Continuous Cardiac Output Research Articles

The Ability of Stroke Volume Variation Measured by a Noninvasive Cardiac Output Monitor to Predict Fluid Responsiveness in Mechanically Ventilated Children

Continuous noninvasive cardiac output monitoring (NICOM) is a clinically useful tool in the pediatric setting. This study compared the ability of stroke volume variation (SVV) measured by NICOM with that of respiratory variations in the velocity of aortic blood flow (△Vpeak) and central venous pressure (CVP) to predict of fluid responsiveness in mechanically ventilated children after ventricular septal defect repair. The study investigated 26 mechanically ventilated children after the completion of surgery. At 30min after their arrival in an intensive care unit, a colloid solution of 10ml/kg was administrated for volume expansion. Hemodynamic variables, including CVP, stroke volume, and △Vpeak in addition to cardiac output and SVV in NICOM were measured before and 10min after volume expansion. The patients with a stroke volume increase of more than 15% after volume expansion were defined as responders. The 26 patients in the study consisted of 13 responders and 13 nonresponders. Before volume expansion, △Vpeak and SVV were higher in the responders (both p values <0.001). The areas under the receiver operating characteristic curves of △Vpeak, SVV, and CVP were respectively 0.956 (95% CI 0.885-1.00), 0.888 (95% CI 0.764-1.00), and 0.331 (95% CI 0.123-0.540). This study showed that SVV by NICOM and △Vpeak by echocardiography, but not CVP, reliably predicted fluid responsiveness during mechanical ventilation after ventricular septal defect repair in children.

Evaluation of the estimated continuous cardiac output monitoring system in adults and children undergoing kidney transplant surgery: a pilot study

Evaluation of the estimated continuous cardiac output (esCCO) allows non-invasive and continuous assessment of cardiac output. However, the applicability of this approach in children has not been assessed thus far. We compared the correlation coefficient, bias, standard deviation (SD), and the lower and upper 95 % limits of agreement for esCCO and dye densitography-cardiac output (DDG-CO) measurements by pulse dye densitometry (PDD) in adults and children. On the basis of these assessments, we aimed to examine whether esCCO can be used in pediatric patients. DDG-CO was measured by pulse dye densitometry (PDD) using indocyanine green. Modified-pulse wave transit time, obtained using pulse oximetry and electrocardiography, was used to measure esCCO. Correlations between DDG-CO and esCCO in adults and children were analyzed using regression analysis with the least squares method. Differences between the two correlation coefficients were statistically analyzed using a correlation coefficient test. Bland-Altman plots were used to evaluate bias and SD for DDG-CO and esCCO in both adults and children, and 95 % limits of agreement (bias ± 1.96 SD) and percentage error (1.96 SD/mean DDG-CO) were calculated and compared. The average age of the adult patients (n = 10) was 39.3 ± 12.1 years, while the average age of the pediatric patients (n = 7) was 9.4 ± 3.1 years (p < 0.001). For adults, the correlation coefficient was 0.756; bias, -0.258 L/min; SD, 1.583 L/min; lower and upper 95 % limits of agreement for DDG-CO and esCCO, -3.360 and 2.844 L/min, respectively; and percentage error, 42.7 %. For children, the corresponding values were 0.904; -0.270; 0.908; -2.051 and 1.510 L/min, respectively; and 35.7 %. Due to the high percentage error values, we could not establish a correlation between esCCO and DDG-CO. However, the 95 % limits of agreement and percentage error were better in children than in adults. Due to the high percentage error, we could not confirm a correlation between esCCO and DDG-CO. However, the agreement between esCCO and DDG-CO seems to be higher in children than in adults. These results suggest that esCCO can also be used in children. Future studies with bigger study populations will be required to further investigate these conclusions.

Study of changes in extravascular lung water index of patients suffered from H7N9 avian influenza with acute respiratory distress syndrome

To analyze the characteristic of changes in extravascular lung water index (EVLWI) of H7N9 avian influenza patients who complicated with acute respiratory distress syndrome (ARDS), and to approach the relevance between EVLWI and severity, pulmonary oxygenation in patients with lung injury. Four H7N9 avian influenza patients administered from April to June in 2013 in First Affiliated Hospital of Nanchang University were studied. The patients who suffered from severe ARDS were administered with low tide volume ventilation plus positive end-expiratory pressure (PEEP), namely protected ventilation strategy, with monitoring hemodynamic parameters and EVLWI through pulse-indicated continuous cardiac output (PiCCO) catheter. During ventilation, patients' parameters, such as PEEP, fraction of inspired oxygen (FiO2), arterial partial pressure of oxygen (PaO2), oxygenation index (PaO2/FiO2), cardiac index (CI), systemic vascular resistance index (SVRI), pulmonary vascular resistance index (PVRI), EVLWI, and central venous pressure (CVP) were collected. All 4 H7N9 avian influenza patients were complicated with ARDS, 2 patients were classified to severe ARDS and administered with comprehensive therapies, specially protected ventilation strategy; ventilation duration was 9 days and 30 days respectively, and PiCCO monitoring was 9 days and 21 days respectively. EVLWI of 2 patients on the 1st, 2nd, 3rd day was 10.0±3.2 ml/kg, 12.0±2.9 ml/kg, 14.0±4.2 ml/kg, and 24.0±6.7 ml/kg, 24.0±6.1 ml/kg, 23.0±5.8 ml/kg, respectively. As their conditions became better, patients' EVLWI decreased to 5.5±2.7 ml/kg and 7.0±3.0 ml/kg, respectively at weaning. PEEP and FiO2 of 2 patients were down-regulated, PaO2/FiO2 increased to 334±64 mm Hg and 142±53 mm Hg at weaning. However, no significant changes in CI, SVRI, PVRI and CVP in the 2 patients were observed. EVLWI increases when H7N9 avian influenza patients are complicated with severe ARDS. As the conditions get better, EVLWI returns to normal value gradually. There is relevance between the motive changes in EVLWI and severity of ARDS and pulmonary oxygenation.

Study on factors influencing the failure of PiCCO on weaning from mechanical ventilation in ARDS patients

Objective To analyze and evaluate the variability and effects of extra-vascular lung water index (EVLWI),preload and cardiac function on weaning from mechanical ventilation in patients with ARDS.Methods All patients suffered from ARDS were treated with mechanical ventilation and monitored by pulse indicator continuous cardiac output (PiCCO) till they reached weaning criteria,then spontaneous breathing trial,weauing and extubation were performed in succession.The enrolled patients were divided into two groups,namely success group and failure group according to clinic outcome after weaning in 48 hours.EVLWI,preload markers such as global end-diastolic volume index (GEDI),intrathoracic blood volume index (ITBI),and cardiac function such as cardiac output and cardiac index were compared between two groups before weaning (T0),0.5 h after weaning (T1),0.5 h after extubation (T2),and observational endpoints (T3) (Observational eudpoint is defined as “ before re-intubation” in failure group or 48 h after extubation in succcss group).Results A total of 69 ARDS patients were enrolled from August 2010 to September 2012.Compared with variables before weaning,GEDI and ITBI were markedly higher observed at T1 and T2 (P ＜ 0.05).EVLWI was significantly increased at T1,T2 and T3 (P ＜ 0.01).Increased pulmonary vascular permeability index (PVPI) were also found at T3 (P ＜ 0.05).Compared with the success group,GEDI and ITBI in the failure group were higher at T1,T2 and T3 (P ＜0.05),and EVLWI were significant higher at T2 and T3 (P ＜ 0.05),and increased PVPI at 33 (P ＜0.05).Conclusions Additional volume load may result from weaning off mechanical ventilation and extubation in ARDS patients,and can induce high pulmonary vascular permeability causing pulmonary edema and weaning failure.Therefore,monitoring of EVLWI and preload markers could be valuable to predicting the prognosis of weaning from mechanical ventilation. Key words: Acute respiratory distress syndrome ; Mechanical ventilation; Pulse indicator continuous cardiac output ; Extravascular lung water index

Noninvasive Continuous Cardiac Output by the Nexfin Before and After Preload-Modifying Maneuvers

The Nexfin uses an uncalibrated pulse contour method for the continuous measurement of cardiac output (CO) in a totally noninvasive manner. Since the accuracy of pulse contour methods and their ability to track changes in CO have been repeatedly questioned, we have compared the CO measured by the Nexfin (NAPCO) with the CO measured by the pulmonary artery catheter (PACCO) in cardiosurgical patients before and after preload-modifying maneuvers. Twenty-eight patients who underwent on-pump cardiac surgery, of whom 18 were receiving vasopressor and/or inotropic therapy, were studied during the first postoperative hours. Preload modification, in the form of either a fluid challenge or a passive leg raising maneuver, was done whenever clinically indicated, with PACCO and NAPCO being simultaneously measured before and after each intervention. A fluid challenge was administered to 22 patients, and the passive leg raising maneuver was performed in 6 patients. These interventions were repeated in 19 patients producing a total of 47 pairs of measurements. At baseline, mean (±SD) CO was 4.9 ± 1.1 and 5.0 ± 1.4 L·min(-1), for the PACCO and NAPCO, respectively, bias 0.1 ± 1.0, 95% prediction interval -2.5 to 2.4 L·min(-1), and 39% of error. After preload modification, the mean CO was 5.6 ± 1.3 and 5.6± 1.5 L·min(-1) for the PACCO and NAPCO, respectively, bias -0.0 ± 1.1, 95% prediction interval -2.6 to 2.7 L·min(-1), and 38% of error. The correlation coefficients (r) between the PACCO and NAPCO before and after preload modification were 0.71 (95% confidence interval [95% CI], 0.53-0.82) and 0.70 (95% CI, 0.52-0.82), respectively. Preload modification induced similar absolute changes in PACCO and NAPCO (r = 0.9, P < 0.0001). A 4-quadrant scatter plot showed a concordance rate of 100% (95% CI, 80.5%-100%) between the changes in NAPCO and PACCO. Polar plot analysis demonstrated a small polar angle and radial limits of agreement well below the 30° benchmark. The area under a receiver operating characteristic curve, testing the ability of Nexfin to detect an increase of ≥15% in PACCO, was 0.974 (95% CI, 0.93-0.99). Although the Nexfin has limited accuracy when compared with the pulmonary artery catheter, it can reliably track preload-induced changes in CO in stable patients after cardiac surgery in the presence of moderate vasopressor and inotropic therapy. This ability, combined with its total noninvasiveness, fast installation, and ease of use, make the Nexfin a suitable monitor for the perioperative continuous measurement of CO. The reliability of this monitor in tracking the CO when significant changes in peripheral resistance take place still needs to be established.

The pulse pressure/heart rate ratio as a marker of stroke volume changes during hemorrhagic shock and resuscitation in anesthetized swine

Emergency physicians and anesthesiologists need accurate estimates of stroke volume when massive unexpected hemorrhage occurs. Using an animal model of hemorrhagic shock under general anesthesia, we hypothesized that the pulse pressure-heart rate ratio (PP/HR) would be an accurate marker of stroke volume changes during hemorrhage and resuscitation. In 16 swine under bispectral index-controlled, intravenous propofol-remifentanil anesthesia, pressure-controlled hemorrhagic shock was induced to achieve 30 mm Hg of mean arterial pressure, after which treatment was randomized to fluid (HES, n = 4), norepinephrine (NE, n = 4), both (HES + NE, n = 4), or neither (control, n = 4). Pulmonary artery thermodilution continuous cardiac output, stroke volume, and central arterial pressures were recorded at baseline (T0), after 30 minutes (T30) and 60 (T60) minutes of hemorrhage, during treatment (T90 and T120) and after blood retransfusion (T180). At T60, blood withdrawal was 995 (301) mL (38 [8] mL/kg), resulting in a 70% decrease in stroke volume and a 3.3-fold decrease in PP/HR (each p < 0.01). When stroke volume data pointed at T0, T30 and T60 were plotted against the various hemodynamic variables under study, the PP/HR ratio exhibited the strongest relationship to stroke volume (r = 0.72). The area under the receiver operating characteristic curve set to detect a 15% stroke volume decrease was larger for PP/HR (0.95 [0.94-0.97]) than for mean arterial pressure (0.91 [0.89-0.93]) (p < 0.013). During resuscitation in the HES and NE groups, correlation coefficients were significantly higher between stroke volume and PP/HR (0.75 [0.63-0.84] and 0.79 [0.67-0.86]) than between stroke volume and mean arterial pressure (0.52 [0.32-0.67], p = 0.042, and 0.49 [0.28-0.65], p = 0.0018, respectively). The PP/HR ratio was strongly related to stroke volume during hemorrhagic shock and resuscitation in anesthetized swine.

Assessment effect of central venous pressure in fluid resuscitation in the patients with shock: a multi-center retrospective research

Background Central venous pressure (CVP) and intrathoracic blood volume index (ITBVI) were used to assess the fluid status. It has previously been shown that CVP is not as accurate as ITBVI for all the shock patients. We therefore hypothesized that the change of CVP has the ability to predict fluid responsiveness in some clinical cases of shock. Methods From September 1st 2009 to September 1st 2011, sixty-three patients with shock from different Intensive Care Unit (ICU) were collected into this retrospective study. All the patients received fluid challenge strategy (infusing 300 ml hydroxyethyl starch in 20 minutes), were monitored with CVP and pulse-indicated continuous cardiac output (PICCO). The correlation between changes in cardiac index (ΔCI), CVP (ΔCVP) and ITBVI (ΔITBVI) were analyzed. Fluid responsiveness was defined as an increase in CI ≥10%. Receiver operating characteristic (ROC) curves were generated for ΔCVP and ΔITBVI. Results For all the patients, there was no correlation between ΔCI and ΔCVP (P=0.073), but in the subgroup analysis, the correlation between ΔCI and ΔCVP was significant in those younger than 60 years old (P=0.018) and those with hypovolemic shock (P=0.001). The difference of areas under the ROC curves of ΔCVP and ΔITBVI were not statistically significant in the group younger than 60 years old or hypovolemic shock group (P &gt;0.05, respectively). However, no similar results can be found in the group older than 60 years old and the other two shock type groups from ROC curves of ΔCVP and ΔITBVI. Conclusions ΔCVP is not suitable for evaluating the volume status of the shock patients with fluid resuscitation regardless of their condition. However, in some ways, ΔCVP have the ability to predict fluid responsiveness in the younger shock patients or in the hypovolemic shock patients.

Is peripheral arterial waveform analysis continuous cardiac output monitoring useful with assessment of oxygenation status for patients on veno–venous extracorporeal membrane oxygenation?

Is peripheral arterial waveform analysis continuous cardiac output monitoring useful with assessment of oxygenation status for patients on veno–venous extracorporeal membrane oxygenation?

Swan-Ganz 카테터를 이용한 심폐기능 이상 환자의 지속적 심박출량 측정 모듈 개발

This study materialized the new module which enables to measure more precise data than the existing modules in order to examine the cardiac disorder critical patient`s state by using Swan-Ganz Catheter. There was bolus type CO(Cardiac Output) module which measured CO by measuring the blood changes in temperature and recovery time by injecting cold sap into the heart in the past, but recently, it is not used in most of hospitals due to limit of difficulty of continuous monitoring for the patients. To overcome this limit, the continuous cardiac output measurement platform was materialized to enable the continuous monitoring for patients. The wasted cost issues because of introducing the expensive imported equipment to observe the critical patient`s state with abnormal cardiopulmonary function in the hospitals can be solved by using this new module, and the problem of existing modules should be supplemented for more accurate diagnosis by collecting more precise data.

Erroneous continuous cardiac output by calibrated pulse contour analysis

Pulse contour analysis techniques are used for beat-to-beat tracking of cardiac output in critically ill patients. However, an adequate pulse pressure waveform signal and identification of the appropriate (i.e. systolic) part of the waveform by the monitor are crucial for correct calculation of continuous cardiac output. We observed a case where the monitor failed to correctly identify the systolic part of the waveform during tachycardia thus giving false readings. We would like to emphasize the importance of visually checking the waveform for any irregularities that may cause erroneous calculations before initiating a therapy based on these values. One advantage of the system used here is that the part of the pressure curve used for analysis is automatically indicated.

Improvement of Hypovolemic men's and women's orthostatic tolerance by a short exposure to artificial gravity

We used a combination of head up tilt and lower body negative pressure to test the orthostatic tolerance limit (OTL) of nine men and eight women, once following a 90 min exposure to artificial gravity (AG) and once following 90 min of head down bedrest (HDBR) In both cases (21 days apart), subjects were made hypovolemic by low salt diet plus 20 mg intravenous furosemide. Heart rate (from ECG), continuous blood pressure, stroke volume, cardiac output and peripheral resistance (Finometer), middle cerebral artery blood velocity (MCAv, transcranial Doppler), partial pressure of end‐tidal carbon dioxide (ETCO2, Novametrics) and body segmental impedance (UFI THRIM) were measured during supine control, during OTL to presyncope and supine recovery. Orthostatic tolerance on the day of AG exposure was significantly greater than on the day following HDBR (p&lt;0.03), see figure. Mechanisms of improved tolerance on the AG day included higher values of stroke volume and cerebral artery velocity and lower values of blood pressure, peripheral vascular and cerebrovascular resistance in control and during tilt. By the time presyncope was reached, stroke volume was at the same level on each day of study. We conclude that AG exposure prolonged the onset of presyncope by increasing output of the heart and cerebral blood flow. Supported by KY NASA EPSCoR Grant #NNX07AT58A, KY State Matching Grants, NASA JSC Human Research Program and NASA Ames Research Center.

Application of PICCO in the treatment of septic shock patients during CRRT

Objective To explore application of pulse indicator continuous cardiac output(PICCO)in the treatment of septic shock during continuous renal replacement therapy (CRRT).Methods 34 patients with septic shock who underwent CRRT were randomly divided into the control group and the experimental group.Heart rate(HR),mean arterial pressure(MAP)and central venous pressure (CVP) were monitored in the control group.The experimental group were monitored by PICCO technology in addition to conventional monitoring,the hemodynamics parameters were collected such as end-diastolic volume index (GEDI),extravascular lung water index(EVLWI),and systemic vascular resistance index(SVRI),etc.Dehydration volume and supplementary volume were controlled by means of two group's hemodynamics parameters.The change of Acute Physiology And Chronic Health Evaluation-Ⅱ (APACHE Ⅱ),lactate (Lac),saturation of central venous oxygen(SevO2) and oxygenation index (PaO2/FiO2) were observed.Results After treatment of 72h,the decrease of APACHE Ⅱ and lactate in the experimental group was higher than those in the control group,the increase of ScvO2 in the experimental group was higher than those in the control group,the increase of PaO2/FiO2 in the experimental group was evidently higher than those in the control group.Conclusions During PICCO monitoring technique to guide CRRT therapy in patients with septic shock,the volume status of patients can be accurately controlled,organizational cycle can be improved,oxygenation of lung can be obviously improved,which contributes to treatment of septic shock. Key words: Pulse indicator continuous cardiac output; Hemodynamics; Septic shock; Continuous renal replacement therapy

Factors Affecting Intraoperative Changes in Regional Cerebral Oxygen Saturation in Patients Undergoing Liver Transplantation

BackgroundRegional oxygen saturation (rSO2) is a sensitive marker of cerebral hypoperfusion during liver transplantation. However, bilirubin absorbs near-infrared light, resulting in falsely low rSO2 values. We sought to determine whether rSO2 values vary in response to bilirubin concentrations during liver transplantation and to assess whether rSO2 changes were associated with factors reflecting cerebral oxygen delivery in patients with hyperbilirubinemia. MethodsMeasurements of rSO2 values continuous cardiac output (CO), mean arterial pressure, central venous pressure, body temperature, arterial blood gas analysis, and laboratory parameters were simultaneously performed at 1 hour after the surgical incision (baseline) and at 3 predetermined times during the anhepatic and neohepatic phases in 95 end-stage liver disease patients including 67 males of Child A/B/C/29/29/37 categories respectively. Relationships between changes in parameters were evaluated by correlation and multivariate regression analyses. ResultsThe 273 measurements revealed changes in rSO2 (range, −18% to 40%) to correlate significantly with alterations in hemoglobin (Hb), serum glucose, lactate, prothrombin time, pH, partial arterial CO2 pressure (PaCO2), and CO, but not with serum total bilirubin (TB). Multivariate linear regression analysis revealed that changes in Hb, CO, PaCO2, and pH were independent of rSO2 changes during liver transplantation. ConclusionsOur findings showed that rSO2 changes were independently associated with factors reflecting cerebral oxygen delivery, such as Hb, CO, PaCO2, and pH, whereas rSO2 values did not correlate with changes in bilirubin concentrations, indicating that rSO2 changes reveal cerebral oxygen balance regardless of TB levels among patients undergoing liver transplantation.

Clinical value of extravascular lung water and preload parameters in weaning of mechanical ventilation in patients with septic shock

To investigate the values of extravascular lung water and preload parameters of weaning from mechanical ventilation on patients with septic shock. A prospective study was conducted. A total of 52 septic shock patients with mechanical ventilation were enrolled from January 2010 to July 2012. All patients were treated and monitored by pulse induced continuous cardiac output (PiCCO) till they reached weaning criteria, and then spontaneous breathing trial (SBT), weaning, and extubation were performed in turn. The enrolled patients were divided into two groups including successful weaning group (n=38) and weaning failure group (n=14) according to clinical manifestations during 48 hours after weaning. Extravascular lung water index (EVLWI), preload parameters such as global end diastolic volume index (GEDVI) and intra-thoracic blood volume index (ITBVI), pulmonary vascular permeability index (PVPI) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) were compared at the time before weaning, 0.5 hour after weaning, 0.5 hour after extubation, and time of weaning failure or 48 hours after weaning. The patients in weaning failure group were sub-divided into high PVPI group (PVPI≥1.5 ml/m(2)) and low PVPI group (PVPI<1.5 ml/m(2)), the NT-proBNP and pulmonary blood volume (PBV) were compared between two groups. Before weaning, there was no statistical difference in NT-proBNP, volume parameters and EVLWI between two groups. EVLWI, GEDVI, ITBVI, PVPI and log NT-proBNP were gradually increased after weaning and extubation in two groups. The EVLWI, PVPI and log NT-proBNP were significantly higher at end point of observation in weaning failure group compared with those in successful weaning group (EVLWI: 12.81±2.13 ml/kg vs. 8.48±1.53 ml/kg, PVPI: 2.79±1.29 ml/m(2) vs. 2.19±0.94 ml/m(2), log NT-proBNP: 3.72±0.35 vs. 3.44±0.28, P<0.05 or P<0.01). GEDVI, ITBVI at 0.5 hour after weaning and end point of observation in weaning failure group were significantly higher than those in successful weaning group (0.5 hour after extubation: GEDVI 986.29±166.44 ml/m(2) vs. 856.47±149.15 ml/m(2), ITBVI: 1171.07±167.03 ml/m(2) vs. 1045.79±146.09 ml/m(2); end point of observation: GEDVI 957.00±67.25 ml/m(2) vs. 816.86±27.58 ml/m(2), ITBVI: 1184.29±209.68 ml/m(2) vs. 993.79±168.90 ml/m(2), P<0.05 or P<0.01). Sub-analysis showed that in weaning failure group, higher log NT-proBNP and PBV were found in patients with low PVPI compared with those with high PVPI (log NT-proBNP: 4.02±0.11 vs. 3.71±0.23, PBV: 507.19±25.72 ml vs. 347.85±47.52 ml, P<0.05 and P<0.01). Increased EVLW is the reason of pulmonary edema caused by weaning in septic shock patients, to which both hydrostatic and pulmonary permeability may contribute, and the latter could be more important. Monitoring preload parameters could help distinguish the mechanism of pulmonary edema after weaning, which may be useful in treatment.

Use of the PiCCO system in critically ill patients with septic shock and acute respiratory distress syndrome: a study protocol for a randomized controlled trial

BackgroundHemodynamic monitoring is very important in critically ill patients with shock or acute respiratory distress syndrome(ARDS). The PiCCO (Pulse index Contour Continuous Cardiac Output, Pulsion Medical Systems, Germany) system has been developed and used in critical care settings for several years. However, its impact on clinical outcomes remains unknown.Methods/designThe study is a randomized controlled multi-center trial. A total of 708 patients with ARDS, septic shock or both will be included from January 2012 to January 2014. Subjects will be randomized to receive PiCCO monitoring or not. Our primary end point is 30-day mortality, and secondary outcome measures include ICU length of stay, days on mechanical ventilation, days of vasoactive agent support, ICU-free survival days during a 30-day period, mechanical-ventilation-free survival days during a 30-day period, and maximum SOFA score during the first 7 days.DiscussionWe investigate whether the use of PiCCO monitoring will improve patient outcomes in critically ill patients with ARDS or septic shock. This will provide additional data on hemodynamic monitoring and help clinicians to make decisions on the use of PiCCO.Trial registrationhttp://www.clinicaltrials.gov NCT01526382

Hemodynamic Changes during Off-Pump Coronary Ar-tery Bypass Graft Surgery: Experience Using Pericardial Bands for Target Stabilization

Background: The off-pump coronary artery bypass graft surgery (OPCAB) may produce significant hemodynamic instability necessitating conversion to on-pump surgery. This study evaluated the hemodynamic parameters in patients undergoing OPCAB using pericardial bands for stabilization of the coronary target sites. Methods: In 250 patients undergoing OPCAB the hemodynamic parameters including continuous cardiac output and systemic venous oxygen saturation (SvO2) were recorded at baseline after pericardiotomy, during each coronary artery anastomosis at 3, 5, 10, 15 min, and after release of the pericardial bands used for target stabilization. Vasopressors were used to maintain mean arterial pressure (MAP) > 60 mmHg. Results: SvO2 and cardiac index (CI) decreased significantly after target stabilization and during all coronary anastomoses with greater decreases noted during obtuse marginal branch of left circumflex (OM) anastomosis. The MAP and heart rate were maintained without significant change but central venous pressure increased significantly during all coronary anastomoses. The significant increase in pulmonary capillary wedge pressure and mean pulmonary artery pressure were noted only during anastomosis of the left anterior descending artery. The highest dose of vasopressor was used during OM anastomosis. Conclusions: During OPCAB surgery using pericardial bands for coronary target stabilization, MAP was maintained constantly, but SvO2 and CI decreased immediately after target stabilization and reduced further during all coronary artery anastomoses. During OM anastomosis SvO2 and CI were significantly lower as compared to that of LAD and right coronary artery. Careful monitoring and management of hemodynamic variables are warranted to avoid conversion to on-pump technique.

Can We Obtain a Noninvasive and Continuous Estimation of Cardiac Output? Comparison Between Three Noninvasive Methods

Cardiac output (CO) is often desirable for assessing the hemodynamic condition of a patient, especially in critically ill cardiac patients. Various noninvasive methods are available for this purpose. Inert gas rebreathing (IGR) and 2D-Doppler echocardiography methods have been validated. Based on the relationship between pulse wave transit time and stroke volume, the VISMO® provides an estimated continuous cardiac output (esCCO) measurement using only an electrocardiogram, pulse oximeter wave, and cuff arterial blood pressure. Doppler echocardiography is being currently used in every day practice in this setting and IGR is a validated method, thus we wanted to assess the agreement between these 3 methods for noninvasive CO calculation and reproducibility of esCCO. Patients followed in our cardiology department received on the same day a CO analysis by esCCO, Doppler echocardiography and IGR. Thirty-four patients were included (16 women, mean age 65 ± 15 years). Bland and Altman plots showed a good agreement between IGR and 2D-Doppler echocardiography (bias = 0.31 L/minute). Though there was also an agreement between esCCO and the other 2, the bias was rather large: 1.18 L/minute with IGR and 1.51 L/min with 2D-Doppler echo. The intraclass correlation coefficient was poor whatever the methods. However, esCCO had a satisfactory reproducibility and accuracy compared rather well with the other 2. This method could be suitable for patient screening and monitoring.

運動負荷中の心電図とSpO&lt;sub&gt;2&lt;/sub&gt; 脈波を用いた非侵襲連続心拍出量測定のエコードップラーに対する一致度とトレンドの追従性

A new technology called estimated continuous cardiac output (esCCO) uses pulse wave transit time (PWTT) obtained from an electrocardiogram and pulse oximeter to measure cardiac output (CO) noninvasively and continuously. This study was performed to evaluate the accuracy of esCCO during exercise testing. We compared esCCO with CO measured by echo Doppler aortic velocity-time integral (VTIao_CO). The correlation coefficient between esCCO and VTIao_CO was r = 0.87 (n = 72). Bias and precision were 0.33 ± 0.95 L/min with a percentage error of 30.2%. And the correlation coefficient between change in esCCO and change in VTIao_CO was r = 0.75 (n = 70). The esCCO could detect change in VTIao_CO larger than 1 L/min with a concordance rate of 88.2%. The areas under ROC curves to detect VTIao_CO changes more than 15% and 30% were 0.81 and 0.91, respectively. Polar plots show that the mean polar angle was 2.2° and radial limits of agreement were ±43.6°. The trending ability of esCCO is comparable with that of currently available arterial waveform analysis methods. In this study, the validity of esCCO during exercise testing was assessed and shown to be acceptable with respect to agreement and trending ability compared with the echo Doppler.

Fluid resuscitation strategy in septic shock following urinary infection with severe pulmonary capillary leakage

To characterize septic shock following urinary infection with severe pulmonary capillary leakage, and to evaluate the fluid therapy on treatment of hypovolemic shock and the role of transpulmonary thermodilution technique with pulse induced continuous cardiac output (PiCCO) monitoring. A retrospective study was conducted. Eight patients surviving septic shock following urinary infection with severe pulmonary capillary leakage were enrolled, and all of them underwent PiCCO monitoring in the intensive care unit (ICU) when the diagnosis was established. The monitoring started at admission, and ended when shock was corrected or transferred from ICU. The clinical data including general end diastolic volume index (GEDVI), extravascular lung water index (EVLWI), input and output volume of fluid, net fluid balance, oxygenation index (PaO2/FiO2), the level of arterial blood lactic acid, and chest X ray were collected and analyzed retrospectively the characteristics of septic shock following urinary infection, and the role of PiCCO monitoring in fluid resuscitation. Septic shock following urinary infection occurred in a median of 4.5 days in 8 patients after renal and ureteric calculi lithotripsy, accompanied with severe pulmonary vessel effusion and hypoxemia in different degrees. The mean value of EVLWI was (22±7) ml/kg, and the PaO2/FiO2 (164±82) mm Hg at the time of admission to ICU. Conservative fluid resuscitation strategy was adopted in management of septic shock with severe pulmonary capillary leakage, the mean fluid input in 8 patients was (2412±1121) ml/d, and the net fluid balance -553 ml/d, and the central venous pressure (CVP) and GEDVI were maintained at levels of (9±3) mm Hg and (749±236) ml/m(2) respectively. Diuretics were administered to 6 patients and the mean dosage of fursemide was (264±133) mg. Norepinephrine and dobutamine infusion were given to 7 patients to maintain blood pressure at normal range for (4±1) days. Seven patients were mechanically ventilated, and the mean length of ventilation was (8±6) days. All of the 8 patients survived from septic shock after fluid resuscitation therapy, with the mean level of EVLWI decreased gradually to (11±3) ml/kg, and the lung effusion was absorbed significantly as shown in chest X ray. The mean length of ICU stay was (17±11) days. Pearson correlate analysis showed EVLWI was significantly correlated with PaO(2)/FiO(2) and the levels of artery blood serum lactate, with r -0.91 and 0.70 respectively (both P<0.05). Successful management of septic shock following urinary infection with severe pulmonary vascular leakage is based on accurate assessment of blood volume status, especially the degree of EVLWI, emphasis on prevention of EVLWI increase, and adoption of conservative fluid resuscitation strategies according to hemodynamic monitoring parameters. PiCCO monitoring is a useful tool in assessment of the blood volume status and management of fluid resuscitation in patients with urinary lithotripsy-associated septic shock complicated with severe pulmonary edema.

Mean arterial pressure as an indicator of fluid responsiveness in patients with septic shock

To assess the value of mean arterial pressure (MAP) as an indicator for fluid responsiveness in patients with septic shock. A retrospective analysis of clinical data of 68 patients with septic shock receiving volume resuscitation in intensive care unit (ICU) of Drum-tower Hospital Affiliated to Medical School of Nanjing University from June 2011 to February 2012 was conducted. The changes in heart rate (HR), MAP, systolic arterial pressure (SBP), diastolic arterial pressure (DBP), pluse pressure (PP), central venous pressure (CVP) were recorded before and after volume resuscitations. Cardiac index (CI), intrathoracic blood volume index (ITBVI), systemic vessel resistance index (SVRI) and extravascular lung water index (EVLWI) were evaluated by using the thermodilution technique of pulse induced continuous cardiac output (PiCCO). All the patients were divided into two groups, responded group (ΔCI%≥10%) and the unresponded group (ΔCI%<10%), according to the change in CI (ΔCI%). Then the patients were divided into two subgroups, namely low MAP group(LMAP, MAP≤65 mm Hg) and high MAP group(HMAP, MAP>65 mm Hg), according to the initial value of MAP. Then compared the changes in hemodynamic variables before and after volume resuscitation in each subgroup and assess the correlation between the changes in MAP (ΔMAP%) and ΔCI%. Forty-four (64.7%) patients responded to the fluid challenge according to the predetermined criteria, SBP, DBP, MAP, PP, CI, CVP, ITBVI were increased significantly (SBP: 126.5±23.8 mm Hg vs. 110.7±20.2 mm Hg, DBP: 58.1±14.8 mm Hg vs. 52.8±13.5 mm Hg, MAP: 80.3±19.2 mm Hg vs. 70.1±15.8 mm Hg, PP: 68.2±18.7 mm Hg vs. 58.0±15.8 mm Hg, CI: 70.0±21.7 ml×s(-1)×m(-2) vs. 53.3±20.0 ml×s(-1)×m(-2), CVP: 13.0±4.5 mm Hg vs. 10.2±4.4 mm Hg, ITBVI: 909.1±248.7 ml/m(2) vs. 773.5±220.7 ml/m(2), all P<0.01), and SVRI was decreased significantly (130.9±47.7 kPa×s×L(-1)×m(-2) vs. 157.1±59.1 kPa×s×L(-1)×m(-2), P<0.01). HR and EVLWI did not change significantly. There was no significant correlation between ΔMAP% and ΔCI% in all the patients (r=0.266,P=0.054). In the sub-group of LMAP (n=39), ΔMAP% was positively correlated with ΔCI% (r=0.473, P=0.03), the under the receiver operating characteristic curve (ROC curve, AUC) was 0.763, 95% confidence interval (95%CI) 0.554 - 0.973, P=0.231. However, there was no significant correlation between the ΔMAP% and ΔCI% (r=-0.088, P=0.633) in the sub-group of HMAP (n=29). MAP can be used as an indicator of fluid responsiveness when the initial value of MAP was at a relative low level (MAP≤65 mm Hg) in patients with septic shock.