Complications during vascular surgery: basic principles and management of arterial hypotension and hypertension

The chapter discusses the pathophysiology of arterial hypotension and hypertension in the operating room setting. The main goal and structure of the discussion is to construct a Decision Tree of the pathophysiology of arterial hypo- and hypertension. The discussion starts with the notion that blood pressure is dependent on only two variables, namely cardiac output and vascular resistance. In turn, cardiac output depends only on stroke volume and heart rate. Then, stroke volume depends only on venous return and the pump function of the heart, which in turn would depend only on the contractility and the impedance to the ejection. The next step discusses the determinant of venous return as a function of peripheral venous pressure, central venous pressure and venous resistance. At the end of the discussion the conclusion is made that the main determinants of blood pressure would be vascular tone, arterial and venous separately, circulating blood volume and the pump function of the heart. The following part of the chapter discusses the diagnosis of one or another pathophysiological condition for arterial hypo- or hypertension, as well as possible pharmacological interventions.