NONINVASIVE MONITORING OF CARDIAC-OUTPUT IN CRITICALLY ILL PATIENTS USING TRANSESOPHAGEAL DOPPLER

Measurement of cardiac output using thermodilution technique in mechan ically ventilated patients is associated with significant morbidity. T he goal of the present study was to assess the validity of cardiac out put measurement using transesophageal Doppler in critically ill patien ts. Forty-six patients from three different intensive care units under went 136 paired cardiac output measurements using thermodilution (COTH ) and transesophageal Doppler (COTED). In addition, simultaneous supra sternal Doppler and indirect calorimetry (Fick principle) were used to measure cardiac output in 26 patients from one center. A good correla tion was found between COTH and COTED (r = 0.95), with a small systema tic underestimation (bias = 0.24 L/min) using transesophageal Doppler. The limits of agreement between COTH and COTED were +2 L/min and -1.5 L/min. Variations in cardiac output between two consecutive measures using either transesophageal Doppler or thermodilution techniques were similar in direction and magnitude (bias = 0 L/min; limits of agreeme nt = +/-1.7 L/min). Suprasternal Doppler and indirect calorimetry yiel ded similar correlations and agreements in the subset of patients in w hom they were used. These results confirm that transesophageal Doppler can provide a noninvasive, clinically useful estimate of cardiac outp ut and detect hemodynamic changes in mechanically ventilated, critical ly ill patients.