title: Evaluation of monoexponential extrapolation of transpulmonary thermal-dye kinetics by use of a new model-free deconvolution algorithm.
abstract: 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.
authors.affiliation: Zentrum Physiologie und Pathophysiologie, Universität Göttingen, Federal Republic of Germany.
authors.forename: J C
authors.initials: JC
authors.lastname: Böck
authors.forename: P
authors.initials: P
authors.lastname: Deuflhard
authors.forename: A
authors.initials: A
authors.lastname: Hoeft
authors.forename: H
authors.initials: H
authors.lastname: Korb
authors.forename: J
authors.initials: J
authors.lastname: Steinmann
authors.forename: H G
authors.initials: HG
authors.lastname: Wolpers
authors.forename: G
authors.initials: G
authors.lastname: Hellige
mesh_terms: 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
chemical_list: D009829:Oleic Acids; D019301:Oleic Acid; D007208:Indocyanine Green