Critical Care Ultrasonography

Abstract

The use of bedside ultrasonography in the intensive care unit continues to expand due to its broad utility, including diagnosis of various conditions, evaluation of hemodynamics, and improvement in the speed and safety of certain bedside procedures. In this review, the reader will gain a better understanding of the physical properties of ultrasound waves and potential artifacts. The five standard views to perform a basic echocardiographic evaluation are described. This examination provides an adequate assessment of the left ventricle, helping to differentiate acute coronary syndrome, stress cardiomyopathy, and regional or global left ventricular dysfunction. Right ventricular function can be assessed qualitatively or, if desired, quantitatively via measurement of tricuspid annular plane excursion. Echocardiography also allows for assessment of volume status, detection of cardiac tamponade, and signs of hemodynamically significant pulmonary embolism. We also describe bedside ultrasound use for pulmonary assessment and for guidance of thoracentesis. Lung ultrasonography is very sensitive for the detection of pneumothoraces and pleural effusions. The lung parenchyma may also be evaluated by identifying various artifacts such as A-lines and B-lines to delineate underlying pulmonary pathology. Understanding these artifacts allows an experienced practitioner to detect various pathologies such as pneumonia, cardiogenic pulmonary edema, atelectasis, and other conditions. Finally, we discuss abdominal ultrasonography, including the performance of a focused assessment with sonography in trauma examination, performance of a paracentesis, and diagnosis of a pneumoperitoneum. This review contains 11 figures, 1 table, and 53 references. Key words: bedside ultrasonography, echocardiography, focused assessment with sonography in trauma (FAST), focused cardiac ultrasonography (FoCUS), point-of-care ultrasonography