Prediction of fluid responsiveness by FloTrac™ and PiCCOplus™ in cardiac surgery patients

Introduction

The aim of this study was to compare the prediction of fluid responsiveness [1] using the stroke volume variation (SVV) determined by FloTrac™ (SVV-FloTrac; Edwards Lifesciences, USA) and PiCCOplus™ (SVV-PiCCO; Pulsion Medical Systems, Germany).

Methods

With ethics committee approval, the SVV-FloTrac, SVV-PiCCO, pulse pressure variation (PPV), global end-diastolic volume (GEDV) and stroke volume (SV) were measured before and after a volume shift induced by body positioning (30° head-up to 30° head-down) in 40 patients after cardiac surgery. A t test, Bland–Altman analysis, Pearson correlation and area under the receiver operating curves (AUC) were calculated. P < 0.05 was considered significant.

Results

Body positioning resulted in a significant SV and GEDV increase, while SVV-FloTrac, SVV-PiCCO and PPV significantly decreased. Comparably strong correlations between SVV-FloTrac/SVV-PiCCO and ΔSV were observed (Table 1). The best AUC was found for SVV-FloTrac (threshold value: 12.1%) and SVV-PiCCO (threshold value: 9.6%). Mean bias ± 2 SD (SVV-FloTrac – SVV-PiCCO) was -2.5 ± 6.2%, and the correlation coefficient (r²) was 0.72 (P < 0.01).

Table 1 AUC predicting ΔSV > 25% and Pearson correlation of baseline indices versus ΔSV

Conclusion

SVV-FloTrac and SVV-PiCCO showed a comparable performance in predicting fluid responsiveness. When compared with SVV-PiCCO, a lower threshold value for SVV-FloTrac has to be considered.