The accuracy of the Vigileo/FloTrac continuous cardiac output monitor.

OBJECTIVE

The Vigileo/FloTrac system (software version 1.01; Edwards Lifesciences, Irvine, CA) determines cardiac output, without calibration, by analysis of the arterial pulse wave. To assess the accuracy of the Vigileo/FloTrac system, it was compared with the pulmonary artery catheter bolus thermodilution method as the current standard method. The study design was prospective and observer blinded.

SETTING

A single university hospital.

PARTICIPANTS

Thirty elective coronary artery bypass graft surgery patients. No special interventions were done to the participants.

MEASUREMENTS AND MAIN RESULTS

After approval by the ethics committee and with written informed consent, synchronized measurements using both methods were made at 7 predefined time points, intraoperatively and postoperatively, producing 192 data pairs for evaluation. The statistical evaluation was performed by using the Bland-Altman method of analysis. In addition, a +/-20% and +/-30% deviation from the pulmonary artery catheter were evaluated (20% criteria and 30% criteria). In total, 46% of measurements did not fulfill the 20% criteria; 26% were outside the 30% limits. The Bland-Altman analysis for all time points showed that 95% of all differences between both methods were within a range between -2.2 and +3.1 L/min. Regression analysis revealed low correlation values at all time points.

CONCLUSION

The described deviation from the standard must be regarded according to the user's needs. Considering the 30% limits of agreement, the Vigileo system (version 1.01) seems sufficiently accurate; applying the 20% criteria, it is not.