Goal-directed echocardiography (GDE) in the intensive care unit (ICU) setting is defined as a basic echocardiogram done with specific, focused objectives. It comprises a rapid, real-time, visual, two-dimensional echocardiographic assessment of cardiac preload, global and regional wall motion, and the pericardium at the bedside using either transesophageal or transthoracic methods. This chapter will discuss the rationale for intensivist-performed GDE, scope of GDE skills and knowledge, indications for GDE, choosing between transesophageal and transthoracic examinations, performance and interpretation of the GDE examination, equipment considerations, and training for acquiring the necessary skills for GDE.
Echocardiography has been predominantly performed by cardiologists who undergo extensive training for the performance of comprehensive echocardiographic examinations.1 Over the past 1–20 years physicians, particularly in the fields of anesthesiology2 and emergency medicine (EM),3–6 have adopted components of the echocardiographic exam that are particularly suited to the unique needs of their particular patient population. Training guidelines have been published in basic and advanced perioperative comprehensive echocardiography for anesthesiologists and EM physicians.5–7 Ultrasound is now an accepted part of the EM curriculum, having been adopted by the American College of Graduate Medical Education (ACGME) and now incorporated into residency training programs.8 However, because significant differences exist between the use of echocardiography by these disciplines and that of critical care, guidelines specific for intensive care physicians need to be circumscribed.
Echocardiography provides information that is essential in clinical decision-making in critically ill patients to assess cardiac function and relative volume status. When compared with the indirect hemodynamic data from the relatively more invasive process of pulmonary artery catheterization,9–12 echocardiography provides direct visualization of cardiac anatomy, and information on abnormal biventricular function and volume status as well as potentially compromising pericardial effusions. Goal-directed echocardiography in hemodynamically unstable patients, performed at the bedside by the physician caring for the patient, can provide immediate critical information about the cardiovascular system that is not available by other means and that can impact therapy in 30–40% of patients.13,14 The aim of intensivist-performed GDE is to rapidly assess the hemodynamically unstable patient at the bedside to provide an immediate, personalized treatment in the ICU setting. While the standard comprehensive echocardiographic examination, which encompasses M-mode, 2D-echo, pulsed, continuous-wave, and color Doppler with calculations, requires approximately one hour,15 the ICU-focused echo examination pertinent only to the immediate clinical scenario greatly reduces image acquisition and interpretation time while still maintaining diagnostic integrity16,17; it favors specificity of diagnosis over sensitivity.
Performance of an ICU GDE requires an understanding of the indications for GDE in critically ill patients, the principles of ultrasound, and cognitive and technical skills to perform GDE in the ICU in critically unstable patients. The cognitive elements of performance of basic echocardiography include understanding of basic ultrasound principles, “knobology” of the machine, and a basic understanding of cardiac anatomy and function. The method of probe placement ...