Echocardiography in Prone Positioned Critically Ill Patients: A Wealth of Information from a Single View

Abstract

In critically ill patients, standard transthoracic echocardiography (TTE) generally does not facilitate good image quality during mechanical ventilation. We propose a prone-TTE in prone positioned patients, which allows clinicians to obtain a complete apical four-chamber (A-4-C) view. A basic cardiac assessment can be performed in order to evaluate right ventricle function and left ventricle performance, even measuring objective parameters, i.e., tricuspid annular plane systolic excursion (TAPSE); pulmonary artery systolic pressure (PAP), from the tricuspid regurgitation peak Doppler velocity; RV end-diastolic diameter and its ratio to left ventricular end-diastolic diameter; the S’ wave peak velocity with tissue Doppler imaging; the ejection fraction (EF); the mitral annular plane systolic excursion (MAPSE); diastolic function evaluation by the mitral valve; and annular Doppler velocities. Furthermore, by tilting the probe, we can obtain the apical-five-chamber (A-5-C) view, which facilitates the analysis of blood flow at the level of the output tract of the left ventricle (LVOT) and then the estimation of stroke volume. Useful applications of this technique are hemodynamic assessment, titration of fluids, vasoactive drugs therapy, and evaluation of the impact of prone positioning on right ventricle performance and right pulmonary resistances. We believe that considerable information can be drawn from a single view and hope this may be helpful to emergency and critical care clinicians whenever invasive hemodynamic monitoring tools are not available or are simply inconvenient due to clinical reasons.

Echocardiogram by apical-subcostal protocol in prone position during invasive mechanical ventilation in cardiovascular intensive care unit

“…We obtained a high assessment rate for the LV apical 4-chamber, whereas there was a low rate for LV 2 and 3-chamber compared with the supine group. However, the LV apical 4-chamber, and its tilt to obtain a 5-chamber, is sufficient to obtain an adequate cardiac assessment [ 10 ]. VTI LVOT was achieved in a large number of patients, which is helpful in estimating the cardiac output, adjusting inotropic treatment, and assessing the fluid responsiveness [ 11 ].…”