Pulmonary hypertension in the perioperative period-focus on current and emerging therapies

Patients with pulmonary hypertension continue to present for both cardiac and non-cardiac surgery in greater numbers worldwide, and are usually managed by cardiothoracic anesthesiologists. These specialists have traditionally used intravenous therapy in the operating room to manipulate hemodynamics (cardiac output systemic and pulmonary vascular resistance), to effectively manage these high risk patients. General anesthesia involves the administration of both intravenous and inhaled drug therapy to achieve the desired goals, i.e. analgesia, amnesia, muscle relaxation and blockade of autonomic activity. Anesthesiologists are the experts in the use and titration of drugs that are administered through the inhaled route. However, this method of drug delivery presents many challenges, notably timing, dosage accuracy, rapid titratability and consistency of drug delivery. In patients with severe pulmonary hypertension, arguably the most rapid method of treating acutely reactive pulmonary vasculature would involve drugs that directly act upon the pulmonary endothelium. In the perioperative period, pulmonary hypertension and right ventricular failure are high predictors of morbidity and mortality and present significant challenges to the anesthesiologist. In this article, we will focus on the current status of intravenous and inhaled therapy of these conditions, including concerned recent patents.