[Evaluation of intraoperative transesophageal echocardiography]

With the development of medical ultrasonics, anesthesiologists have recognized the usefulness of transesophageal echocardiography as an intraoperative monitoring. Intraoperative transesophageal echocardiography is now used to monitor left ventricular function and to confirm the result of surgical correction immediately after cardiac operation. In this study, we evaluated the detectability of air embolism and the effect of hemodynamic changes on physiological mitral regurgitant flow by transesophageal Doppler echocardiography (TEDE). TEDE was more sensitive than precordial Doppler ultrasound in detecting intracardiac air. TEDE could detect air inflow to the right atrium earlier than alterations in pulmonary hemodynamics. The monitoring of intracardiac air by TEDE minimized the complication by air embolism. Regarding physiological mitral regurgitation, the degree of regurgitation increased with the elevation of BP in 70% of patients. An increase in afterload seemed to cause accidental volume loading on the left heart resulting in physiological mitral regurgitation. Intraoperative monitoring of regurgitant flow by TEDE was useful for the anesthesiologist as a guide of hemodynamic management. Transesophageal echocardiography is a useful intraoperative monitoring method regardless of its several disadvantages. With further improvement of mechanical device, transesophageal echocardiography will be more often and safely performed in operating room.