Chapter 38 - Pulmonary hypertension

Abstract

Pulmonary hypertension (PH), defined as a mean pulmonary arterial pressure greater than 25 mm Hg, is the result of a number of pathological processes and demands vigilance in the operating room. Caution should be taken to avoid dramatic shifts in hemodynamics and volume status, thus the choice of anesthetic modality and induction strategy should be planned carefully. Perioperative management centers around optimization of the underlying cause, avoidance of hypoxia, hypercarbia, and acidosis, and the administration of medications, either inhaled or intravenous, specifically tailored to improve pulmonary arterial pressure and to support left and right ventricular function. The choice of vasopressor and inotropic agent should be dictated, not only by the efficacy of these mediations, but also their side effect profiles and actions on the pulmonary vasculature. Inhaled agents, such as nitric oxide and epoprostenol, may be beneficial depending on the source of PH. Ventilator management, especially optimization of positive end expiratory pressure, is crucial to avoid hypoxic pulmonary vasoconstriction, which elevates pulmonary arterial pressures. The complex interaction between cardiac and respiratory physiology in these patients may necessitate more invasive monitoring, including intraarterial blood pressure, pulmonary arterial catheterization, and transesophageal echocardiography.