PURPOSE: The most common method of monitoring cardiac output (CO) is thermodilution using pulmonary artery catheter (PAC), but this method is associated with complications. Impedance cardiography (ICG) is a non-invasive CO monitoring technique. This study compared the accuracy and efficacy of ICG as a non-invasive cardiac function monitoring technique to those of thermodilution and arterial pressure contour. MATERIALS AND METHODS: Sixteen patients undergoing liver transplantation were included. Cardiac index (CI) was measured by thermodilution using PAC, arterial waveform analysis, and ICG simultaneously in each patient. Statistical analysis was performed using intraclass correlation coefficient (ICC) and Bland-Altman analysis to assess the degree of agreement. RESULTS: The difference by thermodilution and ICG was 1.13 L/min/m², and the limits of agreement were −0.93 and 3.20 L/min/m². The difference by thermodilution and arterial pressure contour was 0.62 L/min/m², and the limits of agreement were −1.43 and 2.67 L/min/m². The difference by arterial pressure contour and ICG was 0.50 L/min/m², and the limits of agreement were −1.32 and 2.32 L/min/m². All three percentage errors exceeded the 30% limit of acceptance. Substantial agreement was observed between CI of thermodilution with PAC and ICG at preanhepatic and anhepatic phases, as well as between CI of thermodilution and arterial waveform analysis at preanhepatic phase. Others showed moderate agreement. CONCLUSION: Although neither method was clinically equivalent to thermodilution, ICG showed more substantial correlation with thermodilution method than with arterial waveform analysis. As a non-invasive cardiac function monitor, ICG would likely require further studies in other settings.
Arterial Pressure ; Cardiac Output ; Cardiography, Impedance ; Catheters ; Electric Impedance ; Humans ; Liver Transplantation ; Methods ; Pulmonary Artery ; Thermodilution

OBJECTIVE: To assess the differences between ultrasound cardiac output monitor (USCOM) and thermodilution (TD) systematically in cardiac function monitoring of critically ill patients. METHODS: The Chinese and English literatures about the clinical trials which using USCOM and TD to monitor cardiac function published in CNKI, Wanfang database, China biomedical literature database, VIP database, China Clinical Trial Registration Center, PubMed, Embase and Cochrane Library were searched by computer from the establishment to December 2018. Some indicators, like cardiac output (CO), cardiac index (CI), stroke volume (SV) and other parameters were used to evaluate cardiac function. Literature search, quality evaluation and data extraction were conducted independently by two authors. The tailored Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) was used for literature quality evaluation. EndNote X6 was used for literature screening and management. RevMan 5.3 was used for Meta-analysis. Funnel chart analysis was used for publication bias. RESULTS: A total of 26 studies involving 772 patients were included. Among them, there were 5 literatures found that the agreements of cardiac function between the USCOM and TD methods were poor. Meta-analysis showed that there was no significant difference between the two methods in CO and CI monitoring [CO: mean difference (MD) = -0.06, 95% confidence interval (95%CI) was -0.17 to 0.05, P = 0.31; CI: MD = -0.04, 95%CI was -0.13 to 0.05, P = 0.38]. Subgroup analysis of different TD methods [pulmonary artery catheter (PAC), pulse indicator continuous cardiac output (PiCCO)] and different windows of USCOM ultrasonic probe [aorta (AA), pulmonary artery (PA)] in CO monitoring was not shown significant difference yet (PAC: MD = -0.07, 95%CI was -0.18 to 0.04, P = 0.23; PiCCO: MD = 0.09, 95%CI was -0.31 to 0.50, P = 0.65; AA windows: MD = -0.14, 95%CI was -0.31 to 0.02, P = 0.09; PA windows: MD = -0.00, 95%CI was -0.15 to 0.14, P = 0.95; AA/PA windows: MD = 0.23, 95%CI was -0.40 to 0.86, P = 0.47). However, the difference in SV was statistically significant between the USCOM and TD method (MD = 1.48, 95%CI was 0.04 to 2.92, P = 0.04). Funnel chart showed that the literature distribution of CO and CI monitoring were basically symmetrical, indicating that the bias of literature publication is small. CONCLUSIONS USCOM has good consistency with TD method in monitoring the cardiac function parameters of CO and CI, and different windows of ultrasonic probe of USCOM have no significant influence on the monitoring results, but there is significant difference in the consistency of the two methods in SV monitoring.
Cardiac Output ; China ; Humans ; Monitoring, Physiologic ; Thermodilution ; Ultrasonography

OBJECTIVETo investigate the effect of atrial fibrillation on the accuracy of parameters monitored by transpulmonary thermodilution method.

METHODSTotally 12 patients from emergency intensive care unit with paroxysmal atrial fibrillation were enrolled. The hemodynamic parameters such as heart rate, mean arterial pressure, cardiac index, systemic vascular resistance index, intrathoracic blood volume index, and extravascular lung water index were monitored by transpulmonary thermodilution method before paroxysmal atrial fibrillation and during atrial fibrillation, the number of B-lines was detected by lung ultrasonography before and during paroxysmal atrial fibrillation. The changes of all the parameters were analyzed.

RESULTSWhen the paroxysmal atrial fibrillation happened, the heart rate increased significantly [(123.3±20.0) beat/min vs. (98.9±12.3) beat/min, P=0.006]; the mean arterial pressure [(86.9±10.2) mmHg vs. (93.0±12.5) mmHg, P=0.058], cardiac index [(2.82±0.62) L/(min·m(2)) vs. (3.31±1.02) L/(min·m(2)), P=0.058] and systemic vascular resistance index [(2254±947) dyn·s·cm(-5)·m(2) vs. (2302±828) dyn·s·cm(-5)·m(2), P=0.351] had no obvious change; however, the intrathoracic blood volume index significantly increased [(1333±90) ml/m(2) vs. (937±111) ml/m(2), P<0.001]; extravascular lung water index also increased significantly [(16.1±1.1) ml/kg vs. (6.5±1.9) ml/kg, P<0.001]. No significant difference was found in the number of B-lines detected by lung ultrasonography before and during atrial fibrillation (10.0±4.2 vs. 9.4±4.4, P=0.180).

CONCLUSIONBoth intrathoracic blood volume and extravascular lung water monitored by transpulmonary thermodilution method were overvalued during paroxysmal atrial fibrillation, which may mislead the clinical judgment and decision-making.

Atrial Fibrillation ; physiopathology ; Blood Pressure ; Blood Volume ; Cardiac Output ; Extravascular Lung Water ; Heart Rate ; Hemodynamics ; Humans ; Intensive Care Units ; Thermodilution ; Vascular Resistance

Pulmonary edema frequently occurs after severe burn. It not only impairs pulmonary function directly, but also can induce or exacerbate other pulmonary complications such as lung infection, acute lung injury ( ALI), and ARDS. Extravascular lung water (EVLW) is closely related to the pulmonary edema. Dynamical monitor of EVLW has been used to predict and quantify the degree of pulmonary edema clinically. This review focuses on the recent progresses at home and abroad on the formation mechanism, monitoring approach, and prevention and treatment of EVLW after severe burn injury.
Acute Lung Injury ; etiology ; physiopathology ; Burns ; Extravascular Lung Water ; Humans ; Pulmonary Edema ; diagnosis ; etiology ; Severity of Illness Index ; Shock, Septic ; complications ; physiopathology ; Thermodilution ; Trauma Severity Indices

OBJECTIVETo study the accuracy of pulse contour cardiac output (PCCO) during blood volume change.

METHODSHemorrhagic shock model was made in twenty dogs followed by volume resuscitation. Two PiCCO catheters were placed into each model to monitor the cardiac output (CO). One of catheters was used to calibrate CO by transpulmonary thermodilution technique (COTP) (calibration group), and the other one was used to calibrate PCCO (none-calibration group). In the hemorrhage phase, calibration was carried out each time when the blood volume dropped by 5 percents in the calibration group until the hemorrhage volume reached to 40 percent of the basic blood volume. Continuous monitor was done in the none-calibration group.Volume resuscitation phase started after re-calibration in the two groups. Calibration was carried out each time when the blood equivalent rose by 5 percents in calibration group until the percentage of blood equivalent volume returned back to 100. Continuous monitor was done in none-calibration group. COTP, PCCO, mean arterial pressure (MAP), systemic circulation resistance (SVR), global enddiastolic volume (GEDV) were recorded respectively in each time point.

RESULTS(1) At the baseline, COTP in calibration group showed no statistic difference compared with PCCO in none-calibration group (P >0.05). (2) In the hemorrhage phase, COTP and GEDV in calibration group decreased gradually, and reached to the minimum value (1.06 ± 0.57) L/min, (238 ± 93) ml respectively at TH8. SVR in calibration group increased gradually, and reached to the maximum value (5 074 ± 2 342) dyn · s · cm⁻⁵ at TH6. However, PCCO and SVR in none-calibration group decreased in a fluctuating manner, and reached to the minimum value (2.42 ± 1.37) L/min, (2 285 ± 1 033) dyn · s · cm⁻⁵ respectively at TH8. COTP in the calibration group showed a significant statistic difference compared with PCCO in the none-calibration group at each time point (At TH1-8, t values were respectively -5.218, -5.495, -4.639, -6.588, -6.029, -5.510, -5.763 and -5.755, all P < 0.01). From TH1 to TH8, the difference in percentage increased gradually. There were statistic differences in SVR at each time point between the two groups (At TH1 and TH4, t values were respectively 2.866 and 2.429, both P < 0.05, at TH2 - TH3 and TH5 - TH8, t values were respectively 3.073, 3.590, 6.847, 8.425, 6.910 and 8.799, all P < 0.01). There was no statistic difference in MAP between the two groups (P > 0.05). (3) In the volume resuscitation phase, COTP and GEDV in the calibration group increased gradually. GEDV reached to the maximum value ((394±133) ml) at TR7, and COTP reached to the maximum value (3.15 ± 1.42) L/min at TR8. SVR in the calibration group decreased gradually, and reached to the minimum value (3 284 ± 1 271) dyn · s · cm⁻⁵ at TR8. However, PCCO and SVR in the none-calibration group increased in a fluctuating manner. SVR reached to the maximum value (8 589 ± 4 771) dyn · s · cm⁻⁵ at TR7, and PCCO reached to the maximum value (1.35 ± 0.70) L/min at TR8. COTP in the calibration group showed a significant statistic difference compared with PCCO in the none-calibration group at each time point (At TR1-8, t values were respectively 8.195, 8.703, 7.903, 8.266, 9.600, 8.340, 8.938, 8.332, all P < 0.01). From TR1 to TR8, the difference in percentage increased gradually. There were statistic differences in SVR at each time point between the two groups (At TR1, t value was -2.810, P < 0.05, at TR2-8, t values were respectively -6.026, -6.026, -5.375, -6.008, -5.406, -5.613 and -5.609, all P < 0.05). There was no statistic difference in MAP between the two groups (P > 0.05).

CONCLUSIONPCCO could not reflect the real CO in case of rapid blood volume change, which resulting in the misjudgment of patient's condition. In clinical practice, more frequent calibrations should be done to maintain the accuracy of PCCO in rapid blood volume change cases.

Animals ; Blood Volume ; Calibration ; Cardiac Output ; Disease Models, Animal ; Dogs ; Humans ; Monitoring, Physiologic ; Shock, Hemorrhagic ; diagnosis ; Thermodilution

BACKGROUND AND OBJECTIVES: Cardiac troponins are associated with increased mortality, even among patients with no coronary artery disease. Elevated cardiac troponin levels are frequently observed in patients without significant coronary lesions, although the mechanism underlying this finding is unclear. The aim of our study was to evaluate the association between the levels of cardiac troponin and coronary flow reserve (CFR). SUBJECTS AND METHODS: We evaluated serum cardiac troponin-I in 19 patients (9 female; age 61.9+/-10.9 year-old). All patients had an ejection fraction >40% and angiographically normal coronary arteries. Simultaneous measurements of fractional flow reserve (FFR), the index of microcirculatory resistance (IMR), and CFR measurements using an intracoronary temperature- and pressure-sensing guidewire under basal conditions and during maximal hyperemia were performed in three vessels: the left anterior descending artery (LAD), left circumflex artery (LCX) and right coronary artery (RCA). RESULTS: All patients were followed for a median of 13 months. FFR, IMR, and CFR measurements were performed successfully in all subjects. Mean CFRs of LAD, LCX, and RCA were 1.98+/-1.20, 2.75+/-2.11, and 4.44+/-2.51, respectively. Mean IMRs of LAD, LCX and RCA were 33.28+/-18.78, 29.11+/-26.70, and 30.55+/-23.65, respectively. There was a poor correlation between CFR and troponin-I values in each vessel. In selecting the lowest value of CFR in each patient as the corresponding value, the lowest CFR was not associated with troponin-I levels (r=-0.219, p=0.367). CONCLUSION: In patients without significant coronary lesions, the correlation between CFR and troponin-I level was not significant using a thermodilution technique. Further study of a larger population with longer-term follow-up may be needed to more fully understand microvascular dysfunction.
Arteries ; Coronary Artery Disease* ; Coronary Vessels ; Female ; Follow-Up Studies ; Humans ; Hyperemia ; Microvessels ; Mortality ; Thermodilution* ; Troponin I ; Troponin* ; Vascular Resistance

OBJECTIVETo assess the accuracy of cardiac output (CO) measured by transpulmonary thermodilution technique (TPTD)and explore the validity of intrathoracic blood volume index (ITBVI) for assessment of circulatory volume status.

METHODSTen immature pigs with a mean weight of (20.6±1.9)kg were studied during the conditions including normovolemia, hypervolemia, and hypovolemia. Simultaneous CO was measured in each condition using pulmonary artery thermodilution (PATD) method and TPTD. More specifically, CO (COPA) was determined with PATD, while CO (COTP) and ITBVI were determined with TPTD. All measurements were repeated 3 times. Central venous pressure (CVP) and heart rate were measured at the same time. The potential correlations of CVP and ITBVI with cardiac index (CI) and stroke volume index (SVI) in each blood volume status were analyzed.

RESULTSA total of 90 simultaneous measurements of COPA and COTP in 3 different blood volume conditions were made. The correlation coefficient between the two measurements was 0.977 (P<0.001) and the mean difference was (0.25±0.26)L/min (95%CI:0.20-0.30 L/min, P<0.001). The coefficient of variation of COTP was 3.7%, while COPA was 5.4%. Compared with those in normovolemia, CVP and ITBVI in hypervolemia significantly increased (P=0.002, 0.019), ITBVI in hypovolemia decreased significantly (P<0.001), and CVP in hypovolemia decreased insignificantly (P=0.05). Correlation analysis revealed a significant correlation between ITBVI with CI and SVI in normovolemia (r=0.741, P=0.014; r=0.885, P=0.001). In contrast, correlations between CVP with CI and SVI were poor.

CONCLUSIONSTPTD can accurately and precisely measure CO in different blood volume conditions. ITBVI measured by TPTD has better validity for the assessment of circulatory volume status than CVP.

Animals ; Blood Volume ; Cardiac Output ; Swine ; Thermodilution

Cardiac output (CO) monitoring is a crucial part of the hemodynamic status monitoring. So far, thermodilution method, which is clinically recognized as the gold standard method to monitor cardiac output, still has irreplaceable advantages. This paper mainly introduces the use of platform for cardiac output measurement based on thermodilution method, mainly including three parts: the hardware platform, software design and algorithm process. A large amount of test data of this system has been got by CO simulator testing in the laboratory and preliminary clinical tests in the hospital. The testing result showed that using the proposed system can achieve good accuracy and repeatability.
Algorithms ; Cardiac Output ; Hemodynamics ; Humans ; Monitoring, Physiologic ; instrumentation ; methods ; Thermodilution

OBJECTIVETo investigate the clinical value of global end-diastolic volume (GEDV) and intrathoracic blood volume (ITBV) in perioperative monitoring of the cardiac preload in patients undergoing orthotopic liver transplantations (OLT).

METHODSEight ASA III or IV patients aged 42-50 years undergoing OLT without venovenous bypass under general anesthesia were enrolled in this study. Before the induction, a thermodilution femoral artery catheter was inserted into the femoral artery under local anesthesia and connected to a PiCCOplus system to monitor ITBV and GEDV. A CCO catheter was inserted into the right internal jugular vein to monitor the pulmonary artery obstruction pressure (PAOP), central venous press (CVP) and stroke volume (SVPAC). Anesthesia was induced with a combination of midazolam (0.1 mg/kg), propofol (1 mg/kg) and fentanyl (3 microg/kg). Pipecuronium (0.1 mg/kg) was given to facilitate naso-endotracheal intubation. Before anesthesia (T0) and at 10 min before the anhepatic phase (T1), 10 min after anhepatic phase (T2), 10 min after neohepatic phase (T3) and at the end of surgery (T4), all the TPTD and CCO parameters were measured by injecting 10 ml cold saline solution (below 8 degrees celsius;) via the distal port of the central venous catheter.

RESULTSITBV and GEDV at T2 were significantly lower than those at T0, T1, T3 and T4 (P<0.05). SVPAC at T2 was dramatically decreased compared with that at T0 and T1 (P<0.05). The changes in the pressure preload parameters of the pulmonary artery catheter (PAOP and CVP) did not correlate to the changes in SVPAC, whereas the changes in the volume preload parameters (ITBV and GEDV) of the TPTD was significantly correlated to the changes in SVPAC (P<0.01). PAOP and CVP did not correlate to the changes in ITBV and GEDV.

CONCLUSIONITBV and GEDV are more reliable than PAOP and CVP in perioperative monitoring of the cardiac preload in patients undergoing OLT.

Adult ; Blood Volume ; Cardiac Output ; Catheterization, Swan-Ganz ; Central Venous Pressure ; Female ; Humans ; Liver Transplantation ; methods ; Male ; Middle Aged ; Monitoring, Intraoperative ; Stroke Volume ; Thermodilution

BACKGROUND: During coronary anastomosis in off-pump coronary artery bypass surgery (OPCAB), hemodynamic alternations can be induced by impaired diastolic function of the right ventricle. This study was designed to examine the effect of milrinone on right ventricular function and early outcomes in patients undergoing OPCAB. METHODS: Forty patients undergoing OPCAB were randomly assigned in a double-blind manner to receive either milrinone (milrinone group, n = 20) or normal saline (control group, n = 20). Hemodynamic variables were measured after pericardiotomy (T1), 5 min after stabilizer application for anastomosis of the left anterior descending coronary artery (LAD, T2), the obtuse marginalis branch (OM, T3), the right coronary artery (RCA, T4), 5 min after sternal closure (T5), and after ICU arrival. The right ventricular ejection fraction (RVEF) and right ventricular volumetric parameters were also measured using the thermodilution technique. For evaluation of early outcomes, the 30-day operative mortality and morbidity risk models were used. RESULTS: There was no significant difference in hemodynamic variables, including mean arterial pressure, between the 2 groups, except for the cardiac index and RVEF. The cardiac index and RVEF were significantly greater at T3 in the milrinone group than in the control group. CONCLUSIONS: Continuous infusion of milrinone demonstrated a beneficial effect on cardiac output and right ventricular function in patients undergoing OPCAB, especially during anastomosis of the graft to the OM artery, and it had no adverse effect on early outcomes.
Arterial Pressure ; Arteries ; Cardiac Output ; Coronary Artery Bypass, Off-Pump ; Coronary Vessels ; Heart Ventricles ; Hemodynamics ; Humans ; Milrinone ; Pericardiectomy ; Stroke Volume ; Thermodilution ; Transplants ; Ventricular Function, Right