Transesophageal echocardiography (TEE) is a semi-invasive diagnostic tool which allows a unique intraoperative visualization of cardiac chambers and valves. It is mainly used for intraoperative monitoring during cardiac surgery and in cardiopathic patients undergoing major non cardiac surgical procedures. TEE gives a beat-to-beat assessment of cardiac morphology and function, it is less invasive and more readily performed than pulmonary artery catheterization, and it allows an etiological diagnosis of hemodynamic problems. Based on TEE data, the anesthesiologist is able to modify in real time vasoactive therapy and fluid management. TEE data concern: 1) preload: left ventricular endodiastolic area is measured and this is considered an index of volemia; 2) systolic function: the circumferential shortening fraction, which correlates with LV ejection fraction, is measured; 3) onset of ischemia: ischemia is detected as a regional modification of normal kinetics; 4) causes of hemodynamic instability; 5) assessment of sovrahepatic anastomoses during liver transplantation.
Blood Volume Cardiac Surgical Procedures