Reliability of continuous pulse contour cardiac output measurement

Introduction

To evaluate the reliability of continuous cardiac output monitoring using pulse-contour analysis in critically ill patients.

Methods

We retrospectively analyzed the agreement between transpulmonary thermodilution cardiac output (TPCO) and pulse contour cardiac output (PCCO) measured before recalibration of the TPCO from 34 patients with hemodynamic instability. Logistic regression analysis was used to identify the independent factors for the disagreement between TPCO and PCCO, defined as a relative change >15%.

Results

We obtained 261 pairs of measurements. The relative change in systemic vascular resistance calculated with TPCO (ΔSVR-TPCO) of over 20% was the only independent factor for disagreement, while the relative change in systemic vascular resistance calculated with PCCO (ΔSVR-PCCO) and the time interval between calibrations had no predictive value of the reliability of PCCO. See Figure 1.

Figure 1

Conclusion

ΔSVR-TPCO > 20% was associated with unreliability of PCCO measurement. Reliability of PCCO could not be predicted by continuous monitoring parameters, such as ΔSVR-PCCO.