CO assessment by suprasternal Doppler in critically ill patients: comparison with thermodilution
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Updated: Oct 13, 2026
Continuous Venous-Arterial Doppler Ultrasound During a Preload Challenge
Published on: January 20, 2023
J Y Lefrant1, M Benbabaali, J Ripart
1Fédération d'Anesthésie Douleur Urgences Réanimation, Centre Hospitalier Universitaire de Nîmes, France.
Objective:
Comparison of suprasternal Doppler (SST) and thermodilution (TD) for the measurement of cardiac output (CO) in critically ill patients.
Design:
Prospective study.
Setting:
Intensive care unit of a university hospital.
Patients And Participants:
65 consecutive critically ill patients requiring a pulmonary artery catheter.
Interventions:
Paired CO measurements were made simultaneously using SST and TD by two independent operators. The time to obtain a CO value by SST was measured. Correlation coefficients and the linear regression equation were determined. A Bland and Altman diagram was plotted. A Bland and Altman diagram was also plotted for the level of cardiac index (CI) values (low: CI < 2.5 l min(-1) m(-2); normal: 2.5 < or = CI < or = 4.5 l min(-1) m(-2); high: CI > 4.5 l min(-1) m(-2)).
Measurements And Results:
In seven patients SST failed to measure CO. In the remaining 58 patients 314 paired CO measurements were performed. The mean time to measure CO by SST was 73 +/- 45 s. The equation of linear regression was: SST(CO) = 0.84 TD(CO) + 1.39. The correlation coefficient was 0.84. The bias between SST and TD was -0.2 +/- 1.4 l min(-1). Biases were -0.23 +/- 0.50, -0.20 +/- 0.68, and 0.25 +/- 0.92 l min(-1) m(-2) for low, normal, and high levels of CI, respectively.
Conclusion:
SST does not accurately measure CO but allows a rapid assessment of CI level in critically ill patients.
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