Postoperative pulmonary hypertension: etiology and treatment of a dangerous complication

Postoperative pulmonary hypertension is a challenging and feared complication of many types of surgery, including lung and heart transplantation, pulmonary thromboendarterectomy, congenital-heart-disease repair, and others. The most severe manifestation is acute right heart syndrome, characterized by right heart failure and cardiovascular collapse-a daunting therapeutic challenge associated with a high mortality. Patients with postoperative pulmonary hypertension must be carefully evaluated to identify reversible contributing factors such as fluid and metabolic imbalance, hypoxemia, and right heart ischemia. A pulmonary arterial catheter and echocardiogram are recommended for evaluation, although their value has not been established in carefully designed trials. Basic principles of management include maintenance of systemic perfusion pressure, optimization of cardiac inotropy, use of lung-protective ventilator strategies, and attempting to reduce right-ventricular afterload using pulmonary vasodilators. Unfortunately, controlled trials upon which to base therapy are lacking, and most approaches are supported only by uncontrolled or anecdotal evidence. Better understanding of the pathophysiology of right heart failure and controlled trials testing therapeutic approaches are needed if we are to make progress in treating this heretofore highly mortal condition.