Multiplane transesophageal echocardiographic Doppler imaging accurately determines cardiac output measurements in critically III 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°) 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 mL and 4.8 ± 1.3 L/min by Doppler and 51 ± 14 mL 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 mL (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.