then reached a plateau value (19.6 +/- 4.6 cm, P = 0.488). No response to fluid was seen in nine patients of which eight had severe sepsis. Alternative therapeutic approaches increased stroke distance for all of these patients. Evidence for right ventricular dysfunction was found as a cause for fluid non-response in the majority of patients with sepsis.Conclusions: Previous experimental work has shown that changes in central blood flow can be derived using the PSSDU device. This clinical feasibility study suggests that the PSSDU can help tailor haemodynamic therapy for an individual patient and give an early indication of treatment failure in the ED. [ABSTRACT FROM AUTHOR]

The application of Doppler-tipped guide wires to measure blood flow velocity in coronary and peripheral arteries has been described previously as a valuable means of functional assessment in interventional cardiological procedures. In animal studies intravascular Doppler has been used in the cerebrovascular system, and this appears to be an important field of application for this new technique. We used intravascular haemodynamic monitoring by the Doppler guide wire during neuroendovascular procedures in patients with different cerebrovascular diseases and evaluated the clinical feasibility of the method. We found it a safe technique which complements morphological angiographic information with valuable functional data. Further studies may be expected to demonstrate the relation of flow parameters to clinical outcome. [ABSTRACT FROM AUTHOR]

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Background: Femoral dP/dtmax (maximum rate of the arterial pressure increase during systole) measured by pulse contour analysis has been proposed as a surrogate of left ventricular (LV) dP/dtmax and as an estimator of LV systolic function. However, femoral dP/dtmax may be influenced by LV loading conditions. In this study, we evaluated the impact of variations of LV systolic function, preload and afterload on femoral dP/dtmax in critically ill patients with cardiovascular failure to ascertain its reliability as a marker of LV systolic function. Results: We performed a prospective observational study to evaluate changes in femoral dP/dtmax, thermodilution-derived variables (PiCCO2—Pulsion Medical Systems, Feldkirchen, Germany) and LV ejection fraction (LVEF) measured by transthoracic echocardiography during variations in dobutamine and norepinephrine doses and during volume expansion (VE) and passive leg raising (PLR). Correlations with arterial pulse and systolic pressure, effective arterial elastance, total arterial compliance and LVEF were also evaluated. In absolute values, femoral dP/dtmax deviated from baseline by 21% (201 ± 297 mmHg/s; p = 0.013) following variations in dobutamine dose (n = 17) and by 15% (177 ± 135 mmHg/s; p < 0.001) following norepinephrine dose changes (n = 29). Femoral dP/dtmax remained unchanged after VE and PLR (n = 24). Changes in femoral dP/dtmax were strongly correlated with changes in pulse pressure and systolic arterial pressure during dobutamine dose changes (R = 0.942 and 0.897, respectively), norepinephrine changes (R = 0.977 and 0.941, respectively) and VE or PLR (R = 0.924 and 0.897, respectively) (p < 0.05 in all cases). Changes in femoral dP/dtmax were correlated with changes in LVEF (R = 0.527) during dobutamine dose variations but also with effective arterial elastance and total arterial compliance in the norepinephrine group (R = 0.638 and R = − 0.689) (p < 0.05 in all cases). Conclusions: Pulse contour analysis-derived femoral dP/dtmax was not only influenced by LV systolic function but also and prominently by LV afterload and arterial waveform characteristics in patients with acute cardiovascular failure. These results suggest that femoral dP/dtmax calculated by pulse contour analysis is an unreliable estimate of LV systolic function during changes in LV afterload and arterial load by norepinephrine and directly linked to arterial waveform determinants. [ABSTRACT FROM AUTHOR]

Background: Femoral dP/dtmax (maximum rate of the arterial pressure increase during systole) measured by pulse contour analysis has been proposed as a surrogate of left ventricular (LV) dP/dtmax and as an estimator of LV systolic function. However, femoral dP/dtmax may be influenced by LV loading conditions. In this study, we evaluated the impact of variations of LV systolic function, preload and afterload on femoral dP/dtmax in critically ill patients with cardiovascular failure to ascertain its reliability as a marker of LV systolic function. Results: We performed a prospective observational study to evaluate changes in femoral dP/dtmax, thermodilution-derived variables (PiCCO2—Pulsion Medical Systems, Feldkirchen, Germany) and LV ejection fraction (LVEF) measured by transthoracic echocardiography during variations in dobutamine and norepinephrine doses and during volume expansion (VE) and passive leg raising (PLR). Correlations with arterial pulse and systolic pressure, effective arterial elastance, total arterial compliance and LVEF were also evaluated. In absolute values, femoral dP/dtmax deviated from baseline by 21% (201 ± 297 mmHg/s; p = 0.013) following variations in dobutamine dose (n = 17) and by 15% (177 ± 135 mmHg/s; p < 0.001) following norepinephrine dose changes (n = 29). Femoral dP/dtmax remained unchanged after VE and PLR (n = 24). Changes in femoral dP/dtmax were strongly correlated with changes in pulse pressure and systolic arterial pressure during dobutamine dose changes (R = 0.942 and 0.897, respectively), norepinephrine changes (R = 0.977 and 0.941, respectively) and VE or PLR (R = 0.924 and 0.897, respectively) (p < 0.05 in all cases). Changes in femoral dP/dtmax were correlated with changes in LVEF (R = 0.527) during dobutamine dose variations but also with effective arterial elastance and total arterial compliance in the norepinephrine group (R = 0.638 and R = − 0.689) (p < 0.05 in all cases). Conclusions: Pulse contour analysis-derived femoral dP/dtmax was not only influenced by LV systolic function but also and prominently by LV afterload and arterial waveform characteristics in patients with acute cardiovascular failure. These results suggest that femoral dP/dtmax calculated by pulse contour analysis is an unreliable estimate of LV systolic function during changes in LV afterload and arterial load by norepinephrine and directly linked to arterial waveform determinants. [ABSTRACT FROM AUTHOR]