Measurement of cardiac output by transoesophageal echocardiography: A comparison of two Doppler methods with thermodilution

This study assessed the agreement between three methods of cardiac output ( CO) measurement, thermodilution the current clinical standard and two trans oesophageal echocardiographic techniques. Measurements were performed in 37 patients using thermodilution, continuous wave Doppler across the aortic v alve and pulsed wave Doppler positioned irt the left ventricular outflow tr act, The aortic valve area was measured by direct planimetry); and the left ventricular outflow tract area was calculated from ifs diameter: Weighted least products regression analysis was employed to detect bias, and standar d deviation of the difference (SDdiff) was calculated There was no fixed bi as but there was proportional bias between continuous wave Doppler arm ther modilution methods (SDdiff 0.92 l/min). There was Fred bias but not proport ional bias between pulsed wave and thermodilution methods (SDdiff 1.1 l/min ). There was neither fixed nor proportional bias between poised wave and co ntinuous rt ave Doppler methods (SDdiff 1.1 l/min). The transoesophageal Do ppler methods described carl be clinical alternatives to thermodilution car diac output measurement.