title: Transesophageal Doppler cardiac output monitoring: performance during aortic reconstructive surgery.
abstract: Transesophageal Doppler (TED) monitoring provides continuous, noninvasive monitoring of cardiac output by measurement of aortic flow velocities. Because of the effects on aortic flow dynamics resulting from atherosclerosis, aortic cross-clamping, and wide variations in arterial blood pressure, the validity of TED monitoring during aortic surgery is unresolved. The authors prospectively evaluated a second-generation TED cardiac output monitor in 42 patients undergoing aortic reconstructive surgery. Four hundred eighty-nine simultaneous measurements of TED and thermodilution cardiac output were obtained. Transesophageal Doppler measurements were highly correlated to thermodilution measurements (R = 0.94); however, Bland-Altman analysis revealed a moderate error in the TED measurements (2 SD of the bias = 1.4 L/min). Trending analysis showed that TED monitoring accurately tracked changes in thermodilution cardiac output. Placement of an aortic cross-clamp resulted in significant reductions in the accuracy of Doppler measurements. Arterial blood pressure variations did not systematically affect the accuracy of the transesophageal technique. Limitations of TED monitoring, including a difficult calibration procedure, poor performance during aortic cross-clamping, and the need for probe repositioning, suggest further development is warranted.
authors.affiliation: Department of Anesthesiology, Yale University School of Medicine, New Haven, Connecticut 06510.
authors.forename: A C
authors.initials: AC
authors.lastname: Perrino
authors.forename: J
authors.initials: J
authors.lastname: Fleming
authors.forename: K R
authors.initials: KR
authors.lastname: LaMantia
mesh_terms: D001012:Aorta, Abdominal / Q000601:surgery*; D002302:Cardiac Output; D015150:Echocardiography, Doppler / Q000379:methods*; D006801:Humans; D016343:Monitoring, Intraoperative / Q000379:methods*; D011446:Prospective Studies; D013815:Thermodilution