Comparison of esophageal Doppler, pulse contour analysis, and real-time pulmonary artery thermodilution for the continuous measurement of cardiac output.

OBJECTIVE: Continuous measurement of cardiac output (CCO) is of great importance in the critically ill. However, pulmonary artery thermodilution has been questioned for possible complications associated with right heart catheterization. Furthermore, measurements are delayed in the continuous mode during rapid hemodynamic changes. A new pulmonary artery catheter CCO device (Aortech, Bellshill, Scotland) enabling real-time update of cardiac output was compared with 2 different, less-invasive methods of CCO determination, esophageal Doppler and pulse contour analysis.
DESIGN: Prospective, observational study.
SETTING: University hospital, single institution. PARTICIPANTS: Patients scheduled for elective coronary artery bypass grafting (CABG).
INTERVENTIONS: None.
MEASUREMENTS AND MAIN RESULTS: CCO measurements were analyzed using a Bland-Altman plot. Bias between CCO and pulse contour cardiac output (PCCO), and Doppler-derived cardiac output (UCCO) was (mean +/- 1 SD) -0.71 +/- 1 L/min versus -0.15 +/- 1.09 L/min, and between UCCO and PCCO -0.58 +/- 1.06 L/min. Bias was not significantly different among methods, nor were comparative values before and after cardiopulmonary bypass (p > 0.05).
CONCLUSIONS: Agreement between the CCO method and both less-invasive measurements was clinically acceptable. There were no adverse events associated with the use of either device.