Transesophageal Echocardiography During Lung Transplantation

Abstract

Transesophageal echocardiography (TEE) is a semiinvasive monitoring technique increasingly used in cardiac surgery and in major noncardiac surgery for patients with known or supposed cardiac or coronary problems. During lung transplantation (LTx), the close interrelation between heart and lung function makes TEE an invaluable tool for instantly monitoring the physiopathological situation in the subsequent steps of the intervention. In patients scheduled for LTx, induction of anesthesia could be a dangerous moment with the possibility of cardiogenic shock if pulmonary hypertension (PH) exists; pneumatic tamponade is also possible in patients with emphysema caused by α 1-antitrypsin deficiency, with subsequent cardiac insufficiency. One-lung ventilation is a critical phase during LTx; hypoxemia resulting from ventilation of a diseased dependent lung could impair heart oxygenation, particularly if tachycardia is present. Clamping of the pulmonary artery before pneumonectomy could exacerbate cardiac afterload, especially in patients with previous PH. High transmural pressure, linked with low systemic pressure, makes right ventricle (RV) perfusion pressure inadequate. Hypoxemia and PH are the most frequent causes of intraoperative RV decompensation. In this special setting, TEE is irreplaceable in informing the anesthesiologist about the correct time for extracorporeal oxygenation. Lung reperfusion brings with it the possibility of coronary gaseous embolism, easily detected with TEE. After LTx, TEE can be used to detect strictures, thrombi, or permeability of pulmonary venous anastomoses. To summarize, intraoperative TEE during LTx contributes to the immediate recognition of critical events and allows for rapid therapeutic interventions.