Cardiac output

Abstract

The use of invasive hemodynamic monitoring in the SICU remains controversial. Singer, in an insightful review of cardiac output determination and significance, recalls the statement of Karl Ludwig: “The fundamental problems in the circulation derive from the fact that the supply of adequate amounts of blood to the organs of the body is the main purpose of the circulation while the pressures that are necessary to achieve it are of secondary importance; but the measurement of flow is difficult while that of pressure is easy so that our knowledge of flow is usually derivatory (1).” Although the technology for measuring flow exists, the value of measuring flow in improving outcomes continues to be contentious. In several studies of high-risk surgery patients, increasing oxygen transport preoperatively by manipulating cardiac output resulted in significantly better outcomes (2-4). In the critically ill patient, data are contradictory. Chapter 63 provides a review and analysis of flow manipulation in the critically ill patient.