Continuous Cardiac Output Monitoring Research Articles

The Changes in Pulse Pressure Variation or Stroke Volume Variation After a "Tidal Volume Challenge" Reliably Predict Fluid Responsiveness During Low Tidal Volume Ventilation.

Stroke volume variation and pulse pressure variation do not reliably predict fluid responsiveness during low tidal volume ventilation. We hypothesized that with transient increase in tidal volume from 6 to 8 mL/kg predicted body weight, that is, "tidal volume challenge," the changes in pulse pressure variation and stroke volume variation will predict fluid responsiveness. Prospective, single-arm study. Medical-surgical ICU in a university hospital. Adult patients with acute circulatory failure, having continuous cardiac output monitoring, and receiving controlled low tidal volume ventilation. The pulse pressure variation, stroke volume variation, and cardiac index were recorded at tidal volume 6 mL/kg predicted body weight and 1 minute after the "tidal volume challenge." The tidal volume was reduced back to 6 mL/kg predicted body weight, and a fluid bolus was given to identify fluid responders (increase in cardiac index > 15%). The end-expiratory occlusion test was performed at tidal volumes 6 and 8 mL/kg predicted body weight and after reducing tidal volume back to 6 mL/kg predicted body weight. Thirty measurements were obtained in 20 patients. The absolute change in pulse pressure variation and stroke volume variation after increasing tidal volume from 6 to 8 mL/kg predicted body weight predicted fluid responsiveness with areas under the receiver operating characteristic curves (with 95% CIs) being 0.99 (0.98-1.00) and 0.97 (0.92-1.00), respectively. The best cutoff values of the absolute change in pulse pressure variation and stroke volume variation after increasing tidal volume from 6 to 8 mL/kg predicted body weight were 3.5% and 2.5%, respectively. The pulse pressure variation, stroke volume variation, central venous pressure, and end-expiratory occlusion test obtained during tidal volume 6 mL/kg predicted body weight did not predict fluid responsiveness. The changes in pulse pressure variation or stroke volume variation obtained by transiently increasing tidal volume (tidal volume challenge) are superior to pulse pressure variation and stroke volume variation in predicting fluid responsiveness during low tidal volume ventilation.

Comparing the Rates of Dopamine Hemodynamic Effect Onset after Infusion through Peripheral Veins in Three Regions.

Background Dopamine is an inotropic agent that is often selected for continuous infusion. For hemodynamic stability, the rate of infusion is controlled in the range of 5-15 μg/kg/min. This study aimed to compare the time intervals from the administration of dopamine to the onset of its hemodynamic effects when dopamine was administered through three different peripheral veins (the cephalic vein [CV], the great saphenous vein [GSV], and the external jugular vein [EJV]).Methods Patients in group 1, group 2, and group 3 received dopamine infusions in the CV, GSV, and EJV, respectively. A noninvasive continuous cardiac output monitor (NICCOMO™, Medis, Ilmenau, Germany) was used to assess cardiac output (CO) and systemic vascular resistance (SVR). Six minutes after intubation, baseline heart rate (HR), systolic blood pressure (BP), diastolic BP, mean arterial pressure (MAP), CO, and SVR values were recorded and dopamine infusion was initiated at a dose of 10 μg/kg/min. Hemodynamic changes at 0, 4, 8, 12, and 15 minutes postinfusion were recorded.Results No statistically significant differences were observed among the three groups with respect to the rate of hemodynamic change. In all groups, systolic BP, diastolic BP, MAP, and SVR tended to increase after decreasing for the first 4 minutes; in contrast, HR and CO decreased until 8 minutes, after which they tended to reach a plateau.Conclusions For patients under general anesthesia receiving dopamine at 10 μg/kg/min, there were no clinical differences in the effect of dopamine administered through three different peripheral veins.

Effective Illustration of Decommissioning of Left Ventricular Assist Device after Bridge-to-Recovery by Hybrid Minimally-Invasive Tactic: Anesthesia Substances

We report successful decommissioning of HeartWare left ventricular assist device (LVAD) (HVAD, HeartWare Inc., Framingham, MA) leaving the pump in situ by hybrid percutaneous approach. In this case, the indication for mechanical assist device separation was myocardial recovery, which occurred following 19 months of LVAD support. Anaesthetic goals include maintenance of sinus rhythm, avoidance of myocardial depression and increase in systemic vascular resistance (SVR), with optimal blood pressure control, normothermia, and judicious fluid management. Intraoperative assessment of suitability to wean using transesophageal echocardiography (TEE) and continuous cardiac output monitoring with pulmonary artery catheter must be expedient as no anticoagulation is given. This case report demonstrates the feasibility of separating a patient from a LVAD without the need for a major re-operative intervention.

Perioperative management of obstetrical surgeries in women having coexisting cardiovascular disease: our experience

Background and aim: Coexisting cardiovascular disease in pregnancy is associated with high maternal morbidity and mortality. These patients pose a great challenge to both anesthesiologist and obstetrician. Present study was aimed at reviewing the perioperative management and outcome of obstetrical surgeries in women who had coexisting cardiovascular disease in a tertiary care teaching institute. Materials and Methods: Departmental database of all pregnant patients with coexisting cardiovascular diseases who underwent obstetrical surgeries during January 2011 to August 2016 were reviewed. Patients functional status, obstetrical history, stage of labor, type of anaesthesia, monitoring, hemodynamics, post operative care and baby outcome were noted. Data are expressed in absolute number and percentage scale and INSTAT software was used for measuring central tendencies and dispersion. Results: A total of 22 women (mean + Standard deviation: SD age 26.18 + 4.78 years) were found eligible and included for analysis. 21(95.45%) patients underwent cesarean section and one medical termination of pregnancy. 68.18% cases were done under subarachnoid block. Most of the patient needed post operative high dependant unit care, one patient developed mild pulmonary edema and no maternal and fetal deaths were noted. All the babies were born with APGAR > 7 at 1 min. No patient was managed using pulmonary artery catheter or continuous cardiac output monitoring. Conclusion: Pregnant patients with coexisting cardiovascular disease need multidisciplinary approach, timely delivery and intensive therapy in perioperative period. They can be safely delivered under subarachnoid blocks. Pulmonary artery catheterization is probably not an essential for hemodynamics management of such patients in perioperative management.

Fluid responsiveness prediction using Vigileo FloTrac measured cardiac output changes during passive leg raise test.

BackgroundPassive leg raising (PLR) is a so called self-volume challenge used to test for fluid responsiveness. Changes in cardiac output (CO) or stroke volume (SV) measured during PLR are used to predict the need for subsequent fluid loading. This requires a device that can measure CO changes rapidly. The Vigileo™ monitor, using third-generation software, allows continuous CO monitoring. The aim of this study was to compare changes in CO (measured with the Vigileo device) during a PLR manoeuvre to calculate the accuracy for predicting fluid responsiveness.MethodsThis is a prospective study in a 20-bedded mixed general critical care unit in a large non-university regional referral hospital. Fluid responders were defined as having an increase in CO of greater than 15 % following a fluid challenge. Patients meeting the criteria for circulatory shock with a Vigileo™ monitor (Vigileo™; FloTrac; Edwards™; Lifesciences, Irvine, CA, USA) already in situ, and assessed as requiring volume expansion by the clinical team based on clinical criteria, were included. All patients underwent a PLR manoeuvre followed by a fluid challenge.ResultsData was collected and analysed on stroke volume variation (SVV) at baseline and CO and SVV changes during the PLR manoeuvre and following a subsequent fluid challenge in 33 patients. The majority had septic shock. Patient characteristics, baseline haemodynamic variables and baseline vasoactive infusion requirements were similar between fluid responders (10 patients) and non-responders (23 patients). Peak increase in CO occurred within 120 s during the PLR in all cases. Using an optimal cut point of 9 % increase in CO during the PLR produced an area under the receiver operating characteristic curve of 0.85 (95 % CI 0.63 to 1.00) with a sensitivity of 80 % (95 % CI 44 to 96 %) and a specificity of 91 % (95 % CI 70 to 98 %).ConclusionsCO changes measured by the Vigileo™ monitor using third-generation software during a PLR test predict fluid responsiveness in mixed medical and surgical patients with vasopressor-dependent circulatory shock.Electronic supplementary materialThe online version of this article (doi:10.1186/s40560-016-0188-6) contains supplementary material, which is available to authorized users.

383. Clinico-Pathological Correlation in the Earliest Stages of Muscular Dystrophy Suggests Sensitive Physiological Parameters as Novel Primary Endpoints for Systemic Gene Therapy

The clinical progression of Duchenne Muscular Dystrophy (DMD) begins with locomotive symptoms in childhood but eventually includes symptoms of severe cardiorespiratory failure. Our studies in mdx mice and GRMD dogs have reavealed surprisingly large early deficits in physiological reserve, attributable to the deficiency of dystrophin. In young GRMD dogs, the findings of diaphragmatic fibrosis and myofiber shortening correlated strongly with non-invasively measured abnormalities in respiratory muscle recruitment. In juvenile GRMD dogs without clinical signs of heart failure, detailed studies of cardiac mechanics revealed profoundly abnormal Frank-Starling and inotropic responses. Thus, submaximal exercise loading has the capactiy to reveal very early, otherwise subclinical deficits in physiological reserve. We have utilized several non-invasive systems to measure integrative cardiopulmonary mechanics in animals trained to undertake submaximal volitional exercise. Our findings demonstrate the possibility of continuous non-invasive monitoring of cardiac output, stroke volume, systemic vascular resistance, and several ventilatory parameters in young dogs and children during treadmill exercise, as well as upright and recumbent bicycling at work outputs appropriate for low risk serial testing in the earliest stages of DMD. As the field contemplates primary endpoints for use in trials of systemic gene therapy, these metrics hold promise as the most sensitive measurements of the earliest functional deficits in organ systems eventually responsible for the lethality of DMD.

Age-related incidence of desaturation events and the cardiac responses on stroke index, cardiac index, and heart rate measured by continuous bioimpedance noninvasive cardiac output monitoring in infants and children undergoing general anesthesia

Study objectiveTo assess the effects of desaturation on stroke index (SI), cardiac index (CI), and heart rate (HR) using the ICON continuous noninvasive cardiac output monitor in children undergoing general anesthesia. DesignRetrospective analysis of a prospectively collected data set. SettingPediatric operating rooms in a tertiary academic medical center. PatientsChildren younger than 20 years who experienced desaturation while undergoing general anesthesia. InterventionAll records were retrospectively searched for desaturation events defined as a recorded Spo2 ≤ 90%. We compared the data from the prior 4 minutes (baseline) with mild, moderate, and severe levels of desaturation. MeasurementsThe relationship between Spo2 and percent change in SI, CI, and HR from baseline was assessed using a generalized linear model with repeated measures and the least-squares method. Main resultsData from 446 patients were reviewed; 38 events were eligible for analysis after exclusions. There were significant decreases in SI at all saturation ranges below 95%: −6.5% (P < .001) for 85%-95%, −8.9% (P = .002) for 71%-84%, and −11% (P < .001) for ≤70%. Based on the result from the regression, Spo2 was associated with change in SI with borderline significance (P = .053) but not that of HR and CI. There was a strong relationship to desaturation events with young age (P < .001), particularly infants younger than 6 months. ConclusionEvents associated with desaturation in children under general anesthesia were significantly associated with decreased SI with a greater effect with lower saturation nadirs. It is unclear if other concurrent events could have also contributed to adverse hemodynamic responses during desaturation. In most children, a compensatory increase in HR generally offsets concurrent decreases in CI. It would appear that bradycardia is a late manifestation of hypoxemia.

A retrospective analysis of liver resection performed without central venous pressure monitoring

BackgroundStudies have suggested that blood loss can be reduced during liver resection by monitoring and maintaining low central venous pressure (CVP) through fluid restriction or other means, but such a strategy carries risks to the patient including those inherent to central venous catheterization. We sought to characterize fluid management and blood loss during liver resections done without CVP monitoring. MethodsRetrospective data were extracted from electronic anesthesia records for 993 liver resections. For 135 resections, between 2011 through 2013, where a documentation template was used that recorded fluid administration prior to hepatic inflow occlusion, multivariate analysis was performed to test for an association between pre-clamp fluid volumes administered and blood loss and other adverse outcomes. ResultsThe median estimated blood loss was 300 mL and overall rate of transfusion was 8.6%. There was no statistically significant association between crystalloid volume administered prior to inflow clamping (median 900 mL) and blood loss, mortality or length of stay in the subset of patients with supplemental fluid data. ConclusionLiver resection can be performed safely without either CVP monitoring or non-invasive continuous cardiac output monitoring. Additionally, there was no disadvantage to a practical approach to fluid administration prior to inflow clamping during liver resections in the absence of CVP monitoring with regard to blood loss or short-term outcomes.

Experts' opinion on management of hemodynamics in ARDS patients: focus on the effects of mechanical ventilation.

Acute respiratory distress syndrome (ARDS) is frequently associated with hemodynamic instability which appears as the main factor associated with mortality. Shock is driven by pulmonary hypertension, deleterious effects of mechanical ventilation (MV) on right ventricular (RV) function, and associated-sepsis. Hemodynamic effects of ventilation are due to changes in pleural pressure (Ppl) and changes in transpulmonary pressure (TP). TP affects RV afterload, whereas changes in Ppl affect venous return. Tidal forces and positive end-expiratory pressure (PEEP) increase pulmonary vascular resistance (PVR) in direct proportion to their effects on mean airway pressure (mPaw). The acutely injured lung has a reduced capacity to accommodate flowing blood and increases of blood flow accentuate fluid filtration. The dynamics of vascular pressure may contribute to ventilator-induced injury (VILI). In order to optimize perfusion, improve gas exchange, and minimize VILI risk, monitoring hemodynamics is important. During passive ventilation pulse pressure variations are a predictor of fluid responsiveness when conditions to ensure its validity are observed, but may also reflect afterload effects of MV. Central venous pressure can be helpful to monitor the response of RV function to treatment. Echocardiography is suitable to visualize the RV and to detect acute cor pulmonale (ACP), which occurs in 20-25% of cases. Inserting a pulmonary artery catheter may be useful to measure/calculate pulmonary artery pressure, pulmonary and systemic vascular resistance, and cardiac output. These last two indexes may be misleading, however, in cases of West zones 2 or 1 and tricuspid regurgitation associated with RV dilatation. Transpulmonary thermodilution may be useful to evaluate extravascular lung water and the pulmonary vascular permeability index. To ensure adequate intravascular volume is the first goal of hemodynamic support in patients with shock. The benefit and risk balance of fluid expansion has to be carefully evaluated since it may improve systemic perfusion but also may decrease ventilator-free days, increase pulmonary edema, and promote RV failure. ACP can be prevented or treated by applying RV protective MV (low driving pressure, limited hypercapnia, PEEP adapted to lung recruitability) and by prone positioning. In cases of shock that do not respond to intravascular fluid administration, norepinephrine infusion and vasodilators inhalation may improve RV function. Extracorporeal membrane oxygenation (ECMO) has the potential to be the cause of, as well as a remedy for, hemodynamic problems. Continuous thermodilution-based and pulse contour analysis-based cardiac output monitoring are not recommended in patients treated with ECMO, since the results are frequently inaccurate. Extracorporeal CO2 removal, which could have the capability to reduce hypercapnia/acidosis-induced ACP, cannot currently be recommended because of the lack of sufficient data.

Pulse-induced Continuous Cardiac Output Monitor versus Trans-esophageal Doppler Monitor for Optimization of Fluid Management in Patients Undergoing Major Abdominal Surgery. A Comparative Study

Pulse-induced Continuous Cardiac Output Monitor versus Trans-esophageal Doppler Monitor for Optimization of Fluid Management in Patients Undergoing Major Abdominal Surgery. A Comparative Study

Perioperative Management of Obstetrical Surgeries in Women Having Coexisting Cardiovascular Disease: Our Experience

Background and aim: Coexisting cardiovascular disease in pregnancy is associated with high maternal morbidity and mortality. These patients pose a great challenge to both anesthesiologist and obstetrician. The present study was aimed at reviewing the perioperative management and outcome of obstetrical surgeries in women who had coexisting cardiovascular disease in a tertiary care teaching institute. Materials and Methods: Departmental database of all pregnant patients with coexisting cardiovascular diseases who underwent obstetrical surgeries from January 2011 to August 2016 were reviewed. Patients functional status, obstetrical history, stage of labor, type of anaesthesia, monitoring, hemodynamics, post-operative care, and baby outcome were noted. Data are expressed in absolute number and percentage scale and INSTAT software was used for measuring central tendencies and dispersion. Results: A total of 22 women (mean + Standard deviation: SD age 26.18 + 4.78 years) were found eligible and included for analysis. 21(95.45%) patients underwent cesarean section and one medical termination of pregnancy. 68.18% of cases were done under subarachnoid block. Most of the patient needed postoperative high dependant unit care, one patient developed mild pulmonary edema and no maternal and fetal deaths were noted. All the babies were born with APGAR > 7 at 1 min. No patient was managed using a pulmonary artery catheter or continuous cardiac output monitoring. Conclusion: Pregnant patients with the coexisting cardiovascular disease need multidisciplinary approach, timely delivery and intensive therapy in the perioperative period. They can be safely delivered under subarachnoid blocks. Pulmonary artery catheterization is probably not essential for hemodynamics management of such patients in perioperative management.

Joint effects of hydroxyethyl starch and furosemide on acute lung injury induced by paraquat in swine

Objective To discuss the jointly therapeutic effects of 6% hydroxyethyl starch 130/ 0.4 (voluven) and furosemide on acute lung injury induced by paraquat (PQ) in swine. Methods The ALI/ARDS models were established with 20% PQ (20 mL) intraperitoneal injection in 18 healthy female piglets and randomly divided into three groups: voluven group (A) , furosemide group (B) and voluven +furosemide group (C) (n=6 in each group). The heart rate (HR) , mean arterial pressure (MAP) , extravascular lung water index (ELWI) , pulmonary vascular permeability index (PVPI) , partial pressure of carbon dioxide (PaCO2) and oxygenation index (PaO2/FiO2) among the three groups were carefully measured by PICCO (pulse indicator continuous cardiac output) before modeling (baseline) , just after modeling (t0) , and 2 h (t2) , 4 h (t4) , 6 h (t6) and 8 h (t8) after trearment. Needle biopsies of lung tissue were made before modeling and at t0 and t8 and prepared for microscopy observation after Hematoxylin- eosin staining method (HE staning). Repeated measurement data were compared among repeated measures by the ANOVA and the difference between groups was compared by one-wey ANOVA. Results (1) The HR and MAP of all animals increased obviously while the oxygenation index declined significantly at modeling just made (t0) compared to those before modeling (all P 0.05). (2) The ELWI and PVPI of all animals increased obviously at modeling just made (t0) compared to those before modeling (all P <0.05). The ELWI and PVPI were decreased after treatment. And at the same time, the ELWI and PVPI of A and B groups were significantly lower than those of C group after treatment (all P <0.05). (3) The alveolar tissue showed obviously injured changes at modeling just made (t0). The injury was relieved 8h after trearment, which was most markedly in group C. Conclusions With the combination of 6% hydroxyethyl starch 130/ 0.4 and furosemide administered, the acute lung injury induced by paraquat poisoning can be effectively relieved, promoting gas exchange, and improve oxygenation. Key words: Paraquat; Acute lung injury; 6% hydroxyethyl starch 130/ 0.4; Furosemide; Pulse indicates continuous cardiac output monitoring; Extravascular lung water index; Pulmonary vascular permeability index; Oxygenation index

Effects of mild hypothemia on hemodynamics of systemic and renal of dog with septic shock

To explore the effects of mild hypothemia on hemodynamics of systemic and renal of dog with septic shock. 40 healthy dogs were randomly and evenly divided into the normal temperature non-infected group (NTNS), normal temperature infected group (NTS), hypothermia non-infected group (MHNS) and hypothermia infected group (MHS). NTS and MHS were pumped through the femoral vein of Escherichia coli (E.coli 1 × 10⁹ cfu/ml) by 0.5 ml·kg⁻¹·h⁻¹, producting septic shock model with high-power cycle. Combining with blood pump devices and low temperature thermostat bath, the MHNS and MHS implemented extracorporeal blood cooling method to maintain the blood in temperature (33 ± 1) °C. 0, 24, 48, 72 h point, tested specimens from femoral vein for renal function. In the 0-72 h. Pulse indicates the continuous cardiac output monitor (PiCCO) monitored systemic hemodynamics on each time point. In the 0-72 h, color Doppler ultrasound (CDFI) measured renal hemodynamic on each time point. There was an increase of SBP (P<0.05), SVR [(2 415 ± 651) dyn·s·cm⁻⁵ vs (1 613 ± 223) dyn·s·cm⁻⁵, P=0.01] and RI (P=0.04) in the MHS group comparing with the NTS group from 24 to 72 h. CO [(3.58 ± 0.44) L/min vs (4.18 ± 0.60) L/min, P=0.04], HR and PSV was decreased in the MHS group. BUN [(8.6 ± 1.6) mmol/L vs (21.2 ± 4.8) mmol/L, P<0.01] and Scr [(167.6 ± 31.2) µmol/L vs (383.8 ± 35.2) µmol/L, P<0.01] was decreased in MHS group comparing with the NTS group. There was a positively correlation between CO and PSV in the canine model of septic shock (P<0.01); and CO was negatively correlated with RI (P<0.01). In this canine model of septic shock, hypothermia can stable systemic and renal hemodynamics, and improve kidney function.

Is heart-rate complexity a surrogate measure of cardiac output before, during, and after hemorrhage in a conscious sheep model of multiple hemorrhages and resuscitation?

Despite its medical utility, continuous cardiac output (CO) monitoring remains a practical challenge on the battlefield and in the prehospital environment. Measuring a CO surrogate, perhaps heart-rate complexity (HRC), might be a viable solution when no direct monitoring of CO is available. Changes in HRC observed before and during hemorrhagic shock may be able to track the simultaneous changes in CO. The goal of this study was to test whether HRC is a surrogate measure of CO before, during, and after hemorrhage in a conscious sheep model of multiple hemorrhages and resuscitation. HRC was derived from 100-Hz electrocardiograms of 10 sheep records, 3 hours to 4 hours long, using the method of sample entropy. A real-time detection algorithm was used to detect the R-R interval sequences for HRC calculations. All records contained 100-Hz recordings of pulmonary arterial blood flow using Doppler transit time (criterion standard CO). Gold CO and estimated HRC values were analyzed using overlaid time-synchronized waveform plots as well as Bland-Altman, regression, and four-quadrant analysis. Baseline CO varied from 3.0 L/min to 5.4 L/min, while posthemorrhage CO varied from 1.0 L/min to 1.8 L/min. Importantly, overlaid plots demonstrated an overall high similarity between CO and HRC waveforms before and during hemorrhage, but not during resuscitation. When the electrocardiogram quality was high, the correlation between CO and HRC within the first 45 minutes was greater than 0.75 (p < 0.0001; maximum r, 0.972). Scatter plots also depicted high linearity before and during hemorrhage. Four-quadrant analysis showed that instantaneous changes between consecutive beat-to-beat HRC measurements followed CO measurements (100% concordance rate), while 5-minute time points yielded a 76.19% concordance rate. HRC has potential utility as a noninvasive tool for assessing the response of CO to life-threatening injuries such as hemorrhagic shock. However, further investigation and other animal models or human studies are needed.

The influence of continuous venovenous hemofiltration on parameter measurement by the transpulmonary thermodilution technique

To evaluate the influence of continuous venovenous hemofiltration (CVVH) on measurement of transpulmonary thermodilution parameters. A prospective observational study was conducted. Fifty-six patients who received CVVH and hemodynamic monitoring at the same time admitted to the Department of Critical Care Medicine of Tianjin Third Central Hospital from July 2012 to July 2014 were enrolled. In all the patients, the dialysis catheter was inserted through the femoral vein, and transpulmonary thermodilution measurements were performed by pulse indicator continuous cardiac output (PiCCO) monitoring technology at the same time. Mean arterial pressure (MAP), central blood temperature, cardiac index (CI), global end-diastolic volume index (GEDVI), intrathoracic blood volume index (ITBVI) and extravascular lung water index (EVLWI) were measured before CVVH, immediately after CVVH, and 30 minutes after CVVH, respectively. Results In the 56 patients, there were 36 males and 20 females, (66 ± 16) years of old, height of (172 ± 6) cm, body weight of (68 ± 10) kg. The acute physiology and chronic health evaluation II (APACHE II) scores was 26 ± 6. After CVVH, the central blood temperature was gradually decreased, and blood temperature at 30 minutes after CVVH was significantly lower than that before CVVH (degrees C : 37.17 ± 1.06 vs. 37.57 ± 1.26, P < 0.01). There were no significant changes in MAP and EVLWI before and after CVVH the MAP was (89 ±20), (86 ± 16), (90 ± 17) mmHg ( 1 mmHg = 0.133 kPa) at three time points respectively, and EVLWI was (9.4 ± 3.2, (9.3 ± 3.0), (9.4 ± 2.9) mL/kg, respectively. After CVVH, CI, GEDVI and ITBVI showed a gradual downward tendency. Compared with those before CVVH, the decline of CI, GEDVI, and ITBVI immediately after CVVH was not statistically significant [CI (mL x s (-1) x m(-2): 62.18 ± 24.34 vs 63.85 ± 21.84, GEDVI (mL/m2): 705 ± 103 vs 727 ± 100, ITBVI (mL/m2): 881 ± 129 vs 908 ± 125, all P > 0.05]. CI, GEDVI, ITBVI at 30 minutes after CVVH were significantly decreased [CI mL x s(-1) x m(-2)): 57.84 ± 20.50 vs 63.85 ± 21.84, GEDVI (mL/m2): 681 ± 106 vs. 727 ± 100, ITBVI (mL/m2): 851 ± 133 vs. 908 ± 125, all P < 0.05]. CVVH was associated with a decline of 6.01 mL x s(-1) x m(-2) at 30 minutes after CVVH [95% confidence interval (95% CI)) = -10.67 to -1.50, P = 0.011]. The declines of GEEDVI and ITBVI were observed with 46 mL/m2 (95% CI = -81 to - 11, P = 0.014), 57 mL/m2 (95% CI = -101 to -13, P = 0.014) respectively 30 minutes after CVVH. CVVH had no significant effect on the transpulmonary thermodilution measurement of CI, GEDVI, ITBVI and EVLWI. Thirty minutes after the start of CVVH, CI, GEDVI was decreased significantly, but had no effect on EVLWI.

Influence of tidal volume on pulse pressure variation and stroke volume variation during experimental intra-abdominal hypertension.

BackgroundPulse pressure variation (PPV) and stroke volume variation (SVV) are frequently used to assess fluid responsiveness in critically ill patients on mechanical ventilation (MV). There are many factors, in addition to preload that influence the magnitude of these cyclic variations. We sought to investigate the effect of tidal volume (VT) on PPV and SVV, and prediction of fluid responsiveness in a model of intra-abdominal hypertension (IAH).MethodsTwelve anesthetized and mechanically ventilated piglets on continuous pulse contour cardiac output monitoring. Hypovolemia was ruled out with 2 consecutive fluid boluses after instrumentation. IAH was induced by intraperitoneal instillation of colloid solution with a goal of reducing respiratory system compliance by 50 %. Subjects were classified as fluid responders if stroke volume increased >15 % after each fluid challenge. SVV and PPV were recorded with tidal volumes (VT) of 6, 12 and 18 ml/kg before IAH after IAH induction and after a fluid challenge during IAH.ResultsVT influenced PPV and SVV at baseline and during IAH, being significantly larger with higher VT. These differences were attenuated after fluid administration in both conditions. After IAH induction, there was a significant increase in SVV with the three-tested VT, but the magnitude of that change was larger with high VT: with 6 ml/kg from 3 % (3, 4) to 5 % (4, 6.25) (p = 0.05), with 12 ml/kg from 5 % (4, 6) to 11 % (8.75, 17) (p = 0.02) and 18 ml/kg from 5 % (4,7.5) to 15 % (8.75, 19.5) (p = 0.02). Similarly, PPV increased with all the tested VT after IAH induction, being this increase larger with high VT: with 6 ml/kg from 3 % (2, 4.25) to 6 % (4.75, 7) (p = 0.05), with 12 ml/kg from 5 % (4, 6) to 13.5 % (10.25, 15.5) (p = 0.02) and 18 ml/kg from 7 % (5.5, 8.5) to 24 % (13.5, 30.25) (p = 0.02). One third of subjects responded to fluid administration after IAH, but neither SVV nor PPV were able to identify the fluid responders with the tested VT.ConclusionIAH induction in non-hypovolemic subjects significantly increased SVV and PPV with the three tested VT, but the magnitude of that change was higher with larger VT. This observation reveals the dependence of functional hemodynamic markers on intrathoracic as well intra-abdominal pressures, in addition to volemic status. Also, PPV and SVV were unable to predict fluid responsiveness after IAH induction. Future studies should take into consideration these findings when exploring relationships between dynamic preload indicators and fluid responsiveness during IAH.Electronic supplementary materialThe online version of this article (doi:10.1186/s12871-015-0105-x) contains supplementary material, which is available to authorized users.

Prognostic value of extravascular lung water assessed with lung ultrasound score by chest sonography in patients with acute respiratory distress syndrome.

BackgroundThe prognostic value of extravascular lung water indices (EVLWI) has been widely investigated, which is determined by lung ultrasound B-lines. However, the clinical value of lung ultrasound B-lines for determining prognosis/intensive care unit (ICU) outcomes in patients with acute respiratory distress syndrome (ARDS) has been rarely reported.MethodsTwenty-one ARDS patients admitted to the ICU of Fu Xing Hospital underwent both lung ultrasonography and pulse index continuous cardiac output (PiCCO) monitoring on the first, second, and third days after diagnosis. The correlation between lung ultrasound score (LUS) and EVLWI measured by the PiCCO system was investigated. The prognostic clinical value of lung ultrasonography in ARDS patients was explored. Chest ultrasound was performed using the 12 regions method. The comprehensive score of lung ultrasound was determined according to the level of lung aeration.ResultsWith ICU mortality as the end point, 21 patients were divided into a survivor group (8 patients, 39.1 %) and a non-survivor group (13 patients, 61.9 %). Significant positive linear correlations were found between LUS and EVLWI, including predicted body weight (r2 = 0.906), sequential organ failure assessment score (r2 = 0.815), lung injury score (r2 = 0.361), and PaO2/FiO2 (r2 = 0.472). Significantly different LUSs were found between the non-survivor and survivor groups (F = 77.64, P <0.01) by repeated-measures analysis of variance. There were no significant differences between the two groups on different days. The areas under the receiver operating characteristic curves of LUS and EVLW measured by PiCCO were 0.846 (P < 0.01) and 0.918 (P < 0.01), respectively. The cut-off of LUS for prognosis prediction was 16.5.ConclusionsLung ultrasonography is a non-invasive, economic, simple, user-friendly, and radiation-free bedside method for predicting the prognosis of ARDS patients. Early measurement of LUS is a better prognostic indicator in patients with ARDS.

Central venous pressure in combination with visual left ventricular ejection fraction as an indicator of fluid responsiveness in patients with septic shock

Objective To investigate the value of central venous pressure(CVP) combined with visual left ventricular ejection fraction(LVEF)as an indicator of fluid responsiveness in patients with septic shock. Methods A retrospective analysis of 83 patients with septic shock receiving fluid challenge was conducted. The hemodynamic changes were evaluated with the pulse indicator continuous cardiac output (PiCCO) monitor, and all the patients were divided into two groups: the responded group(△CI% ≥ 15%)and the unresponded group(△CI < 15%), according to the change in CI(△CI%). Those patients were divided into several subgroups, including low CVP group(CVP < 8 mmHg) and high CVP group(CVP ≥ 8 mmHg), low LVEF group(LVEF < 50%) and high LVEF group(LVEF ≥ 50%), according to the initial value of CVP and LVEF. The changes in hemodynamic variables were compared before and after fluid challenge in each subgroup. The ability of CVP and visual LVEF was evaluated to predict fluid responsiveness with receiver operating characteristic curves. Results Fifty three (63.9%)patients responded to the fluid challenge, and lower CVP and higher LVEF patients were more frequency in responded group. The threshold value of 8 mmHg CVP for prediction of fluid responsiveness revealed the area under the curve (AUC) of 0.646(P=0.219), and 50% visual LVEF revealed AUC of 0.729(P=0.023). CVP in combination with visual LVEF for prediction of fluid responsiveness showed an AUC of 0.817 (P=0.001) with a sensitivity of 76.3% and a specificity of 88.2%. Conclusions Visual LVEF alone and combined with CVP can be used as an indicator of fluid responsiveness in patients with septic shock. Key words: Central venous pressure; Heart ventricles/US; Ventricular function, left; Stroke volume; Shock/DI/PP; Hemodynamics

Comparison of cardiac output measured by oesophageal Doppler ultrasonography or pulse pressure contour wave analysis

Maintaining adequate organ perfusion during high-risk surgery requires continuous monitoring of cardiac output to optimise haemodynamics. Oesophageal Doppler Cardiac Output monitoring (DCO) is commonly used in this context, but has some limitations. Recently, the cardiac output estimated by pulse pressure analysis- (PPCO) was developed. This study evaluated the agreement of cardiac output variations estimated with 9 non-commercial algorithms of PPCO compared with those obtained with DCO. High-risk patients undergoing neurosurgery were monitored with invasive blood pressure and DCO. For each patient, 9 PPCO algorithms and DCO were recorded before and at the peak effect for every haemodynamic challenge. Sixty-two subjects were enrolled; 284 events were recorded, including 134 volume expansions and 150 vasopressor boluses. Among the 9 algorithms tested, the Liljestrand-Zander model led to the smallest bias (0.03 litre min(-1) [-1.31, +1.38] (0.21 litre min(-1) [-1.13; 1.54] after volume expansion and -0.13 litre min(-1) [-1.41, 1.15] after vasopressor use). The corresponding percentage of the concordance was 91% (86% after volume expansion and 94% after vasopressor use). The other algorithms, especially those using the Winkessel concept and the area under the pressure wave, were profoundly affected by the vasopressor. Among the 9 PPCO algorithms examined, the Liljestrand-Zander model demonstrated the least bias and best limits of agreement, especially after vasopressor use. Using this particular algorithm in association with DCO calibration could represent a valuable option for continuous cardiac output monitoring of high risk patients. Comité d'éthique de la Société de Réanimation de Langue Française No. 11-356.

The effect of anticoagulant therapy on coagulation and inflammation markers in sepsis patients and its significance

To study the effect of anticoagulant therapy with low molecular weight heparin (LMWH) on coagulation and inflammation markers in sepsis patients. A prospective randomized controlled trial ( RCT ) was conducted. Eighty-seven patients suffering from septic shock undergoing mechanical ventilation in Department of Critical Care Medicine of Subei People's Hospital from June 2012 to September 2014 were enrolled. The hemodynamic changes before and after PLR were monitored by pulse indicated continuous cardiac output ( PiCCO ) and PVI monitoring. Responsive group: positive fluid response was defined as an increase in cardiac index ( CI )≥10% after PLR. Unresponsive group: negative fluid response was defined as an increase in CI<10% after PLR. The hemodynamic parameters, including heart rate ( HR ), mean arterial pressure ( MAP ), central venous pressure ( CVP ), stroke volume variation ( SVV ), CI and PVI, and the changes in cardiac parameters (ΔHR, ΔMAP, ΔCVP, ΔSVV, ΔCI, and ΔPVI ) before and after PLR were determined. The relations between hemodynamic parameters and their changes with ΔCI were analyzed by the Pearson analysis. The role of the parameters for volume responsiveness prediction was evaluated by receiver operating characteristic ( ROC ) curves. There were no significant differences in values of all parameters, including CD62p, D-dimmer, IL-6, TNF-α, and APACHE II score at 1 day of treatment. The values of all parameters in observation group were gradually decreased. CD62p at 3 days of treatment and D-dimmer, IL-6, TNF-α, and APACHE II score at 5 days of treatment were significantly lower than those at 1 day of treatment. The values in the control group were decreased at first and then increased, as D-dimmer, IL-6 and TNF-α were significantly higher on the 5th day than those at 1 day of treatment. Compared with control group, CD62p, D-dimmer, IL-6, TNF-α and APACHE II score on the 7th day of treatment were significantly lowered in observation group [CD62 (μg/L): 22.64±2.88 vs. 31.52±2.81, D-dimmer (g/L): 1.32±0.46 vs. 4.79±0.82, IL-6 (ng/L): 5.84±1.87 vs. 49.64±3.12, TNF-α (ng/L): 21.04±3.15 vs. 130.58±6.26, APACHE II score: 9.71±2.02 vs. 14.17±2.38, all P < 0.05]. Correlation analysis showed that in observation group, CD62p, D-dimmer, IL-6, and TNF-α were positively correlated with APACHE II score (r value was 0.907, 0.868, 0.880, 0.693, respectively, all P=0.000). The incidence of MODS in observation group was significantly lower than that in the control group [26.7% (8/30) vs. 46.7% (14/30), χ (2)=3.943, P = 0.028]. LMWH, which was given early in sepsis, can significantly down-regulate the expression of CD62p, D-dimmer, IL-6 and TNF-α, and reduce the incidence of MODS. Some indicators regarding coagulation and inflammation can be used as supplementary indicators to severity scores, and it may be able to improve the accuracy of scoring systems for sepsis.