Hemodynamic Instability in Sepsis: Bedside Assessment by Doppler Echocardiography

Abstract

Septic shock is associated with important hemodynamic alterations, including absolute or relative decrease in central blood volume (1), systolic alterations of left ventricular (LV) (2, 3) and right ventricular (RV) (4) function, and severe peripheral vasodilatation responsible in part for alterations in regional blood flow distribution and probably linked to outcome (5). Hemodynamic treatment of septic shock requires blood volume expansion, which has proved to enhance survival if not delayed (6), and vasoactive support with catecholamines, according to the hemodynamic status (7). For a long time, assessment of hemodynamic instability in sepsis was based on right heart catheterization at the bedside. Recently, the Task Force of the American College of Critical Care Medicine reiterated the usefulness of right heart catheterization in guiding hemodynamic support in patients requiring more than an initial blood volume expansion (7). Concerns about the data obtained by this technique, and their interpretation in a mechanically ventilated patient, are not new (8). Moreover, this technique has been criticized for its invasiveness and associated specific complications (9). However, large cooperative clinical trials have not demonstrated an increase in mortality carried by right heart catheterization (10, 11). We abandoned right heart catheterization in our unit in 1990 and have replaced it by routine echocardiography. Since then, all patients hospitalized with septic shock have been monitored using echocardiography as a noninvasive bedside procedure. In our daily practice, echocardiography is performed after physical examination in all hemodynamically unstable patients and repeated immediately after each major hemodynamic intervention. For this purpose, the frozen multiplane probe can be kept in the esophagus for the time needed to assess the results of a major hemodynamic intervention (10–20 minutes). This strategy is original, few French teams use it, and no trial has demonstrated the usefulness of echocardiography in severe sepsis. But the quality of the data obtained and the growing demand for training from intensivists have convinced us that this procedure will be widely used in the future. Data from echocardiographic evaluation of a series of 183 patients have been published, emphasizing that a large spectrum of changes in ventricular systolic function can be observed in