Simultaneous intraoperative measurements of eardiac output were obtained in twenty one patients with thoracic electric bioimpedance(TEB) and transesophageal Doppler, two patients with transesophageal Doppler and thermodilution, one patient with TEB and thermodilution, and three patients with TEB, transesophageal Doppler and thermodilution techniques to evaluate the utility of noninvasive methods. Pairs of measurments were obtained 6S times with TEB and thermodilution, 109 times with transesophageal Doppler and thermodilution, and 373 times with TEB and transesophageal Doppler techniques. Correlation of the measurements was poor, with r=0.39 for TEB and thermodilution, r=0.44 for transesophageal Doppler and thermodilution, and r=0.39 for TEB and transesophageal Doppler. The mean difference between TEB and thermodilution, transesophageal Doppler and thermodilution, and TEB and transesophageal Doppler values was -2.41+/-1.79 L/min(mean+/-SD), -0.98+/-1.70 L/min, and -0.69+/-1.01 L/min, respectively. The scattergrams with confidence band lines showed that 22.0% of the scattergram points fell within +/-20% band and 51.5% within +/-40% band in TEB and thermodilution, 55.0% of the scattergram points fell within +/-20% band and 77.9% within +/-40% band in transesophageal Doppler and thermodilution, and 63.6% of the scattergram points fell within +/-20% band and 90.9 within +/-40% band in TEB and transesophageal Doppler. Therefore, it is concluded that neither noninvasive technique reliably estimated cardiac output as determined by thermodilution.
Cardiac Output* ; Humans ; Thermodilution*

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.

Assessment of aortic regurgutation(AR) by means of color Doppler echocardiaography is known to be a reliable noninvasive measure of regurgutation, and the laboratories grade AR primarily on the basis of the maximal length of the regurgitant jet of color Doppler flow mapping. This paper describes the influence of the cardiac output upon the regurgitant jet length. Twenty seven adult patients with AR were examined. In 17 with mild AR of 27 patients, the perioperative color Doppler control studies of AR were done because mitral valve was replaced only. The regurgitant fraction and volume obtained by the thermodilution and pulse Doppler method were compared with angiographic and color Doppler esimates of severity of AR. The results show that the length of the regurgitant jet of AR by color Doppler study became larger aith indreasing cardiac output in the same patient and correlated well with regurgitant volume rether than regurgitant fraction. Therefore the regurgutant jet length appreared to be influenced by regurgutant volume which was altered by changing caediac output. In conclusion, a color Doppler study allows noninvasive quantitative estimation of severity of AR, and its use should take into account the cardiac output.
Adult ; Aortic Valve Insufficiency* ; Cardiac Output* ; Humans ; Mitral Valve ; 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

BACKGROUND: Discrepancy of central-peripheral arterial pressure after cardiopulmonary bypass may affect the reliability of arterial pressure waveform derived cardiac index (APCI) monitoring. METHODS: In 15 elective cardiac surgeries employing moderate hypothermic cardiopulmonary bypass (CPB), APCI from radial arterial cannula and pulmonary artery catheter derived cardiac index from thermodilution method (PACI) were measured 1) after anesthesia induction (T1), 2) before CPB (T2), 3) immediately after CPB (T3) and 4) 1 hour after CPB (T4). APCI and PACI were analyzed by using the Bland-Altman analysis. RESULTS: Biases of APCI and PACI at T1, T2, T3 and T4 were 0.093 L/min/m2, -0.053 L/min/m2, 0.485 L/min/m2 and -0.09 L/min/m2, respectively. The limits of agreement (2 SD) at T1, T2, T3 and T4 were from -2.285 to 2.471 L/min/m2, -2.475 to 2.369 L/min/m2, -2.255 to 3.225 L/min/m2 and -2.609 to 2.423 L/min/m2, respectively. Bias of APCI and PACI during entire period (T1-T4) was 0.095 L/min/m2 and 2 SD was from -2.387 to 2.557 L/min/m2. However, mean error % (2 SD/mean) of APCI at T1, T2, T3, and T4 were greater than 30%. CONCLUSIONS: Our results were not able to show that APCI measured from radial artery is comparable to PACI for hemodynamic monitoring during cardiac surgery employing moderate hypothermic CPB. Considering the limitations of PACI as a gold standard of hemodynamic monitoring in a certain clinical circumstance, further investigation employing other monitoring method than PACI may be followed to get more definitive conclusion.
Anesthesia ; Arterial Pressure ; Bias (Epidemiology) ; Cardiopulmonary Bypass ; Catheters ; Hemodynamics ; Pulmonary Artery ; Radial Artery ; Thermodilution ; Thoracic Surgery

BACKGROUND: AVP (arginine vasopressin) shows unique hemodynamic characteristics, as a vasopressor. AVP has been tried in many cathecholamine refractory vasodilatory situations, and sometimes resulted in effective hemodynamic improvement. In this study, we hypothesized that low dose AVP infusion could recover the decreased SVR (systemic vascular resistance) induced by milrinone infusion with minimal effect on PVR (pulmonary vascular resistance). METHODS: Sixteen patients undergoing OPCAB participated in this study. After a loading dose milrinone was infused, low dose vasopressin infusion was started and titrated until the systemic blood pressure increased by 20%. During the study, hemodynamic factors including pulmonary capillary wedge pressure and cardiac output were measured using a continuous thermodilution technique with a Swan-Ganz catheter. RESULTS: Milrinone infusion reduced both SVR and PVR. And vasopression infusion increased SVR, but show relatively less effect on PVR. CONCLUSIONS: Low-dose vasopressin infusion could be used to recover the SVR decrease caused by milirinone infusion with little effect on PVR.
Blood Pressure ; Cardiac Output ; Catheters ; Hemodynamics* ; Humans ; Milrinone* ; Pulmonary Wedge Pressure ; Thermodilution ; Vasopressins*

Cardiac output measurement is so important that it is widely used in anesthesia and intensive care practice.However, the basic principles for the measurement of each device are not taught for clinicians.This review article describes considerable points for each device; 1) temperature sensors and integration problem for pulmonary artery catheter, 2) angle of ultrasonic probe and meaning of turbulent flow for transesophageal echocardiography, 3) angle of ultrasonic probe and meaning of pulsatile laminar flow for CarioQ, 4) end-tidal and arterial carbon dioxide concentration for Noninvasive cardiac output, 5) the concept of convolution for the arterial pulse wave and arterial resistance for Vigileo, and 6) effect size as a statistical viewpoint of comparison in device effectiveness.As a clinician we should not interpret the value of cardiac output as an absolute meaning, but do as a relative trend considering these theoretical errors.
Anesthesia ; Carbon Dioxide ; Cardiac Output ; Catheters ; Echocardiography, Transesophageal ; Critical Care ; Pulmonary Artery ; Thermodilution ; Ultrasonics

Permanent electrostimulation is the therapy of choice for syncope due to bradycardic rhythm disturbance. In maintaining optimal hemodynamic function, the role of atrial systole has been well recorgnized and the time relationship between atrial and ventricular systole have great relation with cardiac output. Assessment of optimal mode of cardiac pacing by nonivasive method is very important for the best hemodynamic effect. To evaluate the usefulness of systolic time interval for optimal pacing mode, we calculated systolic time interval by using ventricular pacing spike on electrocardiogram to aortic opening time/left ventricular ejection time by aortic pressure curve (invasive PEP/LVET) in various modes of cardiac pacing and measured cardiac output by thermodilution method simultaneously in 9 mongrel dogs. Basal pacing cycle length were 300 msec, and the atrioventricular (AV) and ventriculoatrial (VA) interval during AB & VA sequential pacing were set at 30 msec, 60 msec and 90 msec. The result were as follows: 1) The cardiac output at AV interval of 90 msec (1.65+/-0.23 L/min) is significantly higher than 30 msec (1.38+/-0.19 L/min) in AV sequential pacing. 2) The cardiac output in ventricular pacing is higher than VA sequential pacing, but no significant changes noted among VA interval 90 msec, 60 msec and 30 msec. 3) The invasive PEP/LVET at VA interval of 90 msec (0.85+/-0.17) is significantly lower than 60 msec (0.97+/-0.16) and 30 msec (1.01+/-0.16) in AV sequential pacing. 4) The invasive PEP/LVET among VA sequential pacing with 90 msec, 60 msec, 30 msec interval and ventricular pacing did not show any significant difference. 5) When AV interval changes from 90 msec to 30 msec during AV sequential pacing, cardiac output decreased and invasive PEP/LVET increased. 6) In VA sequential pacing, there were no changes of cardiac output and invasive PEP/LVET when VA interval changes from 90 msec to 30 msec. In conclusion, systolic time interval can be used for estimation of hemodynamic changes during AV sequential pacing considering our results and other authors' results of high correlation between invasive & noninvasive PEP/LVET.
Animals ; Arterial Pressure ; Cardiac Output ; Dogs ; Electrocardiography ; Hemodynamics ; Syncope ; Systole* ; Thermodilution

AIMTo introduce a new device and catheter to be determining cardiac output through cor sinistrum with thermodilution.

METHODSOwn control was introduced in eight dogs. A pulmonary thermodilution catheter was used through the cor dextrum of the dogs; The new-design catheter was used through artery, and there were two situs to fix:its ahead in left atrium and the ahead near to aortic root. Determine cardiac output (CO) under four circumstances: controlled respiration, apnoea, in controlled hypotension, after controlled hypotension.

RESULTSThere was no significant difference among the parameters (CO and cardiac index) of all circumstances. The CO determined by the pulmonary thermodilution catheter and those by the new-design catheter in two situs were positive correlation, and the gamma were 0.986, 0.989; likewise, the cardiac index (CI) was positive correlation, and the gamma were 0.983, 0.985. The CO and CI by the new-design catheter between two situs were positive, and the gamma were 0.992, 0.988.

CONCLUSIONThe parameters by the new-design catheter and those by the pulmonary thermodilution catheter were concordant. In comparison with the pulmonary thermodilution catheter, the new-design catheter had simple device and could be easily operated.

BACKGROUND: Esophageal doppler is discribed as a non-invasive alternative to cardiac output (CO) estimation by thermodilution, the current bedside "gold standard". This study was designed to evaluate the accuracy of CO estimations performed by esophageal doppler (EDCO), compared to those obtained using a continuous CO pulmonary flotation catheter (TDCO). METHODS: In 16 patients undergoing off-pump coronary artery bypass surgery, CO was measured simultaneously by the esophageal doppler and the thermodilution method, after induction (A), after sternotomy (B), after coronary revascularization (C), and after sternal closure (D). Agreement between the TDCO and EDCO estimations was assessed by analyzing their mean differences and the distribution of these differences. Relative CO changes (percentages of the previous value) was analyzed by the same method. RESULTS: Both absolute CO values and relative CO changes by esophageal doppler showed a considerable scatter compared to those obtained using the thermodilution method. The bias (EDCO-TDCO) between the two mehtods was -0.8 +/- 2.7 L/min for A, -0.9 +/- 2.5 L/min for B, -0.9 +/- 3.6 L/min for C, and -0.6 +/- 2.7 (mean +/- 2 SD) L/min for D. On analyzing changes in CO, no significant method bias was found but 2 SD of the bias were +/- 74% for A to B, +/- 100% for B to C, and +/- 83% for C to D. CONCLUSIONS: These results suggest that CO estimations by esophageal doppler cannot replace estimations by the thermodilution method in patients undergoing off-pump coronary artery bypass graft surgery.
Bias (Epidemiology) ; Cardiac Output* ; Catheters ; Coronary Artery Bypass, Off-Pump* ; Humans ; Sternotomy ; Thermodilution* ; Transplants