MULTIPLANE TRANSESOPHAGEAL ECHOCARDIOGRAPHIC DOPPLER IMAGING ACCURATELY DETERMINES CARDIAC-OUTPUT MEASUREMENTS IN CRITICALLY ILL PATIENTS

Objectives: To compare cardiac output and stroke volume measured by multiplane transesophageal Doppler echocardiography with that measured by the thermodilution technique. Design: Prospective direct comparison of paired measurements by both techniques in each patient. Setting: Cardiac surgery and myocardial infarction intensive care units. Patients: Twenty-nine patients, mean age (+/- SD) 67 +/- 8 years. Nineteen had undergone open heart surgery and 10 had suffered acute myocardial infarction. Methods: Cardiac output and stroke volume were measured simultaneously by the thermodilution technique and multiplane transesophageal Doppler echocardiography via the transgastric view (119 +/- 8 degrees) with the sample volume positioned at the level of the left ventricular outflow tract. Results: Stroke volume and cardiac output measurements were obtained in 29 of 33 patients (88%). Mean values were 50 +/- 13 mt and 4.8 +/- 1.3 L/min by Doppler and 51 +/- 14 mt and 4.9 +/- 1.4 L/min by thermodilution (r=0.90, r=0.91, p<0.001). The mean differences in values obtained with the two techniques were 1 +/- 6 mt (2 +/- 12%) and 0.1 +/- 0.7 L/min (2 +/- 12%). Conclusions: Multiplane transesophageal echocardiography enhances the ability to estimate accurately cardiac output and stroke volume by providing new access to left ventricular outflow tract in critically ill patients.