Anesthetic concerns in lung transplantation for severe pulmonary hypertension

Lung transplantation has become a consolidated treatment for patients with severe pulmonary hypertension (PH). Several difficulties are encountered during the procedure in such candidates, who are still recognized as more severely affected by perioperative morbility and mortality than those undergoing lung transplantation for other diseases. Right ventricular (RV) enlargement with tricuspid regurgitation, small left ventricle (LV) with an asymmetric hypetrophic wall, interventricular septal shift toward the left, with ventricular stiffness and diastolic incompetence, are typical preoperative echocardiographic findings of end-stage PH. A smooth induction and tracheal intubation will help prevent hypertensive crisis in highly susceptible candidates. Uncompensated vasodilatation or myocardial depression caused by anesthetics and mechanical ventilation may be responsible for acute RV dysfunction associated with low systemic blood pressure. Resuscitation and emergency adoption of cardiopulmonary by-pass (CPB) has been described for near-fatal anesthesia induction. Cardiovascular instability can develop after institution of one-lung ventilation and pulmonary artery clamping. An acute increase in pulmonary pressure results in a decrease in RV ejection fraction and then in acute RV failure. Interdependence of the right and left ventricles occurs such that RV function can alter LV function. Early detection of impending circulatory and/or respiratory deterioration is warranted to prevent an irreversible decline in cardiac output, resulting in hazardous cardiac arrest. Inhaled nitric oxide represents the first choice for treatment of PH and RV failure associated with systemic hypotension during lung transplantation. Intraoperative situations requiring CPB must be identified before development of systemic shock, which represents a late ominous sign of RV failure.