Arterial pulse waveform analysis has been proposed for cardiac output (CO) determination and monitoring without calibration or thermodilution (FloTrac™/Vigileo™; Edwards Lifesciences, Irvine, CA, USA). The accuracy and clinical applicability of this technology has not been fully evaluated. We designed this prospective study to compare the accuracy of the FloTrac™ system (COFT) vs. pulmonary artery catheter standard bolus thermodilution (COPAC) in patients undergoing coronary artery bypass grafting.Methods:
We studied 11 patients referred for coronary artery bypass grafting. COFT and COPAC were determined at six time points in the operating room including before and 5 min after volume expansion (500 mL 6% hetastarch). Measurements were performed on arrival in the intensive care unit and every 4 h afterwards. Bland-Altman analysis was used to assess the agreement between COFT and COPAC.Results:
COPAC ranged from 2.0 to 7.6 L min−1 and COFT ranged from 1.9 to 8.2 L min−1. There was a significant relationship between COPAC and COFT (r = 0.662; P < 0.001). Agreement between COPAC and COFT was −0.26 ± 0.87 L min−1. Volume expansion induced a significant increase in both COPAC and COFT (from 3.4 ± 0.8 to 4.4 ± 1.0 L min−1; P < 0.001 and from 3.9 ± 1.2 to 5.0 ± 1.1 L min−1; P < 0.001, respectively) and there was a significant relationship between percent change in COPAC and COFT following volume expansion (r = 0.722; P = 0.01).Conclusion:
We found clinically acceptable agreement between COFT and COPAC in this setting. This new device has potential clinical applications.