Uncalibrated radial and femoral arterial pressure waveform analysis for continuous cardiac output measurement: an evaluation in cardiac surgery patients.

OBJECTIVES: Arterial pressure waveform analysis is a less invasive alternative to the pulmonary artery catheter for continuous cardiac output (CO) measurement. Uncalibrated and calibrated systems are actually available (ie, the FloTrac/Vigileo system [Edwards Lifesciences, Irvine, CA] and the PiCCOplus system [Pulsion Medical Systems, Munich, Germany]). According to the FloTrac/Vigileo manufacturer, reliable measurements can be performed using any existing arterial catheter. The aim of this study was to evaluate CO determined by the FloTrac/Vigileo system using a radial (FCO(radial)) and femoral arterial catheter (FCO(femoral)) as well as the PiCCOplus system (PCO). Intermittent pulmonary artery thermodilution (ICO) was used as primary reference technique. DESIGN: A prospective clinical study. SETTING: A teaching hospital, single center. PARTICIPANTS: Twenty-six cardiac surgery patients. INTERVENTIONS: Perioperative CO measurements. MEASUREMENTS AND MAIN RESULTS: CO was assessed at predefined measurement points. FCO(radial), FCO(femoral), and PCO were recorded after the induction of anesthesia, after sternotomy, at skin closure, after intensive care unit transfer, and during intensive care unit stay 12 and 24 hours after study initiation. ICO was determined as the mean of 3 bolus injections. Bland-Altman analysis revealed comparable mean bias and limits of agreement for FCO(radial), FCO(femoral), and PCO when compared with ICO. There was a decreased agreement for all devices in the postoperative period. However, a consistently close agreement was observed for the direct comparison between FCO(radial) and FCO(femoral). CONCLUSIONS: Performance of the FloTrac/Vigileo system via radial as well as femoral access and the PiCCOplus monitoring for cardiac output measurement were comparable when tested against intermittent thermodilution in cardiac surgery patients.

Assessment of stroke volume variation for prediction of fluid responsiveness using the modified FloTrac and PiCCOplus system.

INTRODUCTION: Stroke volume variation (SVV) has repeatedly been shown to be a reliable predictor of fluid responsiveness. Various devices allow automated clinical assessment of SVV. The aim of the present study was to compare prediction of fluid responsiveness using SVV, as determined by the FloTrac/Vigileo system and the PiCCOplus system. METHODS: In patients who had undergone elective cardiac surgery, SVVFloTrac was determined via radial FloTrac sensor, and SVVPiCCO and pulse pressure variation were assessed via a femoral PiCCO catheter. Stroke volume was assessed by transpulmonary thermodilution. All variables were recorded before and after a volume shift induced by a change in body positioning (from 30 degrees head-up position to 30 degrees head-down position). Pearson correlation, t-test, and Bland-Altman analysis were performed. Area under the curve was determined by plotting receiver operating characteristic curves for changes in stroke volume in excess of 25%. P < 0.05 was considered statistically significant. RESULTS: Body positioning resulted in a significant increase in stroke volume; SVVFloTrac and SVVPiCCO decreased significantly. Correlations of SVVFloTrac and SVVPiCCO with change in stroke volume were similar. There was no significant difference between the areas under the curve for SVVFloTrac and SVVPiCCO; the optimal threshold values given by the receiver operating characteristic curves were 9.6% for SVVFloTrac (sensitivity 91% and specificity 83%) and 12.1% for SVVPiCCO (sensitivity 87% and specificity 76%). There was a clinically acceptable agreement and strong correlation between SVVFloTrac and SVVPiCCO. CONCLUSION: SVVs assessed using the FloTrac/Vigileo and the PiCCOplus systems exhibited similar performances in terms of predicting fluid responsiveness. In comparison with SVVPiCCO, SVVFloTrac has a lower threshold value.