Clinical evaluation of the FloTrac/Vigileo system and two established methods for continuous cardiac output monitoring in patients undergoing cardiac surgery

Introduction

A new arterial pressure waveform analysis device, which does not need external calibration (FloTrac/Vigileo; Edwards Lifesciences, Irvine, CA, USA), became recently available for cardiac output (CO) measurement. However, only limited validation data for this technique are so far available [1, 2].

Objective

The aim of this study was to compare cardiac output assessed by the FloTrac/Vigileo system (FCO), the PiCCOplus system (PCO) [1] (Pulsion Medical Systems; Munich, Germany) and continuous cardiac output (CCO) monitoring using a pulmonary artery catheter (Vigilance; Edwards Lifesciences) with intermittent pulmonary artery thermodilution (ICO) in cardiac surgery patients.

Methods

With ethics committee approval and written patient informed consent, patients undergoing elective cardiac surgery were studied. The CCO, FCO and PCO were recorded in the perioperative period after induction of anaesthesia (= study initiation) and 1, 4, 8, 12 and 24 hours post initiation. At each measurement point the ICO was assessed as mean of three repeated bolus injections. Statistical analysis was done using Bland–Altman analysis of absolute CO values and of percentage changes (δ) between consecutive CO measurements (= trend analysis).

Results

One hundred and eighty-five matched sets of data were available for statistical analysis from 31 patients (ASA III, male/female ratio = 26/5, mean ± SD age = 66.58 ± 0.53 years (range: 45–84 years), mean ± SD body mass index = 28.2 ± 5.3 kg/m² (range: 19.5–48.0 kg/m²)). CO values during the observation time ranged from 2.4 to 9.3 l/min. Bland–Altman analysis revealed a mean bias ± 2SD (limits of agreement) of 0.20 ± 2.3 l/min for FCO-ICO, 0.3 ± 2.7 l/min for PCO-ICO and 0.3 ± 2.5 l/min for CCO-ICO. Mean bias ± 2SD was -3.6 ± 59.2% for δ FCO-δ ICO, -1.6 ± 67.1% for δ PCO-δ ICO and 2.5 ± 58.8% for δ ICO-δ CCO.

Conclusion

These results indicate that the FloTrac/Vigileo system is a reliable alternative to PiCCO and the pulmonary artery catheter for CO measurement in cardiac surgery patients.