Evaluation of monoexponential extrapolation of transpulmonary thermal-dye kinetics by use of a new model-free deconvolution algorithm.
This study evaluates the routine mathematic approach (monoexponential extrapolation) for analysis of transpulmonary thermal-dye dilution curves and estimates the effects of systemic-indicator recirculation by use of a deconvolution technique. Fifteen dogs anesthetized with N2O-piritramid were studied before and after induction of pulmonary edema by oleic acid. After introduction of central venous indicator (10 ml of a mixture of cold blood and indocyanine green dye), dilution data were recorded from the pulmonary artery and the ascending aorta. The conclusions were: (1) monoexponential extrapolation yields reasonably good estimates of the mean transit times of dye; (2) mean transit times of heat are usually overestimated by monoexponential extrapolation; (3) extravascular lung thermal volume assessed by monoexponential extrapolation is overestimated by 2.03 ml/kg of body mass under baseline conditions; and (4) the prepulmonary volume of distribution of heat exceeds that of dye by 1.4 ml/kg of body mass, thus increasing the overestimation of pulmonary extravascular heat-accessible space by the conventional technique.
Böck
J C
JC
Zentrum Physiologie und Pathophysiologie, Universität Göttingen, Federal Republic of Germany.
Deuflhard
P
P
Hoeft
A
A
Korb
H
H
Steinmann
J
J
Wolpers
H G
HG
Hellige
G
G
D000465:Algorithms; D000818:Animals; D002302:Cardiac Output; D004285:Dogs; D004395:Dye Dilution Technique; D005110:Extracellular Space / Q000378:metabolism*; D005260:Female; D007208:Indocyanine Green; D008168:Lung / Q000378:metabolism*; D008297:Male; D008954:Models, Biological; D019301:Oleic Acid; D009829:Oleic Acids; D011654:Pulmonary Edema / Q000139:chemically induced / Q000503:physiopathology; D013815:Thermodilution
D009829:Oleic Acids; D019301:Oleic Acid; D007208:Indocyanine Green