title: Cardiac output measurement by pulse dye densitometry in cardiac surgery.
abstract: Summary The aim of this study was to compare the accuracy of pulse dye densitometry with that of bolus thermodilution cardiac output measurement in patients before and after elective coronary artery bypass grafting. Twenty-eight patients were studied. Agreement between mean thermodilution and pulse dye densitometry cardiac output values was assessed by Bland-Altman analysis. Preoperative median [range] cardiac output was 3.87 [2.37-6.0] l.min(-1) by thermodilution, and 3.11 [1.7-5.45] l.min(-1) by pulse dye densitometry using indocyanine green 5 mg. Pulse dye densitometry underestimated cardiac output (mean bias - 0.42 l.min(-1)); the limits of agreement were +/- 1.91 l.min(-1), and mean error was 50.3%, indicating low precision. Preoperative median [range] cardiac output was 3.85 [2.2-6.0] l.min(-1) for bolus thermodilution cardiac output and 4.2 [2.0-7.2] l.min(-1) for pulse dye densitometry using indocyanine green 20 mg. Mean bias was + 0.566 l.min(-1), the limits of agreement were +/- 2.51 l.min(-1) and mean error was 60.9%. Postoperative cardiac output data were not analysed because pulse dye densitometry signals were low or absent in > 50% of the patients. We conclude that pulse dye densitometry using indocyanine green 5 mg or 20 mg is inaccurate in anaesthetised patients before coronary artery bypass surgery and cannot be used after surgery because of a high incidence of low pulse dye densitometry signal amplitudes.
authors.affiliation: Division of Cardiovascular Anaesthesia, University Hospital of Zürich, Rämistrasse 100, 8091 Zürich, Switzerland. werner.Baulig@usz.ch
authors.forename: W
authors.initials: W
authors.lastname: Baulig
authors.forename: E O
authors.initials: EO
authors.lastname: Bernhard
authors.forename: D
authors.initials: D
authors.lastname: Bettex
authors.forename: D
authors.initials: D
authors.lastname: Schmidlin
authors.forename: E R
authors.initials: ER
authors.lastname: Schmid
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000886:Anthropometry; D002302:Cardiac Output; D003287:Contrast Media; D001026:Coronary Artery Bypass; D003720:Densitometry; D005260:Female; D006801:Humans; D007208:Indocyanine Green; D008297:Male; D008875:Middle Aged; D019990:Perioperative Care / Q000379:methods; D015203:Reproducibility of Results; D013815:Thermodilution
chemical_list: D003287:Contrast Media; D007208:Indocyanine Green