Management of Hypotension: Implications for Noncardiac Surgery and Intensive Care

Abstract

In surgical and critically ill patients, hypotension is common and associated with adverse outcomes. Several definitions of hypotension have been suggested; one proposed by many authors assumes that a mean arterial pressure (MAP) of <65 mmHg should be avoided. Using relative thresholds to define hypotension seems physiologically appropriate but strong evidence for its superiority to using absolute thresholds is missing, probably due to difficulties in defining an individual patient’s baseline blood pressure. In the absence of clear definitions of hypotension, defining it for each individual patient while simultaneously respecting an absolute minimum threshold (e.g., MAP ≤65 mmHg) seems reasonable. The need for continuous blood pressure monitoring to also detect short episodes of hypotension should be considered carefully. Hemodynamic therapy should not be limited to blood pressure management but also include blood flow (i.e., cardiac output) optimization. Goal-directed therapy reduces postoperative complications in surgical patients, while in critically ill patients its beneficial effect is not proven by multicenter studies. As goal-directed therapy is not a well-defined concept, it should be tailored to the individual patient’s needs, depending on the underlying condition. Newly introduced hemodynamic variables, such as the peak derivative of left ventricular pressure and the dynamic arterial elastance, might contribute to the optimization of hemodynamic management. In the future, continuous, noninvasive hemodynamic monitoring and algorithms able to predict hypotensive events before their occurrence will attract increasing interest.