The Stewart–Hamilton Equations and The Indicator Dilution Method

1978 ◽  
Vol 34 (4) ◽  
pp. 666-675 ◽  
Author(s):  
M. Profant ◽  
K. Vyska ◽  
U. Eckhardt
Keyword(s):  
Indicator Dilution ◽  
Dilution Method ◽  
Hamilton Equations

Measurement of femoral artery bloodflow using the indicator-dilution method

1962 ◽  
Vol 2 (6) ◽  
pp. 386-396 ◽  
Author(s):  
John T. Hobbs ◽  
Giorgio Agrifoglio ◽  
Edward A. Edwards
Keyword(s):  
Femoral Artery ◽  
Indicator Dilution ◽  
Dilution Method

Determination of central blood volume. Comparison of Stewart-Hamilton method with direct measurements in dogs

1959 ◽  
Vol 196 (3) ◽  
pp. 499-501 ◽  
Author(s):  
Robert C. Schlant ◽  
Paul Novack ◽  
William L. Kraus ◽  
Charles B. Moore ◽  
Florence W. Haynes ◽  
...  
Keyword(s):  
Cardiac Output ◽  
Blood Volume ◽  
Transit Time ◽  
Mean Transit Time ◽  
Total Radioactivity ◽  
Indicator Dilution ◽  
Dilution Method ◽  
Central Blood Volume ◽  
Volume Comparison ◽  
Direct Measurements

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.

Changes in cerebral blood flow and oxygen metabolism during moderate hypothermia in patients with severe middle cerebral artery infarction

2000 ◽  
Vol 8 (5) ◽  
pp. 1-4 ◽  
Author(s):  
Emanuela Keller ◽  
Thorsten Steiner ◽  
Javier Fandino ◽  
Stefan Schwab ◽  
Werner Hacke
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Ischemic Stroke ◽  
Middle Cerebral Artery ◽  
Cerebral Artery ◽  
Mild Hypothermia ◽  
Indicator Dilution ◽  
Dilution Method ◽  
Moderate Hypothermia ◽  
Double Indicator Dilution

Object Moderate hypothermia has been reported to be effective in the treatment of postischemic brain edema. The effect of hypothermia on cerebral hemodynamics is a matter of controversial discussion in literature. Clinical studies have yet to be performed in patients with ischemic stroke after induction of hypothermia. Methods Measurements during mild hypothermia (33–34°C) were made in six patients with severe ischemic stroke involving the middle cerebral artery territory. Hypothermia was induced as soon as possible and maintained for 48 to 72 hours. Cerebral blood flow (CBF) and cerebral metabolic rate of oxygen (CMRO2) were estimated by a new double-indicator dilution method. Measurements of CBF were made during normothermia, immediately after induction of hypothermia, at the end of hypothermia, and after rewarming. A total of 19 measurements of CBF and jugular bulb O2 saturation were made. Immediately after induction of hypothermia, CBF decreased in all patients. During late hypothermia, CBF improved in patients who survived but remained diminished in the two patients who died. Reduced CMRO2 levels were observed during all phases of hypothermia in all but one case. Conclusions Preliminary oberservations indicate that moderate hypothermia seems to reduce CMRO2 Immediately after induction of hypothermia, CBF may decrease in all patients. During late hypothermia CBF seems to recover in patients with good outcome but remains diminished in patients who die. Serial bedside CBF measurements with the new double-indicator dilution technique may be useful to describe cerebral hemodynamic characteristics in patients with severe ischemic stroke during hypothermia.

Detection of early central circulatory transits in patients with cirrhosis by gamma variate fit of indicator dilution profiles

2005 ◽  
Vol 288 (4) ◽  
pp. G677-G684 ◽  
Author(s):  
Jens H. Henriksen ◽  
Søren Møller ◽  
Stefan Fuglsang ◽  
Flemming Bendtsen
Keyword(s):  
Cardiac Output ◽  
Blood Volume ◽  
Indicator Dilution ◽  
Arterial Oxygen ◽  
Dilution Method ◽  
Gamma Variate ◽  
Arterial Blood ◽  
Flow Circulation ◽  
Cirrhotic Patients

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.

An Indicator-Dilution Method for Studying Intestinal Hemodynamics in the Cat

1973 ◽  
Vol 87 (4) ◽  
pp. 433-447 ◽  
Author(s):  
Björn Blber ◽  
Ove Lundgren ◽  
Lars Stage ◽  
Joar Svanvik
Keyword(s):  
Indicator Dilution ◽  
Dilution Method
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