Continuous noninvasive measurement of aortic blood flow in critically ill patients with a new esophageal echo-Doppler system.

PURPOSE: Determination of aortic blood flow (ABF) using esophageal Doppler has been proposed as a low invasive hemodynamic monitoring method. The esophageal echo-Doppler Dynemo 3000 (Sometec Inc., Paris, France) system, recently available on the market, is an original device measuring simultaneously, and at the same anatomic level, aortic diameter, and blood flow velocity. Until now, this material has been used exclusively for peroperative monitoring. The objectives of the study were to assess the feasibility and reliability of use for continuous measurements of ABF in hemodynamically compromised intensive care unit patients; and to compare ABF values and its change induced by preload manipulation with the cardiac output (CO) values measured simultaneously by the standard thermodilution method.

MATERIALS AND METHODS: Sixty simultaneous measurements of ABF and CO were performed in 22 intensive care unit patients. In 16 hypovolemic patients, Doppler and thermodilution measurements were repeated after fluid replacement.

RESULTS: Applicability of the method was 84.6% (failure of the echo-Doppler method in 4 of 26 eligible patients). Coefficient of variation of echo-Doppler-derived ABF was 3.25 +/- 2.26%. Interobserver variability was 3.3 +/- 1.6%. Close linear relationship was found between ABF and CO (r = 0.92). Average ABF/CO ratio was 73 +/- 10%, but significant variation was observed after fluid replacement.

CONCLUSIONS: The echo-Doppler Dynemo 3000 system allows reliable continuous measurements of ABF in intensive care unit patients, both easily and safely.