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Pulse contour analysis for cardiac output measurement in patients after off-pump coronary artery bypass grafting: a comparison of FloTrac and PiCCOpluswith intermittent thermodilution


Pulse contour analysis calibrated by transpulmonary thermodilution (PiCCOplus; Pulsion Medical Systems, Munich, Germany) has shown in the past years to be a reliable alternative to the pulmonary artery catheter for cardiac output (CO) assessment in different clinical settings [1,2]. A new pulse contour analysis device, which does not need an external calibration (FloTrac/ Vigileo; Edwards Lifesciences, Irvine CA, USA), recently became available. The aim of this study was to compare the CO determined by the FloTrac sensor (FCO) and by the PiCCOplus system (PCO) with the CO assessed by intermittent thermodilution (ICO).


With local ethic committee approval, patients after elective off-pump coronary artery bypass grafting were studied under different conditions in the ICU. For one set of data (A = 'haemodynamic stable') the CO was assessed following haemo-dynamic stabilization and calibration of the PiCCOplus. Triplicate FCO and PCO values were recorded within 3 min before the ICO was determined by three repeated injections at four time points with intervals of 15 min. For the second set of data (B = 'haemo-dynamic changes') triplicate FCO, PCO and ICO measurements were recorded 15 min after inducing CO changes by different body positions (supine 1, 30° head-up, 30° head-down, supine 2). Mean arterial pressure was maintained ≥70 mmHg by adjustment of norepinephrine infusion. Statistical analysis was performed using ANOVA with post-hoc Bonferroni/Dunn correction, t test and Bland–Altman analysis for absolute CO values and percentage changes (Δ = trend analysis) of CO during A and B. P < 0.05 was considered statistically significant.


Seventy-two matched sets of data were obtained from nine patients (ASA III, female/male ratio = 2/7, age = 63.0 ± 9.5 years, BMI = 24.8 ± 2.2 kg/m2). CO values recorded during A ranged from 3.30 to 6.56 l/min, no significant CO changes between measurement points were recorded (ΔFCO = -0.8 ± 14.8%, ΔPCO = -0.9 ± 15.3%, ΔICO = -1.9 ± 12.8%). Bland-Altman analysis revealed a mean bias ± 2SD (limits of agreement) of -0.13 ± 1.08 l/min for FCO-ICO and of 0.08 ± 0.91 l/min for PCO-ICO. Differences of ΔCO were comparable (mean bias ± 2SD = 1.1 ± 24.8% for ΔFCO – ΔICO and 1.0 ± 24.8% for ΔPCO – ΔICO). A range of CO values from 2.85 to 8.60 l/min were obtained during B with significant changes of FCO, PCO and ICO between the measurement points (Table 1 and Fig. 1). The mean bias ± 2SD was -0.14 ± 1.82 l/min for FCO-ICO and -0.17 ± 1.13 l/min for PCO-ICO. For ΔFCO – ΔICO a mean bias ± 2SD of -2.8 ± 36.4% was observed, whereas for ΔPCO – ΔICO the mean bias ± 2SD was 0.9 ± 13.2%.

Table 1
Figure 1

CO changes induced by body positioning.


These preliminary results indicate that cardiac output in patients after off-pump coronary artery bypass grafting can be reliably monitored by both tested pulse contour analysis devices (FloTrac and PiCCOplus system) during stable haemodynamic conditions. However, the FloTrac system showed a tendency to overestimate rapid decreases and increases of cardiac output when compared with the PiCCOplus system.


  1. 1.

    Della Rocca G, et al: Can J Anaesth. 2003, 50: 707-711. 10.1007/BF03018714.

    Article  PubMed  Google Scholar 

  2. 2.

    Felbinger TW, et al: J Clin Anesth. 2005, 17: 241-248. 10.1016/j.jclinane.2004.06.013.

    Article  PubMed  Google Scholar 

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Hofer, C., Button, D., Jacomet, A. et al. Pulse contour analysis for cardiac output measurement in patients after off-pump coronary artery bypass grafting: a comparison of FloTrac and PiCCOpluswith intermittent thermodilution. Crit Care 10, P323 (2006).

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  • Cardiac Output
  • Pulmonary Artery Catheter
  • Ethic Committee Approval
  • Altman Analysis
  • Transpulmonary Thermodilution