title: Intra-operative evaluation of a continuous versus intermittent bolus thermodilution technique of cardiac output measurement in cardiac surgical patients.
abstract: The purpose of this study was to analyse the clinical agreement between cardiac output measurements, obtained using a newly available continuous thermodilution technique, and the conventional intermittent bolus technique. Twenty-four cardiac surgical patients were intra-operatively monitored using both techniques. Additionally, two different averaging modes for the continuous thermodilution technique, either the previous 6 min (group 1) or 3 min (group 2) were compared. The mean difference between the continuous thermodilution technique and the intermittent bolus technique (bias), were calculated at eight selected time points. These ranged from -0.09 to 0.42 litres min-1 in group 1 and from -0.02 to 0.18 litres min-1 in group 2. There were significant differences at any time point between the groups. The relative error between continuous thermodilution and intermittent bolus techniques was < 15% for the majority of measurements and was significantly higher in group 1 compared with group 2 just prior to cardiopulmonary bypass. Thus, the continuous thermodilution technique produced a clinically acceptable level of accuracy compared with the intermittent bolus technique measurements, especially when using an averaging mode for the previous 3 min.
authors.affiliation: Department of Anaesthesia, University Hospital, Regensburg, Germany.
authors.forename: G
authors.initials: G
authors.lastname: Rödig
authors.forename: C
authors.initials: C
authors.lastname: Keyl
authors.forename: A
authors.initials: A
authors.lastname: Liebold
authors.forename: J
authors.initials: J
authors.lastname: Hobbhahn
mesh_terms: D000368:Aged; D000768:Anesthesia, General; D002138:Calibration; D002302:Cardiac Output; D006348:Cardiac Surgical Procedures; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000379:methods*; D013815:Thermodilution