Bedside ultrasonography: Applications in critical care: Part I

Abstract

There is increasing interest in the use of ultrasound to assess and guide the management of critically ill patients. The ability to carry out quick examinations by the bedside to answer specific clinical queries as well as repeatability are clear advantages in an acute care setting. In addition, delays associated with transfer of patients out of the Intensive Care Unit (ICU) and exposure to ionizing radiation may also be avoided. Ultrasonographic imaging looks set to evolve and complement clinical examination of acutely ill patients, offering quick answers by the bedside. In this two-part narrative review, we describe the applications of ultrasonography with a special focus on the management of the critically ill. Part I explores the utility of echocardiography in the ICU, with emphasis on its usefulness in the management of hemodynamically unstable patients. We also discuss lung ultrasonography - a vastly underutilized technology for several years, until intensivists began to realize its usefulness, and obvious advantages over chest radiography. Ultrasonography is rapidly emerging as an important tool in the hands of intensive care physicians.

Use of focus assessed transthoracic echocardiography (FATE) in the veterinary emergency room

“…However, serial echocardiographic studies are necessary to assess the response of patients to therapeutic interventions, since M mode estimates may be affected by factors influencing preload and afterload. Furthermore, ejection fraction may be over-estimated in patients with vasodilatation due to low systemic vascular resistence (CHACKO & BRAR, 2014).…”

“…Moreover, the presence of hypotension, combined with a decrease in ventricular function, requires optimization of fluid therapy or inotropic assistance (CHACKO & BRAR, 2014). The purpose of this examination is to facilitate and expedite therapeutic choices; however, FATE will differentiate normal or minimally compromised patients from abnormal or significantly compromised ones (LABOVITZ et al, 2010), since the systolic function is dependent on factors such as preload, afterload, contractility, distensibility, coordinated contraction and heart rate (BOON, 2011).…”

“…Left ventricular systolic function can be visually evaluated (subjective evaluation) or by estimating the ejection fraction, which is the percentage of diastolic volume ejected during systole. Quantification of the ejection fraction can be performed in the same way in both people and animals, through the parasternal short axis image, from which the left ventricle internal diameter during systole and diastole can be measured using M mode (BOON, 2011;CHACKO & BRAR, 2014). However, serial echocardiographic studies are necessary to assess the response of patients to therapeutic interventions, since M mode estimates may be affected by factors influencing preload and afterload.…”

“…The interventricular septum should also be evaluated, in cases of overload volume in the right side of the heart the septum is deviated to the left. Under these conditions, the left ventricle loses its circular shape and assumes a "D" form that can be viewed in the parasternal short axis image (CHACKO & BRAR, 2014). In veterinary medicine right ventricle function is most commonly visually assessed (subjective evaluation).…”

“…The apical four and five chambers images, with the visualization of the atriums and ventricles, interatrial and interventricular septum, aorta and left ventricle outflow tract are performed. Additionally, images in the parasternal long and short axis are acquired (CHACKO & BRAR, 2014). In veterinary medicine a single study was performed to verify whether training of veterinary emergency physicians would increase the accuracy of FATE in the interpretation of cardiovascular and noncardiovascular conditions in dogs in the emergency room.…”