System modeling and identification in indicator dilution method for assessment of Ejection Fraction and Pulmonary Blood Volume

2012 ◽  
Vol 7 (6) ◽  
pp. 640-648 ◽  
Author(s):  
H.N. Bharath ◽  
K.M.M. Prabhu ◽  
H.H.M. Korsten ◽  
M. Mischi
1959 ◽  
Vol 196 (3) ◽  
pp. 499-501 ◽  
Author(s):  
Robert C. Schlant ◽  
Paul Novack ◽  
William L. Kraus ◽  
Charles B. Moore ◽  
Florence W. Haynes ◽  
...  

Central blood volume (cardiac output times mean transit time) from right atrium to ascending aorta was determined by the indicator-dilution method in 22 open-chested dogs which had previously had their red blood cells tagged with Cr51. The actual amount of blood in the heart and lungs was calculated from the total radioactivity in the blended homogenate of these organs. The two measurements of central blood volume correlated well ( r = +.88), the indicator-dilution volumes averaging 12% greater. The discrepancy between measurements is probably related to the pulmonary circuit having a lower hematocrit than the large vessels. The results substantiate the use of the Stewart-Hamilton formula (cardiac output times mean transit time) to measure central blood volume.


1962 ◽  
Vol 202 (5) ◽  
pp. 957-960 ◽  
Author(s):  
Charles J. McGaff ◽  
William R. Milnor

Changes in pulmonary blood volume produced by continuous intravenous infusion of serotonin (5-hydroxytryptamine) were measured in 16 experiments on ten dogs. Pulmonary mean transit time was measured by the dye dilution method, using consecutive injections into pulmonary artery and left atrium; pulmonary blood volume was calculated by multiplying this mean transit time by the cardiac output. Serotonin lowered pulmonary blood volume by an average of 2.9 ml/kg, or 26% of the control value ( P <0.001). Pulmonary vascular resistance increased 94 ru (resistance units) kg, and systemic vascular resistance fell 294 ru kg, effects similar to those reported by other investigators. The magnitude of the decrease in pulmonary blood volume indicates that a relatively large part of the pulmonary vascular bed is constricted by serotonin, and provides an example of shifting of blood from pulmonic to systemic circuits by reciprocal changes in the distensibility of these beds.


2005 ◽  
Vol 288 (4) ◽  
pp. G677-G684 ◽  
Author(s):  
Jens H. Henriksen ◽  
Søren Møller ◽  
Stefan Fuglsang ◽  
Flemming Bendtsen

Patients with cirrhosis have hyperdynamic circulation with abnormally distributed blood volume and widespread arteriovenous communications. We aimed to detect possible very early (i.e., before 4 s) and early (i.e., after 4 s) central circulatory transits and their potential influence on determination of central and arterial blood volume (CBV). Thirty-six cirrhotic patients and nineteen controls without liver disease undergoing hemodynamic catheterization were given central bolus injections of albumin with different labels. Exponential and gamma variate fits were applied to the indicator dilution curves, and the relations between flow, circulation times, and volumes were established according to kinetic principles. No significant very early central circulatory transits were identified. In contrast, early (i.e., 4 s to maximal) transits corresponding to a mean of 5.1% (vs. 0.8% in controls; P < 0.005) of cardiac output (equivalent to 0.36 vs. 0.05 l/min; P < 0.01) were found in cirrhotic patients. These early transits averaged 7.7 vs. 12.7 and 17.2 s of ordinary central transits of cirrhotic patients and controls, respectively ( P < 0.001). Early transits were directly correlated to the alveolar-arterial oxygen difference in the cirrhotic patients ( r = 0.46, P < 0.01) but not in controls ( r = 0.04; not significant). There was good agreement between the CBV determined by the conventional indicator dilution method and that determined by separation of early and ordinary transits by the gamma variate fit method (1.51 vs. 1.53 liter; not significant). In conclusion, no very early central circulatory transits were identified in cirrhotic patients. A significant part of the cardiac output undergoes an early transit, probably through pulmonary shunts or areas with low ventilation-perfusion ratios in cirrhotic patients. Composite determination of CBV by the gamma variate fit method is in close agreement with established kinetic methods. The study provides further evidence of abnormal central circulation in cirrhosis.


1967 ◽  
Vol 73 (5) ◽  
pp. 665-668 ◽  
Author(s):  
Gilberto Sanchez ◽  
Antonio C. Quiroz ◽  
George E. Burch ◽  
Nicholas P. DePasquale

1959 ◽  
Vol 197 (1) ◽  
pp. 187-189
Author(s):  
Alceo Barrios ◽  
Colin Fell ◽  
W. F. Hamilton

Pulmonary blood flow, pressures, volume and vascular resistance were measured when the lungs occupied an expiratory position in the closed chest and when they were collapsed by introducing air into the thorax. Circulation and innervation were intact. Variations due to respiratory movements or asphyxia were ruled out. Mongrel dogs were used, anesthetized with morphine and sodium pentobarbital. Pressures were measured from pulmonary artery, left atrium, aortic arch and intrapleural space. Pulmonary flow was evaluated utilizing the dye dilution method and the pulse contour method. Vascular volume was estimated by the product of mean circulation time and flow. When the lungs were collapsed there was an immediate elevation of intraluminal left atrial pressure but not a comparable rise in pulmonary arterial pressure. However, the direct records of arteriovenous pressure drop suggest that there was a delayed rise in pulmonary artery pressure. Flow, aortic pressure, heart rate and pulmonary vascular resistance showed no consistent changes. In 8 of 11 cases the pulmonary blood volume decreased when the lungs were collapsed.


1959 ◽  
Vol 14 (4) ◽  
pp. 531-534 ◽  
Author(s):  
Arnold M. Weissler ◽  
Burley H. McCraw ◽  
James V. Warren

A semiquantitative technique for assaying shifts in intrapulmonary blood volume is described. The method consists of the external monitoring of radioactivity over the anterior thorax after the intravenous administration of radioactive iodinated albumin utilizing a sensitive scintillation counter with a focusing collimator attachment. While this method does not yield the quantitative data of the indicator dilution and body plethysmographic techniques, it offers the advantage of confining observations to the intrapulmonary rather than the intrathoracic blood volume. Employing this technique, the effects of the upright posture, peripheral venous pooling and the Valsalva maneuver have been studied. A fall in estimated pulmonary blood volume was noted with each procedure, averaging 28%, 9% and 11%, respectively, below control levels. Submitted on January 16, 1959


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