Measurement of Cardiac Output and Central Volume by a Modified Decholin Test of Circulation Time

Abstract

A technic is described for determining mean circulation time, cardiac output, and central blood volume by use of graded dosages of sodium dehydrocholate (Decholin) administered into a peripheral vein. The indicator-dilution curves derived by the technic were compared with radiopotassium-dilution curves These concepts were tested experimentally by (1) determination indirectly of the blood concentrations of Decholin associated with the appearance and disappearance of the bitter taste, (2) determination of these times of onset and offset of taste following injections of 3 graded doses of Decholin, (3) construction of Decholin-dilution curves from the data on circulation times and blood concentrations at taste threshold, and finally (4) comparison of the results obtained from these curves with results obtained from radiopotassium-dilution studies carried out simultaneously. Comparisons of curve contour, cardiac output, central blood volume, and mean circulation time were made in 12 patients with and without cardiovascular disease. The correlation between the isotope and Decholin results was surprisingly good and indicates that the Decholin method is capable of providing more information than has been obtained in the past.

Local temperature control improves the accuracy of cardiac output estimation using lung‐to‐finger circulation time after breath holding

“…We hypothesized that we would be able to extend the method for the measurement of LFCT in awake patients if a patient can hold breath for a sufficient time to decrease the blood oxygen level adequately below the measurable level. Although there are several methods for the measurement of blood circulation time, they require the injection of some drugs (Conn et al., 1957) or inhalation of gas (Gubner et al., 1939), and each method needs a special device, thus making them unsuitable for daily practice. Hence, we planned to develop a new device that can detect LFCT by measuring the time from the restart of breathing after a certain duration of breath holding to the point at which the saturation of peripheral oxygen (SpO 2 ) shows the minimum value and thereafter begins to increase again.…”

Validity of Blood Volume Determinations in Hemorrhagic Shock in Rats

“…For normal conditions it may be assumed that the indicator is mixed completely after this time [19,23]. Under pathological conditions, however, the circulation time varies [7,8,22]. Therefore, a fixed mixing time of 10 min cannot be accepted.…”

“…Since blood volume computers [1,8,36] are reliable only under the conditions of an unchanged disappearance rate and the presumption that blood samples are taken only after complete distribution of the indica tor, exact knowledge of the equilibration pattern is essential for the use of such methods. Especially in pathological conditions, such as low flow…”