No abstract available.
Cardiac Output* ; Ultrasonography*

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*

The cardiac output and hemodynamic indices were measured by the bioimpedance method using NCCOM3 in 38 selected spinal anesthetic cases with 0.5% bupivacain. The authors observed MAP, HR, PFI, EDI, CI and SI changes before-and during spinal anesthesia. The results were as follows: The mean values for MAP before, 10 minutes and 30 minutes after spinal anesthesia were observed to be 96.18+/-14.25 and 9.45+/-14.89 mmHg. These values during spinal anesthesia were significantly decreased compared with the value before spinal anesthesia(P<0.01). The mean values for HR before, and 30 minutes after spinal anesthesia were observed to be 71.34+/-17.25 and 72.39+/-19,01 beat/min. The value during spinal anesthesia was significantly decreased compared with the value before spinal anesthesia(P<0.01). The mean value for PFI before and during spinal anesthesia were observed to be 306.55+/-75.63 and 285.47+/-73.60 1/sec/m2 . The value duing spinal anesthesia was insignificantly decreased compared with the value before spinal anesthesia.(P<0.05). The changes of mean values of EF, EDI and SI were insignificant statistically. The mean values for CI before and 30 minutes after spinal anesthesia were observed to be 3.49+/-1.02 and 3.11+/-0.86(1/min/m2) The value during spinal anesthesia was significantly decreased compared with the value before spinal Anesthesia(P<0.01)
Anesthesia, Spinal* ; Cardiac Output ; Hemodynamics*

No abstract available.
Cardiac Output* ; Ductus Arteriosus* ; Humans ; Infant, Newborn*

This cardiac output detector uses AT89C52 as the core MCU, carries the pulse signal sampling from pulse sensor into the SCM after A/D conversion, and then figures out the cardiac output value and displays it on the LED. Software analysis works out the cardiac output value through five-point difference threshold for feature location of the pulse graph method theory. Experiment results show that the normal measured cardiac output is 5.411 L/min, the standard deviation of 0.873, while the catheter method as the gold standard of the mean 5.51 L/min, the standard deviation of 1.09. This system can meet the testing requirements of normal cardiac output. It is a non-invasive, convenient and new cardiac output measurement instrument with continuous testing, easy operation and low cost.
Cardiac Output ; Monitoring, Physiologic ; instrumentation ; methods ; Pulse

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.

Cardiovascular disease has become a serious disease that threatens the health of human beings, cardiac output is an important indicator of cardiovascular function, monitoring cardiac output and related hemodynamic parameters have significant clinical value. This article summarizes the development history, principle, method, advantages and disadvantages of various monitoring technologies from three aspects:invasive, minimally invasive and noninvasive, the development and application of cardiac output monitoring technology are prospected.
Cardiac Output ; Hemodynamics ; Humans ; Monitoring, Physiologic ; instrumentation

BACKGROUND: The required dose of anesthetics is generally smaller in patients with low cardiac output (CO). A high CO decreases the blood concentration of anesthetics during induction and maintenance of anesthesia. However, a high CO may also shorten the delivery time of anesthetics to the effect site, e.g. the brain. We assessed the time required for induction of anesthesia with propofol administered by target-controlled infusion (TCI), and investigated factors that modify the pharmacodynamics of propofol. METHODS: After measuring CO and blood volume (BV) by dye densitometry, propofol was infused using TCI to simulate a plasma concentration of 3 microg/ml. After infusion, the time taken to achieve bispectral index (BIS) values of 80 and 60 was determined. Age, sex, lean body mass (LBM), and cardiovascular parameters were analyzed as independent variables. The dependent variables were the time taken to achieve each BIS value and the plasma concentration of propofol (Cp) 10 min after the commencement of infusion. RESULTS: Multiple regression analysis revealed that a high CO significantly reduced the time taken to reach the first end point (P = 0.020, R2 = 0.076). Age and LBM significantly prolonged the time taken to reach the second end point (P = 0.001). Cp was negatively correlated with BV (P = 0.020, R2 = 0.073). CONCLUSIONS: Cardiac output was a statistically significant factor for predicting the time required for induction of anesthesia in the initial phase, whereas, age and LBM were significant variables in the late phase. The pharmacodynamics of propofol was intricately altered by CO, age, and LBM.
Anesthesia ; Anesthetics ; Blood Volume ; Brain ; Cardiac Output ; Cardiac Output, Low ; Consciousness Monitors ; Densitometry ; Humans ; Plasma ; Propofol

Capnogram, monitoring of end-tidal CO2, has been a popular tool for assessment of ventilatory status during modern anesthesia. A normal curve on capnogram suggests normal CO2 production, adequate circulation, and adequate ventilation. Level of end-tidal CO2. is different from that of arterial CO2 even in normal individual. The difference is originated from alveolar dead space gas which dilute concentration of CO2 from normal alveoli. In clinical situation, the major factor which determines alveolar dead space is low pulmonary blood flow. Decrease of alveolar capillary perfusion from low cardiac output is the most important cause of low measure of end-tidal CO and large difference between arterial CO2 and end-tidal CO2 concentration in perioperative period. To understand the effect of cardiac output on end-tidal CO2 tension and the difference between arterial CO2 tension and end-tidal CO2 tension, We measured cardiac output before and dutiag administration of nitroglycerine and sodium nitropruside for relieve of myocardial load before aortic clamping in 30 male patients undergoing aortic recontructive surgery under endotracheal anesthesia for repair of infrarenal aortic obstruction. We also measured arterial CO2 tension, and end-tidal CO2 tension at the time of 10% decrease(phasel), 15% decrease(phase2)and 20% decrease(phase3) of cardiac output respectively. Measured values were statistically analyzed to evaluate correlation between cardiac output and end-tidal CO2 tension. The results are as follows: 1) Decreases of cardiac output brought about significant decrease in end-tidal CO2 in all phases compared to control value(p<0,05). 2) Decreases of cardiac output brought about significant increase in the difference between arterial- end-tidal CO2. tension in all phases compared to control value(p<0.05). 3) Changes in cardiac ourput correlated with changes in end-tidal CO2 tension significantly(p=0.0001, r=0.61, slope=2.01). 4) Changes in cardiac ourput correlated with changes in differences between arterial-end-tidal CO2 tension significantly(p=0.0001, r=-0.59, slope=-1.63). In conclusion we suggest that measurement of end-tidal CO2 tension, especially difference between arterial and end-tidal CO2 tension, may be a useful indicator for detection of cardiac output change during operation.
Anesthesia ; Capillaries ; Cardiac Output* ; Cardiac Output, Low ; Constriction ; Humans ; Male ; Nitroglycerin ; Perfusion ; Perioperative Period ; Sodium ; Ventilation

Systemic hypotension has been traditionally used to facilitate deployment of thoracic stent grafts. Decreasing blood pressure with vasodilating agents further increases cardiac output and, consequently, the cardiac output-mediated windsock effect during deployment. Use of rapid ventricular pacing reduces the windsock effect during stent graft deployment and allows the graft to appose to the aortic wall under zero cardiac output, thus minimizing aortic wall shear stress. In this case we report the use of transvenous rapid ventricular pacing, a safe and reproducible technique to allow precise deployment of a Valiant Captivia stent graft in the distal thoracic arch for a saccular thoracic aneurysm.
Aneurysm ; Aorta, Thoracic ; Blood Pressure ; Cardiac Output ; Hypotension ; Stents ; Transplants